Switched mode vertical deflection system and control circuit
US4999549A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 27, 1990 |
| Grant date | Mar 12, 1991 |
| Priority date | — |
| Expiry date | Apr 27, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K4/835
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A deflection system comprises: a signal generator, an amplifier stage, a negative feedback path and a vertical rate waveform generator. The signal generator is coupled to a source of flyback pulses for developing from energy in the flyback pulses a horizontal rate drive signal having a predetermined and substantially constant DC voltage reference level. The amplifier has a first input coupled for receiving the horizontal rate drive signal and an output coupled to a deflection coil. The amplifier output has a DC voltage reference level corresponding to the DC reference level of the horizonatl rate drive signal. A DC feedback signal on the negative feedback path is related to deflection current. The feedback path is coupled between the coil and a second input of the amplifier. The vertical rate waveform is also coupled to the second input of the amplifier for modulating the horizontal rate drive signal. The output of the amplifier is a pulse width modulated control signal for a switching element, for example a silicon controlled rectifier. In a switched mode vertical deflection system, the horizontal rate drive signal and the vertical rate waveform are ramp signals and the flyback pu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.