Patent Publication Number: US-11382198-B2

Title: Circuit for providing power to two or more strings of LEDs

Description:
TECHNICAL FIELD 
     This disclosure relates circuits for driving and controlling strings of light-emitting diodes. 
     BACKGROUND 
     Drivers are often used to control a voltage, current, or power at a load. For instance, a light-emitting diode (LED) driver may control the power supplied to a string of light-emitting diodes. Some drivers may include a Direct Current (DC) to DC power converter, such as a buck-boost, buck, boost, or another DC to DC converter. Such DC to DC power converters may be used to control and possibly change the power at the load based on a characteristic of the load. DC to DC power converters may be especially useful for regulating current through LED strings. 
     SUMMARY 
     In general, this disclosure is directed to devices, systems, and techniques for controlling an amount of electrical current delivered to one or more light-emitting diodes (LEDs). For example, a driver circuit may supply an electrical signal to the one or more LEDs. A controller may control the one or more LEDs in order to switch the one or more LEDs from a first lighting mode to a second lighting mode. In response to the controller switching from the first lighting mode to the second lighting mode, the driver circuit may cause a magnitude of the electrical signal to temporarily increase (e.g., “overshoot”). However, the driver circuit may sink at least a portion of the electrical signal in order to prevent the magnitude of the electrical signal from increasing above a maximum electrical signal magnitude value. This may prevent the overshoot of the electrical signal from damaging the one or more LEDs. 
     In some examples, a circuit is configured to control power delivered to a string of LEDs, the circuit including a power converter configured to generate an electrical current, a switching device, and a sensor. The sensor is configured to compare a magnitude of the electrical current to a threshold. In response to the magnitude exceeding the threshold, the sensor is configured to cause the switching device to turn on in order to sink a portion of the electrical current to prevent the magnitude of the electrical current from exceeding the threshold. When the switching device is turned on, the electrical current is divided into an undesired electrical current that flows across the switching device and a desired electrical current that flows to the string of LEDs. 
     In some examples, a method for controlling power delivered to a string of LEDs includes generating, by a power converter, an electrical current and comparing, by a sensor, a magnitude of the electrical current to a threshold. In response to the magnitude exceeding the threshold, the method further includes causing, by the sensor, a switching device to turn on in order to sink a portion of the electrical current to prevent the magnitude of the electrical current from exceeding the threshold. When the switching device is turned on, the electrical current is divided into an undesired electrical current that flows across the switching device and a desired electrical current that flows to the string of LEDs. 
     In some examples, a system includes a string of LEDs, a power converter configured to generate an electrical current, a switching device, and a sensor. The sensor is configured to compare a magnitude of the electrical current to a threshold. In response to the magnitude exceeding the threshold, the sensor is configured to cause the switching device to turn on in order to sink a portion of the electrical current to prevent the magnitude of the electrical current from exceeding the threshold. When the switching device is turned on, the electrical current is divided into an undesired electrical current that flows across the switching device and a desired electrical current that flows to the string of LEDs. 
     The summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the systems, devices, and methods described in detail within the accompanying drawings and description below. Further details of one or more examples of this disclosure are set forth in the accompanying drawings and in the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating an example system for controlling an electrical signal delivered from a power converter to a set of light-emitting diodes (LEDs), in accordance with one or more techniques of this disclosure. 
         FIG. 2  is a circuit diagram illustrating a system including a circuit for controlling power to a set of LEDs using a switching device, in accordance with one or more techniques of this disclosure. 
         FIG. 3  is a circuit diagram illustrating a system including a circuit for controlling power to a set of LEDs by controlling a switching device and controlling a power converter, in accordance with one or more techniques of this disclosure. 
         FIG. 4  is a circuit diagram illustrating a system including a circuit for controlling power to a set of LEDs by controlling a power converter, in accordance with one or more techniques of this disclosure. 
         FIG. 5  is a graph illustrating a switching device mode plot, a current sensor signal plot, and an undesired current plot, in accordance with one or more techniques of this disclosure. 
         FIG. 6  is a graph illustrating a switching device mode plot, a current sensor signal plot, and an undesired current plot, in accordance with one or more techniques of this disclosure. 
         FIG. 7  is a flow diagram illustrating an example operation for controlling a switching device to sink electrical current during an electrical current overshoot, in accordance with one or more techniques of this disclosure. 
     
    
    
     Like reference characters denote like elements throughout the description and figures. 
     DETAILED DESCRIPTION 
     Some systems may use a power converter, such as a direct current (DC) to DC converter to control current supplied to a string of light emitting diodes (LEDs). This disclosure is directed to a circuit for controlling an amount of electrical current which travels from the power converter to the string of LEDs, such that an overshoot in the electrical current does not damage the string of LEDs. For example, the circuit may include a sink pathway configured to divert at least a portion of the electrical signal output from the power converter away from the string of LEDs. The sink pathway may include one or more switching devices which control whether the sink pathway diverts electrical current output from the power converter. In some cases, the circuit includes a current sensor which is configured to measure an electrical current magnitude along an electrical connection between the power converter and the string of LEDs. Based on the measured electrical current, the circuit may control the switching device in order to sink a portion of the electrical current output by the power converter. 
       FIG. 1  is a block diagram illustrating an example system  100  for controlling an electrical signal delivered from a power converter  120  to a set of LEDs  150 , in accordance with one or more techniques of this disclosure. As seen in  FIG. 1 , system  100  includes a power source  110 , a controller  112 , power converter  120 , a capacitor  130 , an inductor  140 , LEDs  150 , switching device  160 , current sensor  162 , and amplifier  170 . 
     System  100  may be configured to supply power to LEDs  150  in order to cause LEDs  150  to emit light. LEDs  150  may include one or more lighting modes, where each lighting mode of the one or more lighting modes requires a respective electrical signal. For example, the one or more lighting modes may include a low-light mode and a high-light mode. Switching LEDs  150  from the high-light mode to the low-light mode may include shorting at least one of LEDs  150  in order to decrease an amount of light emitted by LEDs  150 . Shorting at least one of LEDs  150  may cause an overshoot of an electrical current delivered from power converter  120  to LEDs  150 . System  100  may sink at least a portion of the electrical current delivered from power converter  120  to LEDs  150  in order to prevent LEDs  150  from being damaged by the electrical current. 
     Power source  110  is configured to deliver operating power to power converter  120 . In some examples, power source  110  includes a battery and a power generation circuit to produce operating power. In some examples, power source  110  is rechargeable to allow extended operation. Power source  110  may include any one or more of a plurality of different battery types, such as nickel cadmium batteries and lithium ion batteries. In some examples, a maximum voltage output of power source  110  is approximately 12V. In some examples, power source  110  supplies power within a range from 5 Watts (W) to 50 W. 
     Controller  112  may include one or more processors that are configured to implement functionality and/or process instructions for execution within accelerometer system  10 . For example, controller  112  may be capable of processing instructions stored in a memory. Controller  112  may include, for example, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or equivalent discrete or integrated logic circuitry, or a combination of any of the foregoing devices or circuitry. Accordingly, controller  112  may include any suitable structure, whether in hardware, software, firmware, or any combination thereof, to perform the functions ascribed herein to controller  112 . 
     A memory (not illustrated in  FIG. 1 ) may be configured to store information within system  100  during operation. The memory may include a computer-readable storage medium or computer-readable storage device. In some examples, the memory includes one or more of a short-term memory or a long-term memory. The memory may include, for example, random access memories (RAM), dynamic random access memories (DRAM), static random access memories (SRAM), magnetic discs, optical discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable memories (EEPROM). In some examples, the memory is used to store program instructions for execution by controller  112 . 
