Rectifier-inverter circuit with low harmonic feedback, particularly for operation of fluorescent lamps
US4959591A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 2, 1989 |
| Grant date | Sep 25, 1990 |
| Priority date | — |
| Expiry date | Aug 2, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
To ensure synchronous operation of push-pull connected oscillator transistors (T1, T2), receiving rectified power via a rectifier (GL) from a power network (U), in which the circuit includes an elevated voltage maintenance or step-up converter circuit having a choke (L2), a switching transistor (T3) and a diode - capacitor circuit (D5, C2), the switching transistor (T3) is controlled from the same source of control voltage as the push-pull connected oscillator transistors (T1, T2), for example by coupling the base of the switching transistor (T3) to receive control energy from a feedback coil (RK3) of a feedback transformer (RK1, RK2, RK3) also supplying feedback energy to the push-pull oscillator transistors (T1, T2). The switching transistor (T3) can be controlled by a controllable resistor (R2) connected to its base, which may receive a control voltage through a control amplifier (FIG. 3: RV) representative of voltage levels in the circuit. A further transistor (T4) can be connected serially between the rectifier (GL) and the choke (L2) of the step-up converter circuit which improves approximation of sinusoidal wave form and voltage level maintenance of the circuit, the further …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.