Temperature controller for direct mounting to the object to be controlled

An integrated solid-state temperature controller that is mountable to an object the temperature of which is controlled by the solid-state temperature controller, or is mountable in a space in which the temperature is controlled by the solid-state temperature controller. The solid-state temperature controller able to withstand and continue to operate in extremes of temperatures at which the object or space is controlled, and able to withstand and continue to operate in extremes of temperatures of the object or space when the temperature is not being controlled.

BACKGROUND

This disclosure is directed to a device and methods for a temperature controller that is mounted directly to the object whose temperature the device and methods are controlling.

There are numerous applications in which the temperature of an object or a space must be controlled within a close tolerance. Conventionally, control is performed by a controller connected to a temperature measuring device or temperature sensor. A comparison is made generally between a measured or sensed temperature and a preset temperature. The controller then controls power to a heater or cooler to control the temperature of the object or space to within a predetermined limited range from the set temperature.

One conventional method to achieve temperature control from an attached controller involves applying a bimetallic strip at least as the sensor element.FIG. 1shows a conventional bimetallic strip controller. The bimetallic sensor1is mounted on an object3. A heater or cooler2is provided to heat or cool the object3. A power supply4provides power to the heater2. The bimetallic strip controller1includes a bimetallic strip5, contacts6and an adjustment mechanism7. The bimetallic strip may also be mounted within a space where the temperature is to be controlled.

As the temperature changes, the bimetallic strip5will bend or straighten depending on the temperature of the bimetallic strip5. Bimetallic strip temperature sensors are designed so that the bimetallic strip5is bistable, and has two stable states. Depending upon the temperature and the inherent stress caused by that temperature, the bimetallic strip5will alternate between the two states. The advantage of the bistablity is that a deadband forms due to hysterisis and the state does not alternate back and forth at a single temperature set point. The state will change from a first state to a second state at a first temperature, but change from the second state back to the first state at a slightly different second temperature. This deadband between the first and second temperatures means that when the object or space is maintained in a temperature range near the set temperature such that the heater or cooler is not being constantly switched on and off.

Assuming that the object3must be held above ambient temperature the heater or cooler2is a heater. The bimetallic strip5is in close contact with the object3and has approximately the same temperature as object3. When the temperature of object3is below a first preset temperature that is, a little above the desired temperature, defined by adjustment mechanism7, the bimetallic strip is stressed by the low temperature into the first stable state, so that contacts6are connected. Power flows from the voltage source4to the heater2. As a result, the object3warms up along with the bimetallic strip5. When the temperature reaches the first preset temperature, the bimetallic strip is stressed by the change in temperature and changed to the second stable state in which the contacts6are broken. Power is then disconnected from the heater2and the object3will cool until the temperature two a second preset temperature, a little below the desired temperature. At which point the bimetallic strip will change back to the first stable state in which contacts6are connected and the heater2will begin to heat object3once more. This process continues keeping the object3within the deadband temperature range, around the desired set temperature.

The adjustment mechanism7allows the adjustment of the set temperature and the deadband. The adjustment mechanisms7of these bimetallic strips5usually involve setscrews or dials, and due to the nature of the bimetallic strip5, it is difficult to precisely set the set temperature and the deadband.

Bimetallic strip controllers are convenient because they are small, mountable to any surface, durable and adaptable to numerous temperature ranges. They are also fairly reliable and inexpensive to produce for a specific application. Further, the bimetallic strip controller and, therefore, the entire control system can be mounted on a surface of the object or within the space to be controlled. All of the elements of the bimetallic strip controller can easily be made to withstand extremes of temperature so the set temperature can vary over a wide range. Further, no external connections or control are required.

Another conventional method to achieve temperature control is to use a solid-state controller.FIG. 2shows conventional solid-state controller approach. Object3, heater and cooler2and voltage source4are the same as that shown inFIG. 1. The temperature of object3is sensed by a temperature sensor12. This temperature sensor12might be a thermal couple, a dedicated semiconductor temperature sensor, a thermistor, a resistive temperature-sensing device (RTD) or the like. The temperature sensor12is connected by wiring13to a temperature controller15. The temperature controller15integrates several components. A controller10is used to compare the temperature measured by temperature sensor12to some reference14. The reference14is used to derive first and second preset temperatures around a set temperature. When the temperature sensed by temperature sensor12is below the first preset temperature, the controller10controls a power device11to allow current to pass from the voltage source4to the heater2. The power device may be a high-powered transistor thyristor, or TRIAC, or some manner of electromechanical relay to control the power. When the controller10measures a temperature above first preset temperature, the controller10controls power device11to switch preventing current flowing to heater2so that the object3cools. When the controller10measures a temperature below the second preset temperature, the controller10controls power device11to switch allowing current flowing to heater2so that the object3heats once more. As with the bimetallic strip controller, this process continues keeping the object3within a deadband around the set temperature.

