Video Amplifier


Posted on Feb 5, 2014

The video amplifier in the diagram is a well-known design. Simple, yet very useful, were it not for the ease with which the transistors can be damaged if the potentiometers (black level and signal amplitude) are in their extreme position. Fortunately, this can be obviated by the addition of two resistors. If in the diagram R3 and R4 were direct co


Video Amplifier
Click here to download the full size of the above Circuit.

nnections, as in the original design, and P1 were fully clockwise and P2 fully anticlockwise, such a large base current would flow through T1 that this transistor would give up the ghost. Moreover, with the wiper of P2 at earth level, the base current of T2 would be dangerously high. Resistors R3 and R4 are sufficient protection against such mishaps, since they limit the base currents to a level of not more than 5 mA. Shunt capacitor C4 prevents R4 having an adverse effect on the amplification.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Miniature High-Rate ESC with BEC and Brake
    HI-FI Stereo Encoder / Multiplexer
    Crossfeed Headphone Amplifier
    Phase indicator
    Rs232-to-cmos-line-receiver
    Remote-Controlled Telephone/Fax Machine Switch
    Arduino Calibration
    motor-control-microcontrollers-miscellaneous
    Metronome Circuit
    Preamp Protection
    Audio Electronics
    A three-alarm phase circuits
    Volume control circuit



    Top