     Power source  110  may supply an input electrical signal to power converter  120 . Furthermore, power converter  120  may provide at least a portion of an output electrical signal to first LEDs  150 , which represent a load supplied with energy by power converter  120 . The input electrical signal, in some cases, may include an input current and an input voltage. Additionally, the output electrical signal may include an output current and an output voltage. In some cases, power converter  120  includes a DC-to-DC power converter configured to regulate an electrical signal received by LEDs  150 . In some examples, the DC-to-DC power converter includes a switch/inductor unit such as an H bridge. An H bridge uses a set of switches, often semiconductor switches, to convert electrical power. In some examples, the switch/inductor unit acts as a buck-boost converter. For instance, a buck-boost converter is configured to regulate the electrical signal received by LEDs  150  using at least two operational modes including a buck mode and a boost mode. Power converter  120  may control semiconductor switches of the buck-boost converter to alternate the mode of the buck-boost converter (e.g., change the operation mode of the buck-boost converter from buck mode to boost mode and vice versa). 
     In some examples, controller  112  is configured to output one or more signals in order to control power converter  120  to deliver a desired amount of electrical current to LEDs  150 , but this is not required. In some examples, power converter  120  operates without receiving signals from controller  112 . That is, power converter  120  is configured to operate independently from controller  112 . It may be beneficial for power converter  120  to operate based on one or more signals received from amplifier  170  rather than operating based on one or more signals received from controller  112 . In other words, power converter  120  may control an electrical current output from power converter  120  according to a feedback loop including current sensor  162  and amplifier  170 . This may allow power converter  120  to control electrical current output from power converter  120  in real-time or near real-time based on an electrical current sensed by current sensor  162 . 
     In the example illustrated in  FIG. 1 , the semiconductor switches of power converter  120  may include transistors, diodes, or other semiconductor elements. In buck mode, the buck-boost converter of power converter  120  may step down voltage and step up current from the input of power converter  120  to the output of power converter  120 . In boost mode, the buck-boost converter of power converter  120  may step up voltage and step down current from the input of power converter  120  to the output of power converter  120 . In some examples, power converter  120  is configured to regulate a current of the electrical signal received by LEDs  150  such that a current of the electrical signal remains substantially constant. 
     In some examples, power converter  120  may supply power to LEDs  150  using capacitor  130 . Capacitor  130  is an electrical circuit component configured for storing electric potential energy. Capacitor  130  may, in some examples, occupy a “charged” state, where capacitor  130  stores an amount of electric potential energy. Additionally, capacitor  130  may occupy a “discharged” state where capacitor  130  stores little or no electric potential energy. Capacitor  130  may also transition between the charged state and the discharged state. When capacitor  130  is charging, a current flows across capacitor  130 , increasing the electric potential energy stored by capacitor  130 . When capacitor  130  is discharging, the electric potential energy stored by capacitor  130  is released, causing capacitor  130  to emit an electric current. 
     Capacitor  130  may represent an output capacitor for power converter  120 . For example, power converter  120  may charge and discharge capacitor  130  in cycles so that a discharge of capacitor  130  delivers a desired amount of electrical current to LEDs  150 . For example, when LEDs  150  are operating in a high-light mode, power converter  120  may charge capacitor  130  to a first charge level and when LEDs  150  are operating in a low-light mode, power converter  120  may charge capacitor  130  to a second charge level, where the first charge level is greater than the second charge level. When controller  112  toggles LEDs  150  from the high-light mode to the low-light mode, however, power converter  120  might not be able to instantly change an amount of charge in capacitor  130 . As such, if capacitor  130  discharges shortly after controller  112  toggles LEDs  150  from the high-light mode to the low-light mode, the electrical current received by LEDs  150  in response to the discharge of capacitor  130  may represent an overshoot electrical current. System  100  may sink at least a portion of the overshoot electrical current in order to prevent the overshoot electrical current from damaging LEDs  150 . 
     Inductor  140  may be electrically connected to LEDs  150  such that LEDs  150  receive the electrical signal from power converter  120  through inductor  140 . Inductor  140  represents an electrical circuit component that resists change in a magnitude of electrical current passing through inductor  140 . In some examples, inductor  140  is defined by an electrically conductive wire that is wrapped in a coil. As electrical current passes through the coil of inductor  140 , a magnetic field is created in the coil, and the magnetic field induces a voltage across the inductor. Inductor  140  defines an inductance value, and the inductance value is the ratio of the voltage across inductor  140  to the rate of change of current passing through inductor  140 . 
     Inductor  140  may act to mitigate an overshoot of the electrical current received by LEDs  150 . For example, since inductor  140  resists a change in the magnitude of the electrical current flowing through  140 , inductor  140  may prevent the electrical current received by LEDs  150  from increasing as sharply during an electrical current overshoot as compared with a system where LEDs receive an electrical signal directly from a power converter without receiving the electrical signal through an inductor. Inductor  140  alone, however, might not be able to prevent an overshoot electrical current from damaging LEDs  150 . System  100  may sink a portion of an overshoot electrical current through switching device  180  in order to prevent the overshoot electrical current from damaging LEDs  150 . 
     Although  FIG. 1  illustrates inductor  140  as being a part of system  100 , in some cases, system  100  might not include an inductor  140  electrically connected to LEDs  150 . In some examples, amplifier  170  generates the amplifier signal to control power converter  120  and/or switching device  160  in order to prevent electrical current  159  from damaging LEDs  150  during a current overshoot without relying on an inductor to mitigate the current overshoot. In other words, system  100  may be configured to perform one or more techniques described herein without inductor  140 . 
     LEDs  150  may include any one or more suitable semiconductor light sources. In some examples, an LED of LEDs  150  may include a p-n junction configured to emit light when activated. In some examples, LEDs  150  may be included in a headlight assembly for automotive applications. For instance, LEDs  150  may include a matrix, a string, or more than one string of light-emitting diodes to light a road ahead of a vehicle. As used herein, a vehicle may refer to motorcycles, trucks, boats, golf carts, snowmobiles, heavy machines, or any type of vehicle that uses directional lighting. In some examples, LEDs  150  include a first string of LEDs including a set of high-beam (HB) LEDs and a set of low-beam (LB) LEDs. In some cases, controller  112  may toggle between activating the set of LB LEDs, activating the set of HB LEDs, activating both the set of LB LEDs and the set of HB LEDs, and deactivating both the set of LB LEDs and the set of HB LEDs. LEDs  150  may include any number of LEDs. For example, LEDs  150  may include a number of LEDs within a range from 1 to 100 LEDs. In some examples, a high-light mode of LEDs  150  may represent a mode in which the set of HB LEDs are activated. In some examples, a low-light mode of LEDs  150  may represent a mode in which the set of HB LEDs are not activated. 
     It may be beneficial for system  100  to sink at least a portion of an overshoot electrical current through switching device  160 . For example, an overshoot electrical current may cause switching device  160  to activate, causing an undesired electrical current  161  to flow through switching device  160  and allowing a desired electrical current  163  to flow through LEDs  150 . By activating switching device  160  in order to sink the undesired electrical current  161 , system  100  may prevent the current flowing through LEDs  150  from damaging LEDs  150 . In other words, switching device  160  may ensure that only the desired electrical current  163  flows through LEDs  150 , where the desired electrical current  163  does not damage the LEDs  150 . 
     Switching device  160  may, in some cases, include a power switch such as, but not limited to, any type of field-effect transistor (FET) including any combination of a metal-oxide-semiconductor field-effect transistor (MOSFET), a bipolar junction transistors (BJT), an insulated-gate bipolar transistor (IGBT), a junction field effect transistors (JFET), a high electron mobility transistor (HEMT), or other elements that use voltage and/or current for control. Additionally, switching device  160  may include n-type transistors, p-type transistors, and power transistors, or any combination thereof. In some examples, switching device  160  includes vertical transistors, lateral transistors, and/or horizontal transistors. In some examples, switching device  160  include other analog devices such as diodes and/or thyristors. In some examples, switching device  160  may operate as switches and/or as analog devices. 