The various components in the controller15are in general temperature sensitive but their performance is more susceptible to changes in temperature even to the point of destruction. Therefore, in these kinds of control systems only the temperature sensor12is generally placed on the object3or in the space, to be controlled (particularly where the object or space temperature are to be controlled to extremes of temperature). Other components are placed in controller15, which is often remotely placed in an environment that is less extreme than that of object3. This need to place temperature controller15in a less harsh environment than that of object3presents many issues with additional wiring, additional casing, and a need to find the less harsh environment.

A considerable advantage of bimetallic strip controllers such as that inFIG. 1, is that the components used to make the bimetallic strip controller can stand an extreme range of temperatures. The bimetallic strip controller can simply be mounted on the object, without the additional wiring and casing.

Bimetallic strips are still widely used because of the above issues with remotely placing the solid-state controller15. Bimetallic strips controllers, however, have problems of their own. If the currents to be controlled are large, and the heater or cooler load is inductive, large sparks are formed as the contacts are made and broken to switch on and off the heater or cooler. This rapidly destroys the contacts. There are many locations where the environment may contain explosive vapors or liquids, and these sparks may ignite fires or explosions. Further, to adjust the set point temperature and the deadband for a bimetallic strip is not trivial and often involves a number of set screws or dials that change the point at which the bimetallic strip will change from the first state to the second state. Adjusting the bimetallic strip device is, also difficult, as there is often not a good correlation between the set point of any individual screw or dial and the set point temperature or deadband. Further, because the accuracy of the set point temperature and the width of the deadband are imprecise, the width of the deadband often cannot be made relatively small. Conversely, even if the width of the deadband could be reduced, the width determines how often the contacts of the controller switch and therefore how fast the contacts wear.

Solid-state base controllers on the other hand can be very accurately controlled and the predetermined range relatively easily adjusted. Further, if a solid-state device controls the power, then there is no disadvantage for example with regard to contact wear, or the generation of sparks, that may cause ignition.

Solid-state controllers have one further advantage, which is that increasingly precise and sophisticated methods for controlling temperature can be implemented. For example, a heater or cooler may be varyingly controlled such that it is effectively maintained in a third state between an off and an on state. A power control device of a solid-state controller may operate in a pulse width modulation technique in which the heater or cooler is rapidly switched on and off, the ratio of on time to off time determining the heating or cooling. Because any heater or cooler can be operated somewhere between fully on and fully off, the solid-state controller can implement techniques such as a proportional integral differential (PID) algorithm to control the temperature. These algorithms lead to more accurate and stable temperature control because they have no deadband. Further, these algorithms stabilize temperature fast when the device is first switched on, and is moving towards a set temperature, or if external conditions around the object or space to be controlled change so that more or less heat is required.

SUMMARY

In view of the above, it would be advantageous to provide a solid-state temperature control device that has the advantages of limited size and being mounted fully and directly on the object or in the space to be controlled like that of a bimetallic strip controller, but also has the precision, safety and an adaptability of the solid-state circuiting.

In view of the above-discussed shortfalls, it may be advantageous to provide a solid-state control device with components for temperature measurement and control, and power control combined within one package to be mounted to an object, or in a space, whose temperature is to be controlled which avoids the negative impacts of the components for temperature measurement and control, and power control being at the temperature of the object. According to the exemplary embodiments a single package solid-state temperature controller may be adapted to be mounted to an object to be controlled or placed in a space to be controlled. The temperature controllable package and all of the components shall be capable of performing accurate temperature control even while being subjected to the same temperature as that of the object, and even in instances where the temperature is extreme.

The systems and methods according to this disclosure may provide a solid-state temperature controller integrated into a single package that can be mounted to a surface of an object to be controlled or the surface confining a space where temperature is to be controlled.

