Drive circuit for a television deflection output transistor
US4177393A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 20, 1977 |
| Grant date | Dec 4, 1979 |
| Priority date | — |
| Expiry date | Dec 20, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K4/64
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A drive circuit for a television deflection output transistor includes a drive transformer, the secondary winding of which is coupled across the base-emitter junction of the output transistor. A first end of the primary winding of the drive transformer is coupled to a driver transistor which is switched at the deflection rate. The second end of the primary winding is coupled to a first capacitor charged through a first charging resistance from a first voltage source, the magnitude of which is determined by the charge storage in the base region of the output transistor, and its current gain. The second end of the primary winding is also coupled through a diode to a second capacitor charged through a second resistor from a second voltage source. The magnitude of the second voltage source is selected at a value significantly lower than that of the first voltage source, which value is established based upon considerations of the forward base-emitter drive current required by the output transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.