     In some examples, switching device  160  includes three terminals: two load terminals and a control terminal. For MOSFET switches, switching device  160  may include a drain terminal, a source terminal, and at least one gate terminal, where the control terminal is a gate terminal. For BJT switches, the control terminal may be a base terminal. Current may flow between the two load terminals of switching device  160 , based on the voltage at the respective control terminal. Therefore, electrical current may flow across switching device  160  based on control signals delivered to the control terminal of switching device  160 . In one example, if a voltage applied to the control terminal of switching device  160  is greater than or equal to a voltage threshold, switching device  160  may be activated, allowing switching device  160  to conduct electricity. Furthermore, switching device  160  may be deactivated when the voltage applied to the control terminal of switching device  160  is below the threshold voltage, thus preventing switching device  160  from conducting electricity. 
     Switching device  160  may include various material compounds, such as Silicon, Silicon Carbide, Gallium Nitride, or any other combination of one or more semiconductor materials. In some examples, silicon carbide switches may experience lower switching power losses. Improvements in magnetics and faster switching, such as Gallium Nitride switches, may allow switching device  160  to draw short bursts of current from power converter  120 . These higher frequency switching devices may require control signals to be sent with more precise timing, as compared to lower-frequency switching devices. 
     System  100  may control whether switching device  160  is activated based on an electrical current sensed by current sensor  162 . In some examples, current sensor  162  includes a current sensing resistor (not illustrated in  FIG. 1 ) and a current sensing amplifier (not illustrated in  FIG. 1 ). Ohm&#39;s law dictates that a voltage across a resistor is equal to a resistance of the resistor times a magnitude of a current across the resistor (V=I*R). As such, a current across the current sensing resistor is equal to a voltage across the current sensing resistor divided by a resistance value (in ohms (a)) of the current sensing resistor. The current sensing amplifier, in some cases, may output a current sensor signal correlated with a current across the current sensing resistor. As such, the current sensing amplifier may output the current sensor signal correlated with a current sensed by current sensor  162 . 
     Amplifier  170  may be configured to receive the current sensor signal from current sensor  162 . The current sensor signal may represent an electrical signal which includes a current sensor signal electrical voltage and a current sensor signal electrical current. In some examples, the current sensor signal electrical voltage is correlated with an electrical current sensed by current sensor  162 . In some examples, the current sensor signal electrical current is correlated with an electrical current sensed by current sensor  162 . In any case, the current sensor signal indicates a magnitude of the electrical current measured by current sensor  162 . 
     Amplifier  170  may receive a control signal. The control signal may represent an electrical signal which includes a control signal voltage and a control signal current. Based on the current sensor signal and the control signal, amplifier  170  may generate an amplifier signal for controlling whether switching device  160  is turned on or turned off. The control signal may include information indicative of one or more thresholds for the current sensor signal. For example, the control signal may include information indicative of a maximum current sensor signal value. The amplifier  170  may control the switching device  160  to be turned on when a current sensor signal value is greater than the maximum current sensor signal value. The amplifier  170  may control the switching device  160  to be turned off when a current sensor signal value is not greater than the maximum current sensor signal value. The maximum current sensor signal value may represent one or both of a maximum current sensor signal electrical voltage or a maximum current sensor signal electrical current. 
     In some examples, the control signal received by amplifier  170  may include information indicative of a lower-bound current sensor signal value and an upper-bound current sensor signal. Amplifier  170  may generate the amplifier signal in order to turn on switching device  160  when the current sensor signal increases to the upper-bound current sensor signal value, causing the current sensor signal to decrease from the upper-bound current sensor signal value. In other words, amplifier  170  may be configured to control switching device  160  to sink an undesired electrical current  161  during a current overshoot, thus preventing the current overshoot from damaging LEDs  150 . Amplifier  170  may generate the amplifier signal in order to turn off switching device  160  when the current sensor signal decreases to the lower-bound current sensor signal value. In other words, if the current sensor signal increases past a baseline value, indicating a current overshoot to LEDs  150 , amplifier  170  may generate the amplifier signal in order to maintain the current sensor signal between the lower-bound current sensor signal value and the upper-bound current sensor signal value. This, in turn, may ensure that the electrical current received by LEDs  150  during a current overshoot does not exceed a level which is harmful to LEDs  150 . 
     Additionally, or alternatively, amplifier  170  may also output the amplifier signal to power converter  120 . For example, power converter  120  may control an amount of electrical current output to LEDs  150 . Based on the amplifier signal, power converter  120  may adjust an amount of electrical current output from power converter  120  such that the amount of electrical current received by LEDs  150  does not damage LEDs  150 . For example, amplifier  170  may be configured to control power converter  120  to decrease an amount of electrical current output by power converter  120  in response to current sensor  162  detecting a current overshoot, thus preventing the current overshoot from damaging LEDs  150 . Amplifier  170  may output the amplifier signal in order to control a duty cycle of the one or more switching devices of power converter  120 . The amplifier signal may, in some cases, define on/off switching of one or more switching devices of power converter  120 , thereby causing power converter  120  to deliver the desired amount of electrical current to LEDs  150 . Increasing the duty cycle of the one or more switching devices may increase the electrical current delivered to LEDs  150 . Decreasing the duty cycle of the one or more switching devices may decrease the electrical current delivered to LEDs  150 . 
     Power converter  120  and/or capacitor  130  outputs electrical current  159 . When switching device  160  is activated, electrical current  159  may be split into the undesired electrical current  161  which flows through switching device  160  to ground and the desired electrical current  163  which flows through LEDs  150  to ground. During a current overshoot, a magnitude of electrical current  159  may be great enough to damage LEDs  150  if a full burden of electrical current  159  were to reach LEDs  150 . By turning on switching device  160 , amplifier  170  may split electrical current  159  into undesired electrical current  161  and desired electrical current  163 . This may cause undesired electrical current  161 , which is a portion of electrical current  159 , to flow through switching device  160  rather than flow through  150  and allow desired electrical current  163  to flow through LEDs  150 . While switching device  160  is turned on, a magnitude of desired electrical current  163  may be lower than a magnitude of electrical current  159  such that desired electrical current  163  does not cause damage to LEDs  150 . In other words, by preventing undesired electrical current  161  from reaching LEDs  150 , amplifier  170  may prevent a full force of electrical current  159  from damaging LEDs  160  during a current overshoot. 
     A current overshoot may occur when controller  112  outputs a control signal in order to short a path across a first set of LEDs of LEDs  150 , causing the first set of LEDs to turn off while a second set of LEDs of LEDs  150  remain turned on. By shorting the path across the first set of LEDs, controller  112  may remove the first set of LEDs from an electrical pathway between power converter  120  and ground. As such, shorting the path across the first set of LEDs may decrease a resistance of LEDs  150 , thus increasing the magnitude of electrical current  159  output from power converter  120  and/or capacitor  130 . Current sensor  162  may detect the current overshot by detecting the increase in electrical current  159 , and amplifier  170  may activate switching device  160  to sink the undesired electrical current  161 , preventing LEDs  150  from being damaged. In some examples, controller  112  may short a path across the first set of LEDs of LEDs  150  in response to receiving an instruction to toggle LEDs  150  from a high beam mode to a low beam mode. 
     A current overshoot may occur for one or more other reasons not described herein. For example, a current overshoot may represent any scenario in which electrical current  159  increases to a magnitude which may potentially harm LEDs  150 . Current sensor  162  may generate the current sensor signal in order to indicate a current overshoot, and amplifier  170  may control power converter  120  and/or switching device  160  in order to prevent the current overshoot from damaging LEDs  150 . 
