| 摘要 |
PURPOSE:To ensure an extremely simple control for the white balance or the like, by constituting a circuit so as to execute both the drive and bias controls of a color output independently with each variable resistance. CONSTITUTION:The resistances R11-R13 are put between the emitter and the earth of each of color outout amplifying transistors TRQ11, Q21 and Q31, and at the same time color drive controlling variable resistances VR11, VR21 and VR31 are inserted between th points of connection between the emitters and voltage dividing resistances. Thus a bridge circuit is obtained. Then the DC voltage set by color bias controlling variable resistances VR12, VR22 and VR32 and between the collectors and earths of TRQ11, Q21 and Q31. AS a result, the working bias point of a cathode electrode KR of a CRT can be varied without changing the driving amount to the CRT by controlling e.g. the resistance VR12. And the resistance VR11 is controlled to vary only the driving amount R. |
