A small but very useful circuit, which can handle a signal, which can carry in four points. Its main application is to carry the signals of four cameras to one display for better monitoring. The circuit can be used in other applications like audio signals, alarm systems, sequential lighting and many other cases, which require a regular control selection. In a small PCB the well-known micro controller PIC12F675 drives four relays with LED indications. One can select the desired channel manually by two small push buttons switches one for left and one for the right selection. Another push button