The systems and methods according to this disclosure may provide a solid-state controller integrated into a single package that can precisely control the temperature of an object or a space within the deadband of a set point temperature.

The systems and methods according to this disclosure may provide a solid-state temperature controller integrated into a single package that can provide PID control to the object or the space temperature.

The systems and methods according to this disclosure may provide an integrated solid-state controller in a single package that can be reprogrammed in situ, either by a wired or wireless connection to relatively easily change the set temperature and the deadband.

The systems and methods according to this disclosure may provide a solid-state temperature controller integrated into a single package that provides a safe alternative to bimetallic strip controllers in explosive or flammable environments. The systems and methods according to this disclosure may provide a part-for-part replacement by bimetallic strip controllers as an upgrade to the systems and methods already deployed in the field, or as a direct substitute for bimetallic strips in currently designed equipment.

The systems and methods according to this disclosure may provide a solid-state temperature controller integrated into a single package that provides temperature control of the temperature of an object or space to extreme temperatures in which the solid-state temperature controller, when subject to such extremes, continues to operate and control the temperature accurately.

The systems and methods according to this disclosure can and continue to operate, and control temperature, even when the object is at, or has been to, extreme temperatures far from the set temperature.

The systems and methods according to this disclosure provide a solid-state controller in which the temperature sensor is strongly thermally coupled to the object, or space, whose temperature is to be controlled but the remaining circuit elements are only weakly thermally coupled to both the temperature sensor, and the object, or space, whose temperature is to be controlled.

The systems and methods according to this disclosure provide a solid-state controller in which the various elements that comprise the solid-state controller are arranged to avoid mechanical stress on the elements due to differential thermal coefficients of expansion of the elements, and mechanical stress on the elements due to temperature gradients within the a solid-state controller.

These and other features and functions of the disclosed systems and methods are described in, or apparent from, the following detailed description of various exemplary embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS

Various exemplary embodiments of the disclosed systems and methods for providing an integrated solid-state controller that can be mounted on an object or in a space whose temperature is to be controlled are disclosed. These exemplary embodiments allow the integrated solid-state controller to operate at extreme temperature to which the object or space is controlled, yet still maintain the accuracy of the set temperature and, if the embodiment has a deadband, the accuracy of that deadband.

FIGS. 3 and 4show an exemplary embodiment of a system for temperature control. Temperature controller16is mounted directly on object3and controls the power from voltage source4to heater or cooler2in a similar manner to the system shown inFIGS. 1 and 2. Temperature controller16, unlike that of a bimetallic strip controller, is entirely solid-state.

As shown inFIG. 4various components are integrated inside the solid-state temperature controller16. A temperature sensor20is provided. The temperature sensor20may include any kind of solid-state temperature sensor including, for example, a thermal couple, thermistor, RTD, diode, dedicated semiconductor temperature measurement device, or the like. This disclosure is not limited to only these sensors, but any known or future-developed temperature measurement or sensor device could be used.

If an RTD is used then the RTD may be wired in a resistive bridge arrangement to reduce susceptibility of the measurement or sensor circuit to changes in temperature of the solid-state temperature controller.

A heat conductor26couples the temperature sensor thermally to the object3.

Temperature controller16may include a reference21. The reference provides either a standardized voltage or current that is compared to the output voltage of the temperature sensor20. The reference21may be any known or future developed reference component for voltage and current. However, the reference21must be stable to varying temperature. Also, any change in the value of the reference of the temperature must be known. This is because the solid-state temperature controller16will be at the same temperature as the object3to which it is attached. Therefore, any drift in output of the reference device due to changes in temperature of the object3and, therefore, the solid-state temperature controller16, must be compensated.

The solid-state temperature controller16may further include comparing unit22. The comparing unit22may be implemented in a number of ways, for example, as dedicated hardware, an FPGA, a PLA, an ASIC, a microcontroller or any other known or future method for implementing the a comparing unit22. The comparing unit22compares the temperature measured by temperature sensor20with a temperature set point or set points derived from a reference21. Based on this comparison, the comparing unit22may, in turn, control a power device23also contained in temperature controller16. Comparing unit22also must be specified to work under the extreme temperature range required by object3as the comparing unit22will also be at the same temperature as object3.