       FIG. 2  is a circuit diagram illustrating a system  200  including a circuit for controlling power to a set of LEDs  250  using a switching device  260 , in accordance with one or more techniques of this disclosure. As illustrated in  FIG. 2 , system  200  includes power source  210 , power converter  220 , capacitor  230 , inductor  240 , LEDs  250 , current sensor  262 , and amplifier  270 . Power converter  220  includes switching devices  222 A- 222 D (collectively, “switching devices  222 ”) and inductor  224 . LEDs  250  include a first set of LEDs  252 , a second set of LEDs  254 , a first set of LED switching devices  256 , and a second set of LED switching devices  258 . Current sensor  262  includes current sensing resistor  264  and current sensing amplifier  266 . Amplifier control signal unit  272  may provide an amplifier control signal to amplifier  270 . Power source  210  may be an example of power source  110  of  FIG. 1 . Power converter  220  may be an example of power converter  120  of  FIG. 1 . Capacitor  230  may be an example of capacitor  130  of  FIG. 1 . Inductor  240  may be an example of inductor  140  of  FIG. 1 . LEDs  250  may be an example of LEDs  150  of  FIG. 1 . Switching device  260  may be an example of switching device  160  of  FIG. 1 . Current sensor  262  may be an example of current sensor  162  of  FIG. 1 . Amplifier  270  may be an example of amplifier  170  of  FIG. 1 . In some examples, system  200  may be configured to perform one or more techniques described herein without inductor  240 . 
     Power source  210  may supply an input signal to power converter  220 . Power converter  220  may include a switch/inductor unit that acts as a synchronous boost converter (e.g., an H-bridge). The H-bridge may be represented by switching devices  222  and inductor  224 . Each of switching devices  222  may, in some cases, include power switches such as, but not limited to, any type of FET including any combination of MOSFETs, BJTs, IGBTs, JFETs, HEMTs, or other elements that use voltage for control. Additionally, switching devices  222  may include n-type transistors, p-type transistors, and power transistors, or any combination thereof. In some examples, switching devices  222  include vertical transistors, lateral transistors, and/or horizontal transistors. In some examples, switching devices  222  include other analog devices such as diodes and/or thyristors. In some examples, switching devices  222  may operate as switches and/or as analog devices. 
     In some examples, each of switching devices  222  include three terminals: two load terminals and a control terminal. For MOSFET switches, each of switching devices  222  may include a drain terminal, a source terminal, and at least one gate terminal, where the control terminal is a gate terminal. For BJT switches, the control terminal may be a base terminal. Current may flow between the two load terminals of each of switching devices  222 , based on the voltage at the respective control terminal. Therefore, electrical current may flow across switching devices  222  based on control signals delivered to the respective control terminals of switching devices  222 . In one example, if a voltage applied to the control terminals of switching devices  222  is greater than or equal to a voltage threshold, switching devices  222  may be activated, allowing switching devices  222  to conduct electricity. Furthermore, switching devices  222  may be deactivated when the voltage applied to the respective control terminals of switching devices  222  is below the threshold voltage, thus preventing switching devices  222  from conducting electricity. A controller, e.g., controller  112  of  FIG. 1 , may be configured to independently control switching devices  222  such that one, a combination, all, or none of switching devices  222  may be activated at a point in time. 
     Switching devices  222  may include various material compounds, such as Silicon, Silicon Carbide, Gallium Nitride, or any other combination of one or more semiconductor materials. In some examples, silicon carbide switches may experience lower switching power losses. Improvements in magnetics and faster switching, such as Gallium Nitride switches, may allow switching devices  222  to draw short bursts of current from power source  210 . These higher frequency switching devices may require control signals (e.g., voltage signals delivered by a controller (not illustrated in  FIG. 2 ) to respective control terminals of switching devices  222 ) to be sent with more precise timing, as compared to lower-frequency switching devices. 
     Inductor  224  may represent a component of power converter  220  according to the example illustrated in  FIG. 2 . When inductor  224  is charged with a magnetic field and placed in series with power source  210  and LEDs  250 , the voltage across inductor  224  is configured to boost the magnitude of the output voltage delivered to LEDs  250 . 
     In some examples, a switch/inductor unit (e.g., switching devices  222  and inductor  224 ) may be configured to regulate the output voltage delivered to LEDs  250  using at least one operational mode including a boost mode. In the example illustrated in  FIG. 2 , switching devices  222  may include transistors, diodes, or other semiconductor elements. In boost mode, the switch/inductor unit may step up voltage and step down current from the input of power converter  220  to the output of power converter  220 . As such, power converter  220  may accept an input signal from power source  210  and generate a power converter output signal. The power converter output signal may include a power converter output voltage and a power converter output current, where the power converter output voltage is greater than a voltage of the input signal and the power converter output current is less than a current of the input signal when power converter  220  is in the boost mode. 
     In some examples, while the switch/inductor unit is in boost mode, switching device  222 A is activated, switching device  222 B is deactivated, and switching device  222 D alternates between being activated and being deactivated. When switching device  222 D is activated, an electrical current flows from power source  210  through switching device  222 A, inductor  224 , and switching device  222 D, charging inductor  224 . When switching device  222 D is deactivated, inductor  224  discharges and an electrical current flows from power source  210  through switching device  222 A, inductor  224 , and switching device  222 C, thus stepping up (e.g., boosting) an output voltage of the power converter output signal. Additionally, during boost mode, power converter  220  may step down a current of the power converter output signal. 
     Capacitor  230  may represent an output capacitor for power converter  220 . For example, capacitor  230  may charge to a charge level based on one or more cycles of power converter  220 . Power converter  220  may charge capacitor  230  based on a desired amount of electrical current for supply to LEDs  250 . For example, when LEDs  250  are operating in a high-light mode, it may be beneficial for LEDs  250  to receive a first amount of current. When LEDs  250  are operating in a low-light mode, it may be beneficial for LEDs  250  to receive a second amount of current which is lower than the first amount of current. A controller (e.g., controller  112  of  FIG. 1 ) may switch LEDs  250  from the high-light mode to the low-light mode. This may cause a temporary surge (e.g., “overshoot”) in the electrical current  259  output from power converter  220  and/or capacitor  230 . Additionally, or alternatively, one or more other factors may cause an overshoot in the electrical current  259 . 
     Current sensor  262  may be configured to generate a current sensor signal which indicates a magnitude of electrical current  259 . That is, current sensor  262  may be configured to generate the current sensor signal to indicate the magnitude of the electrical current flowing from node  257  to node  265 . In some examples, current sensor  262  includes current sensing resistor  264  and current sensing amplifier  266 . Ohm&#39;s law defines that a voltage across a resistor is equal to a resistance of the resistor times a magnitude of a current across the resistor (V=I*R). As such, a current across current sensing resistor  264  is equal to a voltage across current sensing resistor  264  divided by a resistance value (in ohms (a)) of current sensing resistor  264 . Current sensing amplifier  266 , in some cases, may output a current sensor signal correlated with a current across current sensing resistor  264 . As such, current sensing amplifier  266  may output the current sensor signal correlated with a current sensed by current sensor  162 . 
     Current sensor  262  outputs the current sensor signal to amplifier  270 . Additionally, amplifier  270  receives a control signal from control signal unit  272 . In turn, amplifier  270  generates an amplifier signal for output to a control terminal of switching device  260 . In some examples, amplifier  270  may generate the amplifier signal based on whether a magnitude of the current sensor signal is greater than or equal to a maximum parameter value indicated by the control signal. If the magnitude of the current sensor signal is greater than or equal to the maximum parameter value, amplifier  270  may generate the amplifier signal to turn on switching device  260 . If the magnitude of the current sensor signal is not greater than or equal to the maximum parameter value, amplifier  270  may generate the amplifier signal to turn off switching device  260 . 
     When switching device  260  is turned on, electrical current  259  may be divided into undesired electrical current  261  which flows through switching device  260  and desired electrical current  263  which flows through LEDs  250 . In other words, switching device  260  “sinks” the undesired electrical current  261  so that the undesired electrical current  261  does not reach LEDs  250 . When switching device  260  is turned off, a magnitude of the undesired electrical current  261  may be zero or near-zero. This means that a magnitude of desired electrical current  263  may be the same as the magnitude of electrical current  259  when switching device  260  is turned off. 
