Power factor correction and driver circuits

Abstract

Power factor correction and driver circuits and stages are described. More particularly, power factor correction circuits are described that utilize an auxiliary inductor winding for power regulation. Driver circuits configured for electrical loads such as series arrangements of light emitting diodes are also described. An exemplary embodiment of a driver circuit can implement a comparator and/or a voltage regulator to allow for improved output current uniformity for high-voltage applications and loads, such as series configurations of LEDs. 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.

1 . A lighting apparatus and power factor correction (PFC) circuit comprising:
 a EMI filter configured and arranged to receive a 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 boost circuit connected to the rectifier and including a PFC controller and a PFC coil with an auxiliary winding, 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; and   a voltage regulator connected to the auxiliary coil and including a common emitter amplifier portion including a common emitter amplifier connected to the auxiliary winding, wherein the voltage regulator is configured and arranged to regulate a voltage supplied by the auxiliary winding to a desired voltage for application to the power factor correction controller.   
     
     
         2 . The circuit of  claim 1 , wherein the boost portion comprises a charge pump. 
     
     
         3 . The circuit of  claim 1 , wherein the boost portion is configured and arranged in a critical conduction mode topology. 
     
     
         4 . The circuit of  claim 1 , wherein the voltage regulator further comprises a Zener diode connected to the base and the emitter of the common emitter amplifier transistor. 
     
     
         5 . The circuit of  claim 1 , wherein the voltage regulator further comprises a diode coupled in series between the auxiliary coil and the common emitter amplifier. 
     
     
         6 . The circuit of  claim 5 , wherein the voltage regulator further comprises a storage capacitor coupled between the diode and ground. 
     
     
         7 . 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 400 V DC. 
     
     
         8 . The circuit of  claim 1 , wherein the PFC controller is a NCP1606 controller. 
     
     
         9 . A lighting apparatus driver circuit comprising:
 a driver control circuit including a driver controller;   a comparator circuit including a comparator, wherein the comparator is connected to the driver control circuit; and   a voltage regulator connected to the comparator circuit;   wherein the driver circuit is configured and arranged to regulate the current supplied to an electrical load at a nominal current plus or minus about 2%.   
     
     
         10 . The driver circuit of  claim 9 , wherein the voltage regulator comprises a shunt regulator. 
     
     
         11 . The driver circuit of  claim 9 , wherein the comparator comprises a single differential comparator. 
     
     
         12 . The driver circuit of  claim 9 , further comprising a diode configured and arranged to provide a return path for load/inductor current during a transistor switch off time. 
     
     
         13 . The driver circuit of  claim 12 , wherein the diode comprises a silicon carbide Schottky diode. 
     
     
         14 . The driver circuit of  claim 9 , further comprising an input configured and arranged to received power with a voltage of about 400 V. 
     
     
         15 . The driver circuit of  claim 14 , further comprising a capacitor bank configured between the input and ground. 
     
     
         16 . The driver circuit of  claim 9 , wherein the comparator is connected to a current sensing input of the driver controller. 
     
     
         17 . The driver circuit of  claim 16 , wherein the driver controller is a HV9910 controller. 
     
     
         18 . A lighting power supply comprising:
 (i) a PFC stage including:
 a EMI filter configured and arranged to receive a 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; 
 a boost circuit connected to the rectifier and including a PFC controller and a PFC coil with an auxiliary winding, 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; and 
 a voltage regulator connected to the auxiliary coil and including a common emitter amplifier portion including a common emitter amplifier connected to the auxiliary winding, wherein the voltage regulator is configured and arranged to regulate a voltage supplied by the auxiliary winding to a desired voltage for application to the power factor correction controller; 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 driver controller.   
     
     
         19 . The power supply of  claim 18 , wherein the driver stage comprises:
 a driver control circuit including a driver controller;   a comparator circuit including a comparator, wherein the comparator is connected to the driver control circuit; and   a voltage regulator connected to the comparator circuit;   wherein the driver circuit is configured and arranged to regulate the current supplied to an electrical load at a nominal current plus or minus about 2%.   
     
     
         20 . The power supply of  claim 19 , wherein the voltage regulator comprises a shunt regulator. 
     
     
         21 . The power supply of  claim 19 , wherein the comparator comprises a single differential comparator. 
     
     
         22 . The power supply of  claim 19 , further comprising a diode configured and arranged to provide a return path for load/inductor current during a transistor switch off time. 
     
     
         23 . The power supply of  claim 22 , wherein the diode comprises a silicon carbide Schottky diode. 
     
     
         24 . The power supply of  claim 19 , further comprising an input configured and arranged to received power with a voltage of about 400 V. 
     
     
         25 . The power supply of  claim 24 , further comprising a capacitor bank configured between the input and ground. 
     
     
         26 . The power supply of  claim 19 , wherein the comparator is connected to a current sensing input of the driver controller. 
     
     
         27 . The power supply of  claim 26 , wherein the driver controller is a HV9910 controller. 
     
     
         28 . The power supply of  claim 19 , wherein the PFC stage and the driver stage are configured and arranged on a common circuit board. 
     
     
         29 . The power supply of  claim 19 , wherein the boost portion comprises a charge pump. 
     
     
         30 . The power supply of  claim 19 , wherein the boost portion is configured and arranged in a critical conduction mode topology. 
     
     
         31 . The power supply of  claim 19 , wherein the voltage regulator further comprises a Zener diode connected to the base and the emitter of the common emitter amplifier transistor. 
     
     
         32 . The power supply of  claim 19 , wherein the voltage regulator further comprises a diode coupled in series between the auxiliary coil and the common emitter amplifier. 
     
     
         33 . The supply of  claim 32 , wherein the voltage regulator further comprises a storage capacitor coupled between the diode and ground. 
     
     
         34 . The power supply of  claim 19 , 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 400 V DC. 
     
     
         35 . The power supply of  claim 19 , wherein the PFC controller is a NCP1606 controller. 
     
     
         36 . A lighting apparatus comprising:
 (i) a PFC stage including:
 a EMI filter configured and arranged to receive a 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; 
 a boost circuit connected to the rectifier and including a PFC controller and a PFC coil with an auxiliary winding, 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; and 
 a voltage regulator connected to the auxiliary coil and including a common emitter amplifier portion including a common emitter amplifier connected to the auxiliary winding, wherein the voltage regulator is configured and arranged to regulate a voltage supplied by the auxiliary winding to a desired voltage for application to the power factor correction controller; and 
   (ii) a driver circuit including 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 driver controller; and   (iii) one or more lighting elements configured and arranged to receive power from the driver circuit.   
     
     
         37 . The lighting apparatus of  claim 36 , wherein the driver stage comprises:
 a driver control circuit including a driver controller;   a comparator circuit including a comparator, wherein the comparator is connected to the driver control circuit; and   a voltage regulator connected to the comparator circuit;   wherein the driver circuit is configured and arranged to regulate the current supplied to an electrical load at a nominal current plus or minus about 2%.   
     
     
         38 . The lighting apparatus of  claim 36 , wherein the one or more lighting elements comprise one or more LEDs. 
     
     
         39 . The lighting apparatus of  claim 38 , wherein the one or more LEDs comprise a plurality of LEDs connected in a series configuration.