Solid state lighting, driver circuits, and related software
LED lighting fixtures, or luminaires, related components, driver circuit, methods, and software/firmware are described that can provide for among other things, ambient environment sensing, thermal self-monitoring, sensor-based power management, communications, and/or programmability. Driver and lighting circuits configured for electrical loads such as series arrangements of light emitting diodes are also described. Embodiments of PFC stages and driver stages can be combined for use as a power supply, and may be configured on a common circuit board. Power factor correction and driver circuits can be combined with one or more lighting elements as a lighting apparatus. Methods of hysteretic power factor correction start-up are also described.
1. A solid state lighting driver circuit comprising:
an EMI filter configured and arranged to receive an AC input from an AC power supply;
a rectifier connecting the EMI filter, the rectifier being configured and arranged to receive AC power from the EMI filter and produce a rectified current;
a power factor correction (PFC) stage including a boost circuit connected to the rectifier, the boost circuit being configured and arranged to receive the rectified current and to produce a power factor corrected output with a higher voltage than the AC input of the AC power supply;
a Buck regulator configured and arranged to receive power from the PFC stage and regulate power for supply to a plurality of LEDs; and
a controller configured and arranged to control the Buck regulator and PFC stage for hysteretic PFC start-up, wherein the controller is configured and arranged to (i) with the output current of the PFC stage at zero, and with the Buck regulator in an off condition, cause the PFC stage to turn on and begin to charge a boost capacitor, (ii) when a desired high fixed voltage across the boost capacitor is reached, turn the Buck regulator on at a low current value and turn off the PFC stage allowing the boost capacitor to discharge to a lower fixed voltage as it supplies current to the plurality of LEDs, (iii) adjust a ramp-up voltage time, between the lower fixed voltage and the high fixed voltage, to equal a ramp-down voltage time between the high fixed voltage and the lower fixed voltage, and (iv) turn the PFC stage back on.
2. The circuit of claim 1 , wherein the EMI filter is configured and arranged to receive a 120 V AC input and the boost circuit is configured and arranged to produce an output of about 500 V DC.
3. The circuit of claim 1 , wherein the controller is configured and arranged to provide PWM control of the Buck regulator.
4. The circuit of claim 1 , further comprising a communications circuit configured and arranged to communicate with a solid state lighting (SSL) circuit.
5. The circuit of claim 4 , wherein the communications circuit operates with a protocol selected from the group consisting of DALI, 0-10v Analog, 4-20 maA analog, LIN, CAN, RS-232, RS-422, RS-485, Ethernet, Flexray, Zigbee, DASH7.
6. A lighting power supply comprising:
(i) a PFC stage including:
an EMI filter configured and arranged to receive an AC input from an AC power supply;
a rectifier connecting the EMI filter portion, the rectifier being configured and arranged to receive AC power from the EMI filter and produce a rectified current; and
a boost portion connected to the rectifier, the boost portion being configured and arranged to receive the rectified current and to produce a power factor corrected output with a higher voltage than the AC input of the AC power supply; and
(ii) a driver stage, configured and arranged to receive output from the PFC stage and supply as an output power to an electrical load, the driver stage including a Buck regulator; and
(iii) a controller configured and arranged to control the Buck regulator and PFC stage for hysteretic PFC start-up, wherein the controller is configured and arranged to (i) with the output current of the PFC stage at zero, and with the Buck regulator in an off condition, cause the PFC stage to turn on and begin to charge a boost capacitor, (ii) when a desired high fixed voltage across the boost capacitor is reached, turn the Buck regulator on at a low current value and turn off the PFC stage allowing the boost capacitor to discharge to a lower fixed voltage as it supplies current to the electrical load, (iii) adjust a ramp-up voltage time, between the lower fixed voltage and the high fixed voltage, to equal a ramp-down voltage time between the high fixed and the lower fixed voltage and (iv) turn the PFC stage back on.
7. A lighting apparatus comprising:
(i) a PFC stage including:
an EMI filter configured and arranged to receive an AC input from an AC power supply;
a rectifier connecting the EMI filter portion, the rectifier being configured and arranged to receive AC power from the EMI filter and produce a rectified current; and
a boost portion connected to the rectifier, the boost portion being configured and arranged to receive the rectified current and to produce a power factor corrected output with a higher voltage than the AC input of the AC power supply; and
(ii) a power regulation circuit including a Buck regulator, configured and arranged to receive output from the PFC stage and supply as an output power to an electrical load;
(iii) a controller configured and arranged to control the Buck regulator and PFC stage for hysteretic PFC start-up, wherein the controller is configured and arranged to (i) with the output current of the PFC stage at zero, and with the Buck regulator in an off condition, cause the PFC stage to turn on and begin to charge a boost capacitor, (ii) when a desired high fixed voltage across the boost capacitor is reached, turn the Buck regulator on at a low current value and turn off the PFC stage allowing the boost capacitor to discharge to a lower fixed voltage as it supplies current to the one or more lighting elements, (iii) adjust a ramp-up voltage time, between the lower fixed voltage and the high fixed voltage, to equal a ramp-down voltage time between the high fixed and the lower fixed voltage, and (iv) turn the PFC stage back on; and
(iv) one or more lighting elements configured and arranged to receive power from the power regulation circuit.
8. The lighting apparatus of claim 7 , wherein the one or more lighting elements comprise one or more LEDs.
9. The lighting apparatus of claim 7 , further comprising an optical sensor to detect ambient light.
10. The lighting apparatus of claim 7 , further comprising a motion detector to detect motion.
11. A lighting apparatus comprising:
(i) a PFC stage including:
an EMI filter configured and arranged to receive an AC input from an AC power supply;
a rectifier connecting the EMI filter portion, the rectifier being configured and arranged to receive AC power from the EMI filter and produce a rectified current; and
a boost portion connected to the rectifier, the boost portion being configured and arranged to receive the rectified current and to produce a power factor corrected output with a higher voltage than the AC input of the AC power supply;
(ii) a power regulation circuit including a Buck regulator, configured and arranged to receive output from the PFC stage and supply as an output power to an electrical load;
(iii) a controller configured and arranged to control the Buck regulator and PFC stage for hysteretic PFC start-up;
(iv) one or more lighting elements configured and arranged to receive power from the power regulation circuit;
(v) a motion detector to detect motion, and
(vi) a luminaire housing with an aperture and a motion sensor module plate connected to the housing, wherein the motion sensor is disposed on a motion sensor circuit board connected to the motion sensor module plate, and wherein the motion sensor module plate comprises a seal for the motion sensor module.
12. A method of providing hysteretic power factor correction (PFC) start up for a LED luminaire, the method comprising:
(i) with the output current of the PFC stage at zero, and with the Buck regulator in an off condition, causing the PFC stage to turn on and begin to charge a boost capacitor;
(ii) when a desired high fixed voltage across the boost capacitor is reached, turning off the Buck regulator at a low current value and turning off the PFC stage allowing the boost capacitor to discharge to a lower fixed voltage as it supplies current to the LED luminaire;
(iii) adjusting a ramp-up voltage time, between the lower fixed voltage and the high fixed voltage, to equal a ramp-down voltage time between the high fixed and the lower fixed voltage; and
(iv) turning the PFC stage back on.