     Amplifier  270  may, in some cases, output the amplifier signal to power converter  220 . As such, amplifier  270  may control one or more aspects of the operation of power converter  220 . For example, the amplifier signal may control a duty cycle of one or more of switching devices  222  of power converter  220 , thus controlling a magnitude of electrical current  259 . For example, decreasing a duty cycle of one or more of switching devices  222  may cause the magnitude of electrical current  259  to decrease and increasing the duty cycle of one or more of switching devices  222  may cause the magnitude of electrical current  259  to increase. In some examples, the amplifier signal may control a switching mode (e.g., boost mode or buck mode) which power converter  220  operates according to. In some examples, the amplifier signal may control one or more other aspect of the operation of power converter  220 . 
     In some examples, a controller may short the first set of LEDs  252  by turning on the first set of LED switching devices  256 . In some examples, the controller may short the second set of LEDs  254  by turning on the second set of LED switching devices  258 . Shorting one or both of the first set of LEDs  252  or the second set of LEDs  254  may cause an overshoot in electrical current  259 . Current sensor  262  may generate the current sensor signal in order to indicate the current overshoot, and amplifier  270 —may sink the undesired electrical current  161  in response to receiving the current sensor signal indicating the current overshoot, preventing the current overshoot from damaging LEDs  250 . In some examples, the controller shorts the path across the first set of LEDs  252  in response to receiving an instruction to toggle the string of LEDs from a high beam mode to a low beam mode. 
       FIG. 3  is a circuit diagram illustrating a system  300  including a circuit for controlling power to a set of LEDs  350  by controlling a switching device  260  and controlling a power converter  320 , in accordance with one or more techniques of this disclosure. As illustrated in  FIG. 3 , system  300  includes power source  310 , power converter  320 , capacitor  330 , inductor  340 , LEDs  350 , current sensor  362 , and amplifier  370 . Power converter  320  includes switching devices  322 A- 322 D (collectively, “switching devices  322 ”) and inductor  324 . LEDs  350  include a first set of LEDs  352 , a second set of LEDs  354 , a first set of LED switching devices  356 , and a second set of LED switching devices  358 . Current sensor  362  includes current sensing resistor  364  and current sensing amplifier  366 . Amplifier control signal unit  372  may provide an amplifier control signal to amplifier  370 . Power source  310  may be an example of power source  110  of  FIG. 1 . Power converter  320  may be an example of power converter  120  of  FIG. 1 . Capacitor  330  may be an example of capacitor  130  of  FIG. 1 . Inductor  340  may be an example of inductor  140  of  FIG. 1 . LEDs  350  may be an example of LEDs  150  of  FIG. 1 . Switching device  360  may be an example of switching device  160  of  FIG. 1 . Current sensor  362  may be an example of current sensor  162  of  FIG. 1 . Amplifier  370  may be an example of amplifier  170  of  FIG. 1 . In some examples, system  300  may be configured to perform one or more techniques described herein without inductor  340 . 
     The system  300  of  FIG. 3  may be substantially the same as the system  200  of  FIG. 2 , except that switching device  360 , current sensor  362 , amplifier  370 , and amplifier control signal unit  372  are placed in a configuration such that node  365  emits undesired electrical current  361  which flows through switching device  360  and emits desired electrical current  363  which is sensed by current sensor  362 . System  200  of  FIG. 2 , on the other hand, includes a current sensor  262  which senses an electrical current  259  flowing into a node  265 , where undesired electrical current  261  and desired electrical current  263  flow from node  265 . 
     In some examples, power converter  320  and capacitor  330  may cause node  357  to emit electrical current  359 . Electrical current  359  may flow through an electrical conductor from node  357  to node  365 . In some examples, node  357  and node  365  may be classified as one electrical node, since there are no electrical circuit elements between node  357  and node  365 , meaning that node  357  and node  365  have the same voltage. In some examples, node  365  emits undesired electrical current  361  and desired electrical current  363  when switching device  360  is turned on, meaning that switching device  360  is configured to create an electrical pathway from node  365  to ground when switching device  360  is turned on, causing electrical current  359  to split into undesired electrical current  361  and desired electrical current  363 . When switching device  360  is turned off, there may be no electrical pathway from node  365  to ground through switching device  360 . This means that a magnitude of desired electrical current  363  may be substantially the same as a magnitude of electrical current  359  and a magnitude of undesired electrical current  361  may be zero when switching device  360  is turned off. 
     Current sensor  362  may be configured to generate a current sensor signal which indicates a magnitude of desired electrical current  363 . That is, current sensor  362  may be configured to generate the current sensor signal to indicate the magnitude of the electrical current flowing from node  365  to inductor  340 . In some examples, current sensor  362  includes current sensing resistor  364  and current sensing amplifier  366 . Ohm&#39;s law dictates that a voltage across a resistor is equal to a resistance of the resistor times a magnitude of a current across the resistor (V=I*R). As such, a current across current sensing resistor  364  is equal to a voltage across current sensing resistor  364  divided by a resistance value (in ohms (a)) of current sensing resistor  364 . Current sensing amplifier  366 , in some cases, may output a current sensor signal correlated with a current across current sensing resistor  364 . As such, current sensing amplifier  366  may output the current sensor signal correlated with a current sensed by current sensor  362 . 
     Current sensor  362  outputs the current sensor signal to amplifier  370 . Additionally, amplifier  370  receives a control signal from control signal unit  372 . In turn, amplifier  370  generates an amplifier signal for output to a control terminal of switching device  360 . Additionally, amplifier  370  outputs the amplified signal to power converter  320 . In some examples, amplifier  370  may generate the amplifier signal based on a comparison of the current sensor signal to one or more thresholds indicated by the control signal. For example, the control signal may include an upper-bound overshoot current threshold and a lower-bound overshoot current threshold. 
     When a magnitude of the current sensor signal generated by current sensor  362  increases to the upper-bound overshoot current threshold, amplifier  370  may generate the amplifier signal to turn on switching device  360 , thus sinking undesired electrical current  361  to ground and preventing electrical current  359  from damaging LEDs  350  when electrical current  359  represents an overshoot current. By turning on switching device  360  and sinking the undesired electrical current  361 , amplifier  370  may cause desired electrical current  363  to decrease, thus decreasing the current sensor signal generated by current sensor  362 . When the current sensor signal decreases to the lower-bound overshoot current threshold from the upper-bound overshoot current threshold, amplifier  370  may generate the amplifier signal in order to turn off switching device  360 . This means that there is no longer an electrical pathway from node  365  to ground through switching device  360 , and desired electrical current  363  increases, causing the current sensor signal to increase. In some examples, the current sensor signal increases from the lower-bound overshoot current threshold to the upper-bound overshoot current threshold in response to amplifier  370  turning off the switching device  360 . Responsive to the current sensor signal increasing from the lower-bound overshoot current threshold to the upper-bound overshoot current threshold, amplifier  370  may generate the amplifier signal to turn on switching device  360  once again, causing desired electrical current  363  to decrease and preventing electrical current  359  from damaging LEDs  350  when electrical current  359  represents an overshoot current. 
     In some examples, electrical current  359  settles to a baseline electrical current value following an overshoot of electrical current  359 . When electrical current  359  represents a baseline electrical current value, a magnitude of desired electrical current  363  may be low enough such that current sensor  362  and amplifier  370  do not turn on switching device  360  to sink undesired electrical current  361 . 
     Amplifier  370  may, in some cases, output the amplifier signal to power converter  320 . As such, amplifier  370  may control one or more aspects of the operation of power converter  320 . For example, the amplifier signal may control a duty cycle of one or more of switching devices  322  of power converter  320 , thus controlling a magnitude of electrical current  359 . For example, decreasing a duty cycle of one or more of switching devices  322  may cause the magnitude of electrical current  359  to decrease and increasing the duty cycle of one or more of switching devices  322  may cause the magnitude of electrical current  359  to increase. In some examples, the amplifier signal may control a switching mode (e.g., boost mode or buck mode) which power converter  320  operates according to. In some examples, the amplifier signal may control one or more other aspect of the operation of power converter  320 . 