Power device23may be any device that can control a current delivered to a heater or cooler. Power device23may be, for example, a thyristor, TRIAC, power-FET, bipolar transistor or any other known or future developed like power control device. The control signals from comparing unit22switch power device23on and off allowing current to flow between leads24and25. Power device23should also be specified to work under any extreme temperature range required by object3. It must also switch the required voltages and currents at these extreme temperatures.

An exemplary temperature for the temperature controller16requires all components of the solid-state temperature controller16to operate without failure at extreme temperatures. For heater embodiments this includes temperatures above 70° C., and preferably above 90° C., and more preferably above 110° C. For cooler embodiments, this includes temperatures below 0° C., and preferably below −15° C. and more preferably below −30° C.

Temperature controller16may be programmed with a specific temperature set and deadband during manufacture and assembly. A range of temperature controller16may be manufactured with specific temperature sets or specific temperature ranges. Thus, for example, a particular temperature controller16may be manufactured that is specified for a set temperature of 100° C. with a deadband of 2° C. Temperature controller16may or may not be provided with a capacity to be reprogrammed to perform any other function. The set temperature may be anywhere in the preferable operating ranges with accuracy preferably at least 1° C. The deadband range, may preferably set as low as 5° C., and more preferably as low as 0.5° C.

To maintain temperature accuracy and maintain the integrity of the temperature controller16over the above temperature range a number of specific features are incorporated into the temperature controller16.FIGS. 5-7show an exemplary embodiment of the enclosure for the temperature controller16.

The enclosure102comprises a housing130that may be formed from a low thermal conductivity polymer capable of withstanding high temperatures. The polymer must withstand higher temperatures even than those indicated above because areas of the housing130that are in direct contact with the object3may experience transient temperatures outside those ranges. The low thermal conductivity of the polymer protects the rest of the temperature controller16from these transients. Suitable polymers may include, for example, mineral filled nylon.

The low thermal conductivity of the polymer additionally prevents the components inside the enclosure102from being subjected to thermal shock caused by rapid changes in temperature. Rapid changes in temperature within the enclosure may cause mechanical stress because temperature gradients can generate mechanical stress that can damage or break connections between components.

As shown inFIG. 5, the surface of the housing130that faces the object3may preferably be formed to include a concave facing surface123. When attached to the object3by mounting ears120, only the outermost edges of the housing130touch the object, further reducing the temperature conducted into the housing130.

FIG. 6shows a plan view from above the temperature controller16and side views of the temperature controller16. A thermally conducting element or heat conductor105is positioned to protrude from the concave facing surface123of the housing130. This protruding heat conductor105makes contact with the object3to be heated or cooled when the temperature controller16is mounted to the object3by mounting ears120. The heat conductor105is not fixed rigidly to the housing130but is attached by a bead of an elastic compound145, for example, room temperature vulcanization (RTV) silicone sealant. This non-rigid connection allows the protruding surface106of the heat conductor105to make contact with the object3over a large area, even if the surface of the object3and the facing surface106are not parallel or conformed before engagement. Further, the elasticity of the RTV silicone sealant means that the protruding surface106of the heat conductor105is held against the surface of the object3with a force corresponding to the deformation of the bead145. The heat conductor105is preferably made from a high thermal conductivity metal for example aluminum. More preferably, anodized aluminum may be used.

FIG. 7shows a cutaway through the temperature controller16along a line A′-A′. The heat conductor105is connected to a temperature sensor150by a non-rigid heat conductor115. This non-rigid heat conductor115may be formed from a thermally conducting grease, for example, heat sink compound or flexible silicone rubber based heat transfer pads. The heat sink compound or transfer pads allow the heat conductor105to move with respect to the temperature sensor150without breaking the thermal connection. If heat transfer pads are used the compression of these heat transfer pads will also add to the force that holds the heat conductor105against the object3when compressed.

The temperature sensor150is mounted to a circuit board160. This circuit board should also be capable of sustaining the large temperature range discussed above. The circuit board160may, for example, be made of Flame Retardant 4 (FR 4) material. The remaining circuit elements155used by the temperature controller16are, in this embodiment, mounted on the opposite side of the circuit board160and preferably away from the portion of the circuit board160on the opposite side of the temperature sensor150. The FR 4 material is also a poor thermal conductor and therefore isolates the temperature sensor150thermally from the rest of the temperature controller16components. Copper tracks electrically connecting the temperature sensor150to the rest of the circuit are designed to be long and narrow so as to reduce heat conduction via these tracks to the rest of the circuit. Further, the FR 4 material is made to be free of any other copper tracks or copper planes near to the temperature sensor150. This aids in isolating the temperature sensor150thermally from the rest of the temperature controller16, and means that the temperature of the temperature sensor150will closely track the temperature of the heat conductor105and, thus, the object3.

