Peter's electronic projects

Audio-video switch

description

This is an 8-input x-output audio/video switch module to be controlled from a computer, for example from the parallel port. Each audio/video output can be switched to any of the 8 inputs, separately. One module drives one audio/video output and has a 34-pin connector to plug into the system interface.You can use video OPA-s on the 4051 output instead. Note that you can get full integrated video multiplexers from Maxim.

Schematic diagram

WARNING: the drawing has been updated and

the video amplifier on the 4051 output is corrected
the amplifier component values are shown

The circuit uses 5VDC as VCC and -7VDC as VEE. The video inputs are terminated to GND by 75 ohm resistors.