     Desired electrical current  363 ′ may be substantially the same as desired electrical current  363  except that desired electrical current  363 ′ represents the current on an opposite side of inductor  340  as desired electrical current  363 . When inductor  340  is fully charged, a magnitude of the desired electrical current  363  is the same as a magnitude of the desired electrical current  363 ′. When desired electrical current  363  is changing, however, the magnitude of the desired electrical current  363  may be different than the magnitude of the desired electrical current  363 ′, since inductor  340  resists change in current. As described above, system  300  may be configured to operate without inductor  340  between current sensor  362  and LEDs  350 . When inductor  340  is not located between current sensor  362  and LEDs  350 , electrical current  363 ′ may be equal to electrical current  363 . 
       FIG. 4  is a circuit diagram illustrating a system  400  including a circuit for controlling power to a set of LEDs  450  by controlling a power converter  420 , in accordance with one or more techniques of this disclosure. As illustrated in  FIG. 4 , system  400  includes power source  410 , power converter  420 , capacitor  430 , inductor  440 , LEDs  450 , current sensor  462 , and amplifier  470 . Power converter  420  includes switching devices  422 A- 422 D (collectively, “switching devices  422 ”) and inductor  424 . LEDs  450  include a first set of LEDs  452 , a second set of LEDs  454 , a first set of LED switching devices  456 , and a second set of LED switching devices  458 . Current sensor  462  includes current sensing resistor  464  and current sensing amplifier  466 . Amplifier control signal unit  472  may provide an amplifier control signal to amplifier  470 . Power source  410  may be an example of power source  110  of  FIG. 1 . Power converter  420  may be an example of power converter  120  of  FIG. 1 . Capacitor  430  may be an example of capacitor  130  of  FIG. 1 . Inductor  440  may be an example of inductor  140  of  FIG. 1 . LEDs  450  may be an example of LEDs  150  of  FIG. 1 . Current sensor  462  may be an example of current sensor  162  of  FIG. 1 . Amplifier  470  may be an example of amplifier  170  of  FIG. 1 . In some examples, system  400  may be configured to perform one or more techniques described herein without inductor  440 . 
     The system  400  of  FIG. 4  may be substantially the same as the system  300  of  FIG. 3 , except that current sensor  462 , amplifier  470 , and amplifier control signal unit  472  are placed in a configuration such that node  457  emits desired electrical current  463  which is sensed by current sensor  462 , causing amplifier  470  to generate an amplifier signal in order to control power converter  420 . System  300  of  FIG. 3 , on the other hand, includes a current sensor  362  which senses desired electrical current  363 , causing amplifier  370  to control a switching device  360 , which is separate from power converter  320 . 
     In some examples, power converter  420  charges capacitor  430 . When capacitor  430  discharges, capacitor  430  may emit electrical current  459  to node  457 . In some examples, when power converter  420  includes an electrical pathway to ground, power converter  420  may sink an unwanted electrical current  461 . For example, an electrical pathway may exist between capacitor  430  and ground through switching device  422 C and switching device  422 D when switching device  422 C and switching device  422 D are turned on. 
     Current sensor  462  may be configured to generate a current sensor signal which indicates a magnitude of desired electrical current  463 . That is, current sensor  462  may be configured to generate the current sensor signal to indicate the magnitude of the electrical current flowing from node  457  to inductor  440 . In some examples, current sensor  462  includes current sensing resistor  464  and current sensing amplifier  466 . Ohm&#39;s law dictates that a voltage across a resistor is equal to a resistance of the resistor times a magnitude of a current across the resistor (V=I*R). As such, a current across current sensing resistor  464  is equal to a voltage across current sensing resistor  464  divided by a resistance value (in ohms (a)) of current sensing resistor  464 . Current sensing amplifier  466 , in some cases, may output a current sensor signal correlated with a current across current sensing resistor  464 . As such, current sensing amplifier  466  may output the current sensor signal correlated with a current sensed by current sensor  462 . 
     Current sensor  462  outputs the current sensor signal to amplifier  470 . Additionally, amplifier  470  receives a control signal from control signal unit  472 . In turn, amplifier  470  generates an amplifier signal for output to power converter  420 . Additionally, amplifier  470  outputs the amplified signal to power converter  420 . In some examples, amplifier  470  may generate the amplifier signal based on a comparison of the current sensor signal to one or more thresholds indicated by the control signal. For example, the control signal may include an upper-bound overshoot current threshold and a lower-bound overshoot current threshold. 
     When a magnitude of the current sensor signal generated by current sensor  462  increases to the upper-bound overshoot current threshold, amplifier  470  may generate the amplifier signal to create an electrical pathway through power converter  420 , thus sinking undesired electrical current  461  to ground and preventing electrical current  459  from damaging LEDs  450  when electrical current  459  represents an overshoot current. By sinking the undesired electrical current  461 , amplifier  470  may cause desired electrical current  463  to decrease, thus decreasing the current sensor signal generated by current sensor  462 . When the current sensor signal decreases to the lower-bound overshoot current threshold from the upper-bound overshoot current threshold, amplifier  470  may generate the amplifier signal in order to break the electrical pathway through power converter  420 . This means that desired electrical current  463  increases, causing the current sensor signal to increase. In some examples, the current sensor signal increases from the lower-bound overshoot current threshold to the upper-bound overshoot current threshold in response to amplifier  470  cutting off the electrical pathway through power converter  420 . Responsive to the current sensor signal increasing from the lower-bound overshoot current threshold to the upper-bound overshoot current threshold, amplifier  470  may generate the amplifier signal to once again create the electrical pathway through power converter  420 , causing desired electrical current  463  to decrease and preventing electrical current  459  from damaging LEDs  450  when electrical current  459  represents an overshoot current. 
     Desired electrical current  463 ′ may be substantially the same as desired electrical current  463  except that desired electrical current  463 ′ represents the current on an opposite side of inductor  440  as desired electrical current  463 . When inductor  440  is fully charged, a magnitude of the desired electrical current  463  is the same as a magnitude of the desired electrical current  463 ′. When desired electrical current  463  is changing, however, the magnitude of the desired electrical current  463  may be different than the magnitude of the desired electrical current  463 ′, since inductor  440  resists change in current. As described above, system  400  may be configured to operate without inductor  440  between current sensor  462  and LEDs  450 . When inductor  440  is not located between current sensor  462  and LEDs  450 , electrical current  463 ′ may be equal to electrical current  463 . 
       FIG. 5  is a graph  500  illustrating a switching device mode plot  510 , a current sensor signal plot  520 , and an undesired current plot  530 , in accordance with one or more techniques of this disclosure.  FIG. 5  is described with respect to system  200  of  FIG. 2 . However, the techniques of  FIG. 5  may be performed by different components of system  200  or by additional or alternative systems or devices. 
     Device mode plot  510  may indicate that switching device  260  is turned off when switching device mode plot  510  is at level  512 . Device mode plot  510  may indicate that switching device  260  is turned on when switching device mode plot  510  is at level  514 . As seen in  FIG. 5 , device mode plot  510  transitions from level  512  to level  514  at time  552  and transitions from level  514  to level  512  at time  554 . This means that switching device  260  turns on at time  552  and turns off at time  554 . In some examples, a control terminal switching device  260  receives an amplifier signal from amplifier  270  which controls whether switching device  260  is turned on or turned off. When switching device  260  is turned on, switching device  260  may sink an undesired electrical current  261 , thus preventing an electrical current  259  from damaging LEDs  250 . 
     Current sensor signal plot  520  may, in some examples, may indicate a voltage of the current sensor signal of the current sensor signal generated by current sensor  262 . In some examples, amplifier  270  may receive a control signal which includes a current sensor signal threshold  524 . In some examples, the current sensor signal threshold is a predetermined percentage above a baseline current sensor signal value  522 . As seen in  FIG. 5 , when current sensor signal plot  520  increases to the current sensor signal threshold  524 , amplifier  270  may generate the amplifier signal to turn on switching device  260 , thus sinking undesired electrical current  261 . When current sensor signal plot  520  decreases from the current sensor signal threshold  524 , amplifier  270  may generate the amplifier signal to turn off switching device  260 . 
