Light-emitting diodes as shunt regulator to power low-voltage circuits
Light-emitting diode (LED) fixture circuits and devices with LEDs as shunt voltage regulators to power low-voltage circuits are disclosed. LED fixture circuits and devices are disclosed where a direct current (DC) input voltage supplied to an LED array of a plurality of LEDs is regulated using a shunt LED comprising one or more LEDs. The shunt LED is configured to provide a regulated voltage lower than the DC input voltage while generating a light that contributes to the overall luminescence of a given circuit or device.
1. A light-emitting diode (LED) fixture circuit, comprising:
a first LED array comprising a plurality of LEDs connected in series, parallel, or a combination thereof between a first input node and a first output node;
a first shunt LED comprising one or more LEDs connected in series, parallel, or a combination thereof between a second input node and a second output node; and
a first shunt terminal that outputs a first regulated voltage generated at the second input node;
wherein the first input node and the second output node are configured to have a potential difference equal to a direct current (DC) input voltage, and the first output node couples to the second input node; and
wherein the first regulated voltage equals a forward voltage drop across the first shunt LED and the first regulated voltage is lower than the DC input voltage.
2. The LED fixture circuit according to claim 1 wherein the first input node is supplied with a constant DC input current in the range of 0 mA to 2000 mA.
3. The LED fixture circuit according to claim 2 wherein the DC input voltage is in the range of 12V to 200V.
4. The LED fixture circuit according to claim 2 wherein the first shunt LED comprises one or more series-connected LEDs between the second input node and the second output node with the forward voltage drop in the range of 2V to 12V.
5. The LED fixture circuit according to claim 2 wherein the first shunt LED further comprises two or more substantially similar LEDs connected in parallel between the second input node and the second output node with the forward voltage drop in the range of 2V to 12V.
6. The LED fixture circuit according to claim 1 wherein each LED forming part of the first LED array and the first shunt LED is configured to generate a white, a red, a green, a blue, a yellow, or an amber light, or light that is a mixture thereof.
7. The LED fixture circuit according to claim 1 further comprising:
a second shunt LED comprising one or more LEDs connected in series, parallel, or a combination thereof between a third input node and a third output node; and
a second shunt terminal that outputs a second regulated voltage generated at the third input node;
wherein the first output node couples to the second input node via the second shunt LED such that the third input node connects to the first output node and the third output node connects to the second input node; and
wherein the second regulated voltage equals a forward voltage drop across the second shunt LED and the first shunt LED and the second regulated voltage is higher than the first regulated voltage and lower than the DC input voltage.
8. The LED fixture circuit according to claim 7 further comprising:
a second LED array comprising a plurality of LEDs connected in series, parallel, or a combination thereof between a fourth input node and a fourth output node;
a third shunt LED comprising one or more LEDs connected in series, parallel, or a combination thereof between a fifth input node and a fifth output node; and
a third shunt terminal that outputs a third regulated voltage generated at the fifth input node;
wherein the fourth input node connects to the first input node and the fifth output node connects to the second output node and are configured to have a potential difference equal to the (DC) input voltage; and
wherein the fourth output node couples to the fifth input node, and the third DC regulated voltage equals a forward voltage drop across the third shunt LED and the third regulated voltage is lower than the first DC input voltage.
9. The LED fixture circuit according to claim 8 wherein the third regulated voltage is in the range of 2V to 12V.
10. The LED fixture circuit according to claim 8 wherein each LED forming part of the first LED array, the second LED array, the first shunt LED, the second shunt LED, and the third shunt LED is configured to generate a white, a red, a green, a blue, a yellow, or an amber light, or light that is a mixture thereof.
11. An LED fixture device, comprising:
a positive supply terminal and a negative supply terminal configured to have a potential difference equal to a direct current (DC) input voltage;
a first low-voltage electronic device having a first positive supply pin and a first negative supply pin;
a first LED array comprising a plurality of LEDs connected in series, parallel, or a combination thereof between a first input node and a first output node;
a first shunt LED comprising one or more LEDs connected in series, parallel, or a combination thereof between a second input node and a second output node; and
a first shunt terminal that supplies a first regulated voltage generated at the second input node and is coupled to the positive supply pin to operate the first low-voltage electronic device;
wherein the first input node connects to the positive supply terminal, the second output node and the first negative supply pin connect to the negative supply terminal, the first output node couples to the second input node; and
wherein the first regulated voltage equals a forward voltage drop across the first shunt LED and the first regulated voltage is lower than the DC input voltage.
12. The LED fixture device according to claim 11 wherein the first low-voltage electronic device requires a voltage in the range of 2V to 12V for operation.
13. The LED fixture device according to claim 11 wherein the first low-voltage electronic device requires a nominal voltage equal to one or more of 2.0V, 3.0V, 3.3V, 5.0V, 9.0V, or 12.0V for operation.
14. The LED fixture device according to claim 11 further comprising a low-voltage regulator having an input pin and an output pin, wherein the first shunt terminal and the positive supply pin couple via the low-voltage regulator such that the first regulated voltage is connected to the input pin of the low-voltage regulator and the positive supply pin of the first low-voltage electronic device connects to the output pin of the low-voltage regulator configured to further regulate the first regulated voltage.
15. The LED fixture device according to claim 14 wherein the first low-voltage electronic device requires a nominal voltage equal to one or more of 2.0V, 3.0V, 3.3V, 5.0V, 9.0V, or 12.0V for operation.
16. The LED fixture device according to claim 11 wherein a power supply terminal connects to an external LED driver configured to receive an alternating current (AC) input voltage from a power supply source and supply a constant DC input current in the range of 0 mA to 2000 mA through the positive supply terminal.
17. The LED fixture device according to claim 16 wherein the DC input voltage is in the range of 12V to 200V.
18. The LED fixture device according to claim 11 wherein the first low-voltage electronic device is one of a processing unit, a control unit, a sensor, a data storage unit, a wireless transmitter/receiver, or a low-voltage integrated circuit.
19. The LED fixture device according to claim 11 wherein each LED forming part of the first LED array and the first shunt LED is configured to generate a white, a red, a green, a blue, a yellow, or an amber light, or light that is a mixture thereof.