All parts for the circuit in this embodiment are specified, for operation at least within the automotive temperature range of −40° C. to +125° C. The remaining circuit elements155may include a microcontroller156and voltage regulator157for providing a low voltage to the microcontroller150. The voltage regulator157also providing low-power standby functions by shutting down power to various parts of the circuitry when required.

The voltage regulator157may also provide an internally compensated voltage reference with the stability of (+0/−0.5%) worst case over the specified operating range.

In this embodiment, the supply voltage to the circuit board160is preferably between 6V DC to 24V DC. This power may be supplied by insulated cables100and110. As well as supplying the voltage regulator157this voltage may supply high voltage switching components for the power device23that is also mounted on circuit board160. This disclosure is not limited to voltages between 6V DC to 24V DC. High voltage versions may also be implemented with the other features disclosed. Further, versions of the temperature controller16may also be implemented that are supplied with AC voltages of different frequencies and voltages.

In this embodiment, the comparing unit22is implemented with the microcontroller156that includes an internal A/D converter, with the internally compensated voltage reference of the voltage regulator157providing a reference for the microcontroller's internal A/D converter.

The temperature sensor150is preferably an RTD. The RTD is mounted in a resistor bridge the resistors158for the bridge mounted on the circuit board160at some distance from the RTD with the other circuit elements155. The resistor bridge configuration is driven in this embodiment by the internally compensated voltage reference in the voltage regulator157. Because both the resistor bridge reference voltage and the reference voltage for the A/D converter in the microcontroller are identical, drift of this voltage reference does not affect any temperature measurement.

Despite the above features to prevent thermal gradients within the temperature controller from affecting the integrity of the circuit board160and the components attached to the circuit board160, the circuit board160itself will still expand and contract depending upon the temperature of the object3. Rigidly mounting the circuit board160within the housing, for example, would cause the circuit board160to warp as the temperature changes. This may damage the circuit board160or destroy connections between the circuit board160and the components mounted to it. For this reason, the circuit board160is attached to the housing130by self tapping screw165and O-rings125. These self tapping screws165hold the circuit board160to the housing130by holes in the circuit board160. The holes are large enough that there is play between the self tapping screws165and the circuit board160. The O-rings125are made of an elastic material and are placed between the circuit board160and the housing130. The self tapping screws165go through holes in the O-rings125and are tightened so as not to fully compress the O-rings125. This allows the circuit board160to expand and contract without warping, but the compressed O-rings125hold the circuit board160in place so that good contact is maintained between the temperature sensor150and the heat conductor115.

To prevent incursion of, for example, dust, mist, spray and snow the upper portion of the circuit board160and the components155mounted there, the upper portion is encapsulated in a potting compound140. The potting compound140is selected so that relative differences in thermal expansion between the potting compound140and the circuit board160and components do not cause stress that damages the components155or any connections between the components. For this reason, potting compounds with relative high pliability, low coefficient of expansion, low residual stress due to curing and wide temperature ranges are used. An example of such a potting compound140is the polymer Tough-Seal 21™ manufactured by Key Polymer Corporation. The potting compound140thus protects the components attached to the circuit board160and acts as a cable clamp for wires24,25,100and110that emerge from the potting compound140.

The temperature controller16may include additional features to make programming and set up of the temperature controller16more convenient. As shown inFIG. 8, a port30may be added to the temperature controller16. By connecting a separate programmer to port30, the comparing unit22may be reprogrammed, for example, with a different set point temperature and deadband. Using such a compatible programmer, a single temperature controller16may be manufactured and then either programmed appropriately before shipping to a customer or shipped to a customer and then programmed by the customer. The temperature controller16could then also be reprogrammed at any time, or could also be a one time programmable device. The one time programmable device may be appropriate where it is determined that it is essential that the device cannot be reprogrammed once installed in its final location.

FIG. 9shows an alternate embodiment. In this embodiment, an antenna31and a receiver and decoder32may be incorporated into the solid-state temperature controller16. Using a wireless transmitter connected to a wireless programmer, the programmer could then program the comparing unit22via the wireless link to antenna31, and receiver and decoder32. This device may allow the solid-state temperature controller16to be reprogrammed with a new set point temperature and deadband using the wireless programmer. This may allow the solid-state temperature controller16to be reprogrammed at any time in its life. Moreover, solid-state temperature controllers16installed in areas that are inaccessible due to confined spaces or even hostile environments, can be reprogrammed at any time from a safe distance or safe environment.

FIG. 10illustrates various features that may be incorporated into comparing unit. A set temperature storage unit40may store the present or programmable set temperature. A deadband storage unit41may store a range of temperature of which the object3is allowed to vary based on the output from the reference21and the value stored in the set temperature set storage unit40and the deadband storage unit41

A range generation unit42may generate an upper temperature reference45and lower temperature reference46. Comparators43and44may compare the temperature from the temperature sensor20to the upper temperature reference45and the lower temperature reference46. The outputs from comparators43and44may be fed into a logic unit47. If the temperature from temperature sensor20exceeds upper temperature reference45, the logic unit47may send a signal on output wire48to switch off power control device23. If the temperature from temperature sensor20is below lower temperature reference46, the logic unit47may send a signal on output wire48to switch on power control device23. This solid-state circuit mimics the control function formed by a bimetallic strip.

Because a solid-state device is used for control, the control function is not limited to circuits above that mimic the control performed by a bimetallic strip controller, and more sophisticated control mechanisms can also be adapted.

FIG. 11illustrates a system for providing PID control for temperature control in the solid-state temperature controller16. A temperature set point storage unit50may be used to store a set point temperature. Analog to digital converter52may convert the temperature measured by temperature sensor20into a digital value based upon a reference voltage provided by reference24.

A comparator unit51may compare the output from analog to digital converter52with the stored set point value and may generate an error signal53indicating the error between the set temperature value and the current temperature. Error signal53may be fed into a proportional integral differential controller54(PID). The HD may generate a signal corresponding to the heating or cooling required to reduce the error generated by comparator51. The output is based on the value stored in proportional storage unit55, integral storage unit56and differential storage unit57. HD controllers are well known in the art and will not be described in more detail.

The output from the PID controller may be fed to a converter58. Converter58may convert the output from PID controller54into a digital signal whose time average, for a predetermined time interval, corresponds to the output of the PID controller54. Converter58may be, for example, a pulse width modulation device, frequency modulation device, phase modulation device or any other known converter or future converter that performs this function. A converted signal may be fed to the power control device23via output59. The advantage of this controller is that the time average power supplied by the heater can be somewhere between the heater or cooler being fully on and fully off. Thus, if the object3is at slightly too high a temperature, the temperature controller16can slightly reduce the time average power supplied to a heater until the temperature is correct. Thus, there is no deadband range when using this kind of controller. Further, if for some reason conditions around the object3change so that the heat lost changes, the temperature controller16can adapt and supply slightly more or less power to maintain constant temperature.

The proportional, integral and differential signals may be set at manufacture in the same manner as the set temperature and the deadband described above. The proportional, integral and differential values are critical to maintaining the stability of the control system formed by temperature control16and the heat capacity and heating power of the object3and heater or cooler12, respectively. A system with inappropriate proportional, integral and differential values may not maintain a stable temperature. It will either oscillate between extremes of temperature, or never reach the set temperature. Therefore, from application to application, the proportional, integral and differential values will be different, and an installer may have to program these values based on experimental or modeled data for the object3and the heater or cooler2. Programming techniques using a port30or the antenna31and radio receiver and decoder32as shown inFIGS. 5 and 6can be used to program the proportional, integral and differential values as needed.

FIG. 12shows an alternate embodiment for temperature control in the solid-state temperature controller that removes this need to program the proportional, integral and differential values. Auto-tuning unit60may monitor the performance of the controller formed by temperature controller16, heater or cooler2and object3. The auto-tuning unit60may modify the proportional, integral and differential values to prevent the system from oscillating but also to allow the system to reach an equilibrium temperature as fast as possible. In this manner, the PID controller may be adapted to a system in which it is placed, without the need to be specifically programmed.