     Undesired current plot  530  may indicate a magnitude of the undesired electrical current  261  flowing through switching device  260 . In some examples, when switching device  260  is turned off, undesired current plot  530  indicates that undesired electrical current  261  is at zero. Level  532  of undesired current plot  530  indicates that the magnitude of undesired electrical current  261  is zero. As seen in  FIG. 5 , undesired current plot  530  is greater than zero between time  552  and second time  554  when switching device  260  is turned on, meaning that switching device  260  is sinking current. 
       FIG. 6  is a graph  600  illustrating a switching device mode plot  610 , a current sensor signal plot  620 , and an undesired current plot  630 , in accordance with one or more techniques of this disclosure.  FIG. 6  is described with respect to system  300  of  FIG. 3 . However, the techniques of  FIG. 6  may be performed by different components of system  300  or by additional or alternative systems or devices. 
     Device mode plot  610  may indicate that switching device  360  is turned off when switching device mode plot  610  is at level  612 . Device mode plot  610  may indicate that switching device  360  is turned on when switching device mode plot  610  is at level  612 . As seen in  FIG. 6 , device mode plot  610  transitions from level  612  to level  614  at time  652  and transitions from level  614  to level  612  at time  654 . This means that switching device  360  turns on at time  652  and turns off at time  654 . Additionally, device mode plot  610  transitions from level  612  to level  614  at time  656  and transitions from level  614  to level  612  at time  658 , meaning that switching device  360  turns on at time  656  and turns off at time  658 . In some examples, a control terminal switching device  360  receives an amplifier signal from amplifier  370  which controls whether switching device  360  is turned on or turned off. When switching device  360  is turned on, switching device  360  may sink an undesired electrical current  361 , thus preventing an electrical current  359  from damaging LEDs  350 . 
     Current sensor signal plot  620  may, in some examples, may indicate a voltage of the current sensor signal of the current sensor signal generated by current sensor  362 . In some examples, amplifier  370  may receive a control signal which includes a lower-bound current sensor signal threshold  624  and an upper-bound current sensor signal threshold  626 . In some examples, the lower-bound current sensor signal threshold  624  is a first predetermined percentage above a baseline current sensor signal value  622  and the upper-bound current sensor signal threshold  626  is a second predetermined percentage above the baseline current sensor signal value  622 . As seen in  FIG. 6 , when current sensor signal plot  620  increases to the upper-bound current sensor signal threshold  626  at time  652 , amplifier  370  may generate the amplifier signal to turn on switching device  360 , thus sinking undesired electrical current  361 . This may cause current sensor signal plot  620  to decrease from the upper-bound current sensor signal threshold  626  to the lower-bound current sensor signal threshold  624  between time  652  and time  654 . 
     When current sensor signal plot  620  decreases from the upper-bound current sensor signal threshold  626  to the lower-bound current sensor signal threshold  624 , amplifier  370  may generate the amplifier signal to turn off switching device  360  at time  654 . This may cause the electrical current sensed by current sensor  362  to increase from time  654  to time  656 , since switching device  360  does not sink undesired electrical current  361  while switching device  360  is turned off. As seen in  FIG. 6 , the current sensor signal plot  620  increases from lower-bound current sensor signal threshold  624  to upper-bound current sensor signal threshold  626  between time  654  and time  656 . When current sensor signal plot  620  increases to the upper-bound current sensor signal threshold  626  at time  656 , amplifier  370  may generate the amplifier signal to turn on switching device  360 , thus sinking undesired electrical current  361 . This may cause current sensor signal plot  620  to decrease from the upper-bound current sensor signal threshold  626  to the lower-bound current sensor signal threshold  624  between time  656  and time  658 . When current sensor signal plot  620  decreases from the upper-bound current sensor signal threshold  626  to the lower-bound current sensor signal threshold  624 , amplifier  370  may generate the amplifier signal to turn off switching device  360  at time  658 . At time  658 , a current overshoot may be over, and current sensor signal plot  620  may continue to decrease to baseline current sensor signal value  622  following time  658 . 
     Undesired current plot  630  may indicate a magnitude of the undesired electrical current  361  flowing through switching device  360 . In some examples, when switching device  360  is turned off, undesired current plot  630  indicates that undesired electrical current  361  is at zero. Level  632  of undesired current plot  630  indicates that the magnitude of undesired electrical current  361  is zero. Level  634  of undesired current plot  630  indicates that the magnitude of undesired electrical current  361  is greater than zero. As seen in  FIG. 6 , undesired current plot  630  is greater than zero between time  652  and time  654  and between time  656  and time  658  when switching device  360  is turned on, meaning that switching device  360  is sinking current. Additionally, undesired current plot  630  is zero before time  652 , between time  654  and time  656 , and after time  658  when switching device  360  is turned off, meaning that switching device  360  is not sinking current. 
       FIG. 7  is a flow diagram illustrating an example operation for controlling a switching device to sink electrical current during an electrical current overshoot, in accordance with one or more techniques of this disclosure.  FIG. 7  is described with respect to system  100  of  FIG. 1 . However, the techniques of  FIG. 7  may be performed by different components of system  100  or by additional or alternative systems. 
     Current sensor  162  generates a current sensor signal which indicates a magnitude of an electrical current ( 702 ). In some examples, the current sensor signal indicates a magnitude of an electrical current, where at least a portion of the electrical current travels to LEDs  150 . For example, the current sensor  162  may be configured to detect an electrical current overshoot that is potentially damaging to the LEDs. Amplifier  170  receives the current sensor signal ( 704 ) from the current sensor  162 . Additionally, amplifier  170  receives a control signal ( 706 ). In some examples, the control signal includes one or more current sensor signal thresholds. 
     Amplifier  170  may compare the current sensor signal with the one or more current sensor signal thresholds in order to control switching device  160 . Amplifier  170  is configured to generate the amplifier signal based on the current sensor signal and the control signal ( 708 ) and output the amplifier signal to switching device  160  in order to control an electrical current through LEDs  150  ( 710 ). For example, when the amplifier signal is at a first level, switching device  160  may turn on and when the amplifier signal is at a second level, switching device  160  may turn off. Power converter  120  and/or capacitor  130  outputs electrical current  159 . When switching device  160  is activated, electrical current  159  may be split into the undesired electrical current  161  which flows through switching device  160  to ground and the desired electrical current  163  which flows through LEDs  150  to ground. 
     During a current overshoot, a magnitude of electrical current  159  may be great enough to damage LEDs  150  if a full burden of electrical current  159  were to reach LEDs  150 . By turning on switching device  160 , amplifier  170  may split electrical current  159  into undesired electrical current  161  and desired electrical current  163 . This may cause undesired electrical current  161 , which is a portion of electrical current  159 , to flow through switching device  160  rather than flow through  150  and allow desired electrical current  163  to flow through LEDs  150 . While switching device  160  is turned on, a magnitude of desired electrical current  163  may be lower than a magnitude of electrical current  159  such that desired electrical current  163  does not cause damage to LEDs  150 . In other words, by preventing undesired electrical current  161  from reaching LEDs  150 , amplifier  170  may prevent a full force of electrical current  159  from damaging LEDs  160  during a current overshoot. 
     The techniques described in this disclosure may be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, various aspects of the described techniques may be implemented within one or more processors, including one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. The term “processor” or “processing circuitry” may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry. A control unit including hardware may also perform one or more of the techniques of this disclosure. 
     Such hardware, software, and firmware may be implemented within the same device or within separate devices to support the various techniques described in this disclosure. In addition, any of the described units, modules or components may be implemented together or separately as discrete but interoperable logic devices. Depiction of different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be realized by separate hardware, firmware, or software components. Rather, functionality associated with one or more modules or units may be performed by separate hardware, firmware, or software components, or integrated within common or separate hardware, firmware, or software components. 
     The following numbered examples demonstrate one or more aspects of the disclosure. 
