Patent ID: 12238835

DETAILED DESCRIPTION OF THE INVENTION

FIG.1is a block diagram of a linear light-emitting diode (LED) lamp according to the present disclosure. A linear LED lamp110is used to replace a fluorescent or an LED lamp normally operated with the AC mains in a normal mode. InFIG.1, the linear LED lamp110comprises a normal driver311, a load control relay circuit660, an emergency-operated portion810, and an LED assembly200comprising one or more LED arrays214with a forward voltage across thereof. The emergency-operated portion810comprises a rechargeable battery500, a control and test circuit700, and a step-up regulator circuit760configured to transfer a power from the rechargeable battery500to provide an emergency power (i.e., a voltage and a current) to drive the one or more LED arrays214when the line voltage from the AC mains is unavailable. The normal driver311comprises at least two electrical conductors, “L” and “N”, at least one full-wave rectifier301, and a step-down regulator circuit303. The step-down regulator circuit303comprises a second inductor304and a power switching control circuit305. The at least one full-wave rectifier301is configured to convert the line voltage from the AC mains into a primary DC voltage. In other words, the at least two electrical conductors, “L” and “N”, are coupled to an un-switched power. However, the normal driver311can be turned off when the linear LED lamp110is not in use or during nighttime by controlling an enabling/disabling port315in the power switching control circuit305. The un-switched power ensures that the rechargeable battery500always receives a power from the line voltage to charge.

The power switching control circuit305is coupled to the at least one full-wave rectifier301and configured to allow the step-down regulator circuit303to generate a second LED driving current to power up the one or more LED arrays214at a full power when the line voltage is available. The power switching control circuit305further comprises a second control device306comprising the enabling/disabling port315configured to receive a second control signal from the control and test circuit700and to either enable or disable the step-down regulator circuit303. The step-down regulator circuit303, a normally-operated current source, may further comprise a rectifier307and a capacitor308and is configured to provide the second LED driving current to the one or more LED arrays214to operate thereon. The LED assembly200further comprises a first terminal LED+ (i.e., a positive potential terminal of the one or more LED arrays214) and a second terminal LED−. The first terminal LED+ is configured to receive the second LED driving current in a forward direction whereas the second terminal LED− is configured to receive the second LED driving current returned from the one or more LED arrays214in a backward direction. The LED assembly200may further comprise an electric current distribution switch210coupled to an input of the one or more LED arrays214. The one or more LED arrays214may comprise two types of LEDs with two different correlated color temperatures (CCTs), for example, a first type of LEDs215at 3500 Kelvin (K) and a second type of LEDs216at 5000 K. The electric current distribution switch210is configured to distribute the second LED driving current to flow into the two types of LEDs. When the second LED driving current being equally divided flows into the first type of LEDs215and the second type of LEDs216, a third CCT at 4000 K appears as a result of color-mixing of the two different CCTs. The electric current distribution switch210is thereby configured to distribute the second LED driving current to flow into the first type of LEDs215and the second type of LEDs216resulting in an apparent light emission at a third CCT as a result of color-mixing of light emissions from both the first type of LEDs215and the second type of LEDs216.

As shown inFIG.1, the second LED driving current flowing in both directions is via the load control relay circuit660, quite different from a conventional non-load control approach. The load control relay circuit660comprises a voltage sensing coil661and is configured to control the second LED driving current to flow into and out of the one or more LED arrays214. The load control relay circuit660further comprises a first pair of electrical terminals662, a second pair of electrical terminals663, and a third pair of electrical terminals664. The first pair of electrical terminals662are configured to couple to the step-down regulator circuit303and to relay the second LED driving current to flow into the one or more LED arrays214. The second pair of electrical terminals663are configured to relay the second LED driving current returned from the one or more LED arrays214to flow into a ground reference256of the step-down regulator circuit303. The third pair of electrical terminals664are configured to couple to the terminal voltage of the rechargeable battery500to operate the voltage sensing coil661. When the line voltage is available, the voltage sensing coil661is operated in a position shown inFIG.1with the first pair of electrical terminals662and the second pair of electrical terminals663respectively electrically conducted. The second LED driving current can therefore flow into and out of the one or more LED arrays214, continuing a power transfer to the one or more LED arrays214.

The emergency-operated portion810further comprises a power source704configured to couple to the at least one full-wave rectifier301and to provide a DC power to the control and test circuit700and a charging voltage to the rechargeable battery500, pre-powering the emergency-operated portion810. The rechargeable battery500comprises a high-potential electrode501and a low-potential electrode502with a terminal voltage across thereon. The power source704provides the DC power to charge the rechargeable battery500to reach a nominal value of the terminal voltage. Note that the terminal voltage of the rechargeable battery500may be slightly less than the nominal value because the rechargeable battery500ages or an ambient temperature is below an optimum operating temperature. When the rechargeable battery500badly ages or goes wrong, the terminal voltage may be far from the nominal value. That is why the rechargeable battery test is needed to ensure that the rechargeable battery500is working all the time, especially in an event of power outage.

