Abstract

A controller for phase control of an AC supply 501, 502 switches capacitors 503, 504, 505 into or out of circuit in parallel or in series with the AC supply to provide the required phase correction. The controller connects a bleed resistor 515 across the capacitors to discharge any remanent charge on the capacitors 503, 504, 505 when these are disconnected from the AC supply 501, 502, the controller including a bleed resistor connection switch 510, 514 powered from the remanent voltage across the capacitors.

IPC Classes  ?

• G05F 1/70 - Regulating power factorRegulating reactive current or power

Abstract

A bilateral switch derives internal power for the operation of the switch control circuitry from a converter powered by the input signal, whether the input is AC or DC, and also operates the internal voltage isolated circuits powered by this from the input signal. The internal circuitry operates a pair of similar FET switches switching power on and off between their drain connections, relying on a reverse protection diode across the FETs to allow passage of either AC current or DC current in either direction.

IPC Classes  ?

• H03K 17/785 - Electronic switching or gating, i.e. not by contact-making and -breaking characterised by the use of specified components by the use, as active elements, of opto-electronic devices, i.e. light-emitting and photoelectric devices electrically- or optically-coupled controlling field-effect transistor switches
• H03K 17/60 - Electronic switching or gating, i.e. not by contact-making and -breaking characterised by the use of specified components by the use, as active elements, of semiconductor devices the devices being bipolar transistors

Abstract

An active phase angle correction circuit which corrects the phase angle between voltage and current in an AC supply varies the capacitive loading of the AC mains to reduce the phase angle to near zero by detecting the phase angle, reactively and resistively loading the AC mains in steps until the phase angle is at a desired level close to zero, and then maintaining or incrementally adjusting the loading. The applied loading may be continuously switched in and out at a rate much greater than the mains supply frequency.

IPC Classes  ?

• G05F 1/00 - Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems

Abstract

A circuit to supply an AC voltage to a fluorescent lamp load from an AC supply converts the supply to DC, boosts the voltage in a converter and then drives an inverter from the smoothed boosted voltage in such a manner that the inverter will not start if the load is too low and the inverter frequency is almost constant. The power factor of the circuit is maintaining very close to unity.

IPC Classes  ?

• H05B 37/02 - Controlling
• H05B 41/02 - Circuit arrangements or apparatus for igniting or operating discharge lamps Details
• H05B 41/14 - Circuit arrangements

Abstract

An active phase angle correction circuit which corrects the phase angle between voltage and current in an AC supply varies the capacitive loading of the AC mains to reduce the phase angle to near zero by detecting the phase angle, reactively and resistively loading the AC mains in steps until the phase angle is at a desired level close to zero, and then maintaining or incrementally adjusting the loading. The applied loading may be continuously switched in and out at a rate much greater than the mains supply frequency.

IPC Classes  ?

• G05F 1/70 - Regulating power factorRegulating reactive current or power

Abstract

An active phase angle correction circuit which corrects the phase angle between voltage and current in an AC supply varies the capacitive loading of the AC mains to reduce the phase angle to near zero by detecting the phase angle, reactively and resistively loading the AC mains in steps until the phase angle is at a desired level close to zero, and then maintaining or incrementally adjusting the loading. The applied loading may be continuously switched in and out at a rate much greater than the mains supply frequency.

IPC Classes  ?

• G05F 1/70 - Regulating power factorRegulating reactive current or power
• H02J 3/18 - Arrangements for adjusting, eliminating or compensating reactive power in networks