     Example 1. A circuit configured to control power delivered to a string of light-emitting diodes (LEDs), the circuit including a power converter configured to generate an electrical current, a switching device, and a sensor. The sensor is configured to compare a magnitude of the electrical current to a threshold. In response to the magnitude exceeding the threshold, the sensor is configured to cause the switching device to turn on in order to sink a portion of the electrical current to prevent the magnitude of the electrical current from exceeding the threshold. When the switching device is turned on, the electrical current is divided into an undesired electrical current that flows across the switching device and a desired electrical current that flows to the string of LEDs. 
     Example 2. The circuit of example 1, wherein when the switching device is turned on, the undesired electrical current flows across the switching device without flowing through the string of LEDs. 
     Example 3. The circuit of any of examples 1-2, wherein when the switching device is turned off, the electrical current generated by the power converter corresponds to the desired electrical current that flows to the string of LEDs to drive the LEDs without any of the undesired electrical current flowing through the switching device. 
     Example 4. The circuit of any of examples 1-3, wherein the sensor is configured to generate a first electrical signal to indicate a magnitude of at least a portion of the electrical current, and wherein the circuit further includes an amplifier configured to: receive the first electrical signal; receive a second electrical signal; generate, based on the first electrical signal and the second electrical signal, a third electrical signal; and output the third electrical signal to the switching device in order to control whether the switching device is turned on or turned off. 
     Example 5. The circuit of any of examples 1-4, wherein the amplifier is configured to generate the first electrical signal to indicate the magnitude of the desired electrical current which flows from the power source to the string of LEDs, wherein the second electrical signal includes a lower-bound voltage value and an upper-bound voltage value, and wherein the amplifier is configured to: generate the third electrical signal in order to turn on the switching device when the first electrical signal increases to the upper-bound voltage value, causing the first electrical signal to decrease from the upper-bound voltage value; and generate the third electrical signal in order to turn off the switching device when the first electrical signal decreases to the lower-bound voltage value. 
     Example 6. The circuit of any of examples 1-5, wherein the sensor is configured to generate the first electrical signal to indicate the magnitude of electrical current generated by the power converter, wherein the second electrical signal includes a maximum voltage value, and wherein the amplifier is configured to: generate the third electrical signal in order to turn on the switching device when the first voltage value increases to the maximum voltage value; and generate the third electrical signal in order to turn off the switching device when the first voltage value decreases from the maximum voltage value. 
     Example 7. The circuit of any of examples 1-6, wherein the amplifier is configured to receive the second electrical signal from the undesired electrical current which flows across the switching device. 
     Example 8. The circuit of any of examples 1-7, wherein the power converter includes the switching device, wherein to output the third electrical signal to the switching device in order to control whether the switching device is turned on or turned off, the amplifier is configured to output the third electrical signal to the power converter, preventing the magnitude of the desired electrical current from exceeding the threshold. 
     Example 9. The circuit of any of examples 1-8, wherein by outputting the third electrical signal to the power converter, the amplifier is configured to cause the power converter to change a duty cycle of the switching device in order to prevent the magnitude of the desired electrical current from exceeding the threshold. 
     Example 10. The circuit of any of examples 1-9, further including a controller configured to: output a control signal in order to short a path across a first set of LEDs of the string of LEDs, causing the first set of LEDs to turn off while a second set of LEDs of the string of LEDs remain turned on, wherein creating the short path across the first set of LEDs decreases a resistance of the string of LEDs, thus increasing the magnitude of the desired electrical current flowing to the string of LEDs. 
     Example 11. The circuit of any of examples 1-10, wherein the controller outputs the control signal in order to short the path across the first set of LEDs in response to receiving an instruction to toggle the string of LEDs from a high beam (HB) mode to a low beam (LB) mode. 
     Example 12. A method for controlling power delivered to a string of light-emitting diodes (LEDs), the method including generating, by a power converter, an electrical current and comparing, by a sensor, a magnitude of the electrical current to a threshold. In response to the magnitude exceeding the threshold, the method further includes causing, by the sensor, a switching device to turn on in order to sink a portion of the electrical current to prevent the magnitude of the electrical current from exceeding the threshold. When the switching device is turned on, the electrical current is divided into an undesired electrical current that flows across the switching device and a desired electrical current that flows to the string of LEDs. 
     Example 13. The method of example 12, wherein when the switching device is turned on, the undesired electrical current flows across the switching device without flowing through the string of LEDs. 
     Example 14. The method of any of examples 12-13, wherein when the switching device is turned off, the electrical current generated by the power converter corresponds to the desired electrical current that flows to the string of LEDs to drive the LEDs without any of the undesired electrical current flowing through the switching device. 
     Example 15. The method of any of examples 12-14, further including: generating, by the sensor, a first electrical signal to indicate a magnitude of at least a portion of the electrical current; receiving, by an amplifier, the first electrical signal; receiving, by the amplifier, a second electrical signal; generating, by the amplifier based on the first electrical signal and the second electrical signal, a third electrical signal; and outputting, by the amplifier, the third electrical signal to the switching device in order to control whether the switching device is turned on or turned off. 
     Example 16. The method of any of examples 12-15, further including: generating, by the amplifier, the first electrical signal to indicate the magnitude of the desired electrical current which flows from the power source to the string of LEDs, wherein the second electrical signal includes a lower-bound voltage value and an upper-bound voltage value; generating, by the amplifier, the third electrical signal in order to turn on the switching device when the first electrical signal increases to the upper-bound voltage value, causing the first electrical signal to decrease from the upper-bound voltage value; and generating, by the amplifier, the third electrical signal in order to turn off the switching device when the first electrical signal decreases to the lower-bound voltage value. 
     Example 17. The method of any of examples 12-16, further including: generating, by the sensor, the first electrical signal to indicate the magnitude of electrical current generated by the power converter, wherein the second electrical signal includes a maximum voltage value; generating, by the amplifier, the third electrical signal in order to turn on the switching device when the first voltage value increases to the maximum voltage value; and generating, by the amplifier, the third electrical signal in order to turn off the switching device when the first voltage value decreases from the maximum voltage value. 
     Example 18. The method of any of examples 12-17, further including receiving, by the amplifier, the second electrical signal from the undesired electrical current which flows across the switching device. 
     Example 19. The method of any of examples 12-18, wherein the power converter includes the switching device, wherein outputting the third electrical signal to the switching device in order to control whether the switching device is turned on or turned off includes outputting, by the amplifier, the third electrical signal to the power converter, preventing the magnitude of the desired electrical current from exceeding the threshold. 
     Example 20. The method of any of examples 12-19, wherein by outputting the third electrical signal to the power converter, the amplifier is configured to cause the power converter to change a duty cycle of the switching device in order to prevent the magnitude of the desired electrical current from exceeding the threshold. 
     Example 21. The method of any of examples 12-20, further including: outputting, by a controller, a control signal in order to short a path across a first set of LEDs of the string of LEDs, causing the first set of LEDs to turn off while a second set of LEDs of the string of LEDs remain turned on, wherein creating the short path across the first set of LEDs decreases a resistance of the string of LEDs, thus increasing the magnitude of the desired electrical current flowing to the string of LEDs. 
     Example 22. The method of any of examples 12-21, wherein the controller outputs the control signal in order to short the path across the first set of LEDs in response to receiving an instruction to toggle the string of LEDs from a high beam (HB) mode to a low beam (LB) mode. 
     Example 23. A system including: a string of light-emitting diodes (LEDs); a power converter configured to generate an electrical current; a switching device; and a sensor. The sensor is configured to compare a magnitude of the electrical current to a threshold. In response to the magnitude exceeding the threshold, the sensor is configured to cause the switching device to turn on in order to sink a portion of the electrical current to prevent the magnitude of the electrical current from exceeding the threshold. When the switching device is turned on, the electrical current is divided into an undesired electrical current that flows across the switching device and a desired electrical current that flows to the string of LEDs. 
     Various examples of the disclosure have been described. These and other examples are within the scope of the following claims.