| 摘要 |
PURPOSE:To prevent the multifunction effected by the dispersion in the cut-off voltage of cathode ray tube, by connecting the bias set circuit in series with the load resistor of the video output transistor. CONSTITUTION:Between the collector R11 of red signal R video output transistor Q11 and DC power supply E1, the bias set circuit consisting of the transistor Q12, variable resistor VR13, resistor R13 and bypass capacitor C11 is connected. The transistor Q12 is constituted as the emitter follower, and the potential of the cathode KR when the cathode ray tube CRT is cut off, is set with the variable resistor VR13. The emitter current of the video output transistor Q11 is decided with the variable resistor VR12 and resistor R12 and it is not effected by the said bias set circuit. The same constitution is applied to other signals green G and blue B as well. |