The step-up regulator circuit760comprises a first inductor761, a first control device762, at least three diode rectifiers763,764,765, and three or more capacitors766,767,768. The step-up regulator circuit760is configured to energetically charge the three or more capacitors766,767,768in multiple stages to convert the terminal voltage of the rechargeable battery500into controllable energy pulses, followed by the three or more capacitors766,767,768, building a regulated output voltage greater than the forward voltage with a first LED driving current. The regulated output voltage derived from the diode rectifier765and the capacitor768is coupled to the first terminal LED+ in parallel with an output from the step-down regulator circuit303and both ready to operate the one or more LED arrays214, depending on which one is an LED driving current source. Because the regulated output voltage is applied in front of the electric current distribution switch210, a proportion of the first LED driving current to flow into the first type of LEDs215and the second type of LEDs216is the same as the one of the second LED driving current, thereby keeping the third CCT in response to the second LED driving current unchanged.

The control and test circuit700may further comprise a power failure detection circuit703configured to detect whether the line voltage is available or not. According to this detection, the control and test circuit700is configured to enable and to disable the step-up regulator circuit760. To enable the step-up regulator circuit760, the control and test circuit700must send a logic high level signal to the first control device762to initiate an electronic switching in the step-up regulator circuit760. The control and test circuit700further comprises a first control port701configured to output the logic high level signal to the first control device762and to initiate the electronic switching in the step-up regulator circuit760when either the line voltage is not available or the rechargeable battery test is initiated. The control and test circuit700further comprises a second voltage detection circuit732configured to provide an indication of whether the step-up regulator circuit760is activated with an emergency lighting turned on or not.

InFIG.1, the control and test circuit700further comprises a first control circuit730comprising an electronic switch731configured to be turned on to control the terminal voltage to apply to the voltage sensing coil661to operate thereof via a first link751. The electronic switch731may comprise at least one metal-oxide-semiconductor field-effect transistor (MOSFET) or bipolar junction transistor (BJT). When the electronic switch731is turned off, the voltage sensing coil661is disabled with the second LED driving current interrupted. In that case, the first control circuit730may be configured to forbid the second LED driving current to flow into the one or more LED arrays214during the rechargeable battery test. The control and test circuit700further comprises a second control port702configured to output a signal via a second link752to turn off the power switching control circuit305when the step-up regulator circuit760is turned on.

InFIG.1, the control and test circuit700further comprises a test portion742and a self-diagnostic circuit740comprising at least one timer741. The at least one timer741comprises a first time delay and a second time delay. Upon an initiation of the at least one timer741, the first time delay begins with an input voltage applied on the self-diagnostic circuit740. At an end of the first time delay, the output of the self-diagnostic circuit740is activated to reach the logic high level and remains activated so as to send a logic high level signal to enable the step-up regulator circuit760for the second time delay. At an end of the second time delay, the output of the self-diagnostic circuit740is inactivated to drop to the logic low level. During the second time delay the self-diagnostic circuit740is allowed to integrate with the test portion742and to perform a rechargeable battery test. When the rechargeable battery test is initiated, the control and test circuit700is configured to send a logic low level to the step-down regulator circuit303and to disable thereof. At the same time, the voltage sensing coil661is disabled to forbid the second LED driving current to flow into and out of the one or more LED arrays214. The emergency-operated portion810further comprises a voltage drop circuit710configured to be interfaced between the charging voltage provided by the power source704and the terminal voltage. The voltage drop circuit710may comprise a diode and a resistor. The emergency-operated portion810further comprises a first voltage detection circuit711configured to compare the terminal voltage with the charging voltage and to detect whether the rechargeable battery is in a charged condition at all times when the line voltage is available. The first voltage detection circuit may comprise an operational amplifier with two input ports each respectively receives the terminal voltage and the charging voltage whereas an output of the operational amplifier dictates either a logic low level or a logic high level, respectively depending on whether the charging voltage is greater than the terminal voltage or not. The control and test circuit700may further comprise a first status indicator734configured to show a charging status. The control and test circuit700may further comprise a second status indicator735configured to show that the step-up regulator circuit760is enabled with a status of an emergency light “on”. The emergency-operated portion810may further comprise a peripheral circuit713configured to sample a fraction of the terminal voltage and to deliver to the test portion742to examine during the second time delay when the rechargeable battery test is initiated. The control and test circuit700may further comprise a test switch736configured to manually initiate the rechargeable battery test. The test switch736is further configured to manually cause or trigger the self-diagnostic circuit740to terminate the rechargeable battery test that is in progress. When the rechargeable battery test is manually initiated, the self-diagnostic circuit740is configured to ignore the first time delay and to activate the output of the self-diagnostic circuit740to reach the logic high level and remains activated so as to enable the step-up regulator circuit760for the second time delay. At an end of the second time delay, the output of the self-diagnostic circuit740is inactivated to drop to the logic low level. During the second time delay, the self-diagnostic circuit740is allowed to integrate with the test portion742and to perform a rechargeable battery test, as mentioned above. The control and test circuit700further comprises at least one status indicator737configured to show a result of the rechargeable battery test.

InFIG.1, the control and test circuit700further comprises an electrical conductor “L′” configured to couple to “L” via an external power switch360. The power failure detection circuit703is further configured to distinguish between a power failure and an external power switch360being turned off. When the line voltage is not detected, the control and test circuit700sends signals to disable step-down regulator circuit303and to enable the step-up regulator circuit760to generate the first LED driving current. The control and test circuit700may comprise a microcontroller, a microchip, or a programmable logic controller. In this disclosure, the emergency-operated portion810is integrated into the linear LED lamp110with the self-diagnostic circuit740to auto-test the terminal voltage of the rechargeable battery500in charging and discharging conditions with test results displayed in the at least one status indicator737, supporting dual mode operations of the linear LED lamp110to work not only in a normal mode but also in an emergency mode.

FIG.2is a timing diagram of a self-diagnostic circuit according to the present disclosure. As mentioned in depictingFIG.1, the self-diagnostic circuit740comprises the at least one timer741and the test portion742. The at least one timer741respectively comprises a first time delay834with a duration of T1 and a second time delay835with a duration of T2 immediately followed the first time delay834. Upon an initiation of the at least one timer741, the first time delay834begins with an input voltage738applied. At the end of the first time delay834, an output739of the self-diagnostic circuit740is activated to reach the logic high level (i.e., “1” state) and remains activated so as to enable the step-up regulator circuit760and the test portion742for the second time delay835. At the end of the second time delay835, the output739of the self-diagnostic circuit740is inactivated to drop to the logic low level (i.e., “0” state). The first time delay834and the second time delay835form a primary sequence with a duration of T1+T2. The primary sequence with the duration of T1+T2 repeats eleven times836until the terminal voltage (FIG.1) is removed from the self-diagnostic circuit740. InFIG.2, the input738shown comprises two states “0” and “1”, in which “0” means no voltage appeared at the input738of the self-diagnostic circuit740whereas “1” means the terminal voltage is applied. Similarly, the output739shown comprises two states “0” and “1”, in which “0” means no voltage appeared or being inactivated at the output739of the self-diagnostic circuit740whereas “1” means that the output739of the self-diagnostic circuit740provides a high-level output voltage or is activated. The duration T2 over the second time delay835is configured (e.g., being sufficiently long) to allow the self-diagnostic circuit740to perform the rechargeable battery test. It should be the same as the self-diagnostic circuit740sends a high-level signal to enable the step-up regulator circuit760(inFIG.1) during the second time delay835. The first time delay834comprises a nominal duration of 30 days. The second time delay835comprises a nominal duration of 30 seconds. Specifically, the primary sequence with the duration of T1+T2 repeats eleven times, as mentioned. At the twelfth time, the respective second time delay837comprises a nominal duration of 90 minutes. A combination of the primary sequence834,835repeating eleven times836and the twelfth time834,837forms a secondary sequence. The secondary sequence repeats until the DC power is removed from the self-diagnostic circuit740.

FIGS.3˜6are waveforms of controllable energy pulses and the regulated output voltage according to the present disclosure. Upon receiving the logic high level signal from the first control port701(FIG.1) when either the line voltage is not available or the rechargeable battery test is initiated, the step-up regulator circuit760initiates the electronic switching.FIG.3is an electronic switching waveform according to the present disclosure. InFIG.3, an electronic switching waveform951comprises switching pulses931with respect to a ground reference932, which is 0 volt. As depicted inFIG.1, at least three diode rectifiers763,764,765and three or more capacitors766,767,768are used to energetically charge the three or more capacitors766,767,768in a cascaded manner (in multiple stages). The switching frequency of the electronic switching waveform951is high enough to ensure that the each of three or more capacitors766,767,768can be of a small size.FIG.4is a waveform generated by rectifying and filtering according to the present disclosure. InFIG.4, a first DC voltage952with respect to the “0” volt is formed by rectifying the electronic switching waveform951using a first diode rectifier763, followed by filtering out a ripple waveform (not shown) using a first capacitor766.FIG.5is a waveform raised by a DC voltage according to the present disclosure. InFIG.5, a waveform953with respect to the “0” volt picks up the electronic switching waveform951but is raised by the first DC voltage952via a second diode rectifier764and a second capacitor767.FIG.6is a waveform showing a regulated output voltage according to the present disclosure. InFIG.6, the regulated output voltage954with respect to the “0” volt is formed by rectifying the waveform953using a third diode rectifier765, followed by a third capacitor768. The regulated output voltage954is, therefore, raised this way to be greater than the forward voltage across the one or more LED arrays214to operate thereon with the first LED driving current.

Whereas preferred embodiments of the present disclosure have been shown and described, it will be realized that alterations, modifications, and improvements may be made thereto without departing from the scope of the following claims. Another kind of schemes with an emergency-operated portion with a low emergency power circuit and multiple timers and multiple time delays adopted to operate a linear LED lamp using various kinds of combinations to accomplish the same or different objectives could be easily adapted for use from the present disclosure. Accordingly, the foregoing descriptions and attached drawings are by way of example only and are not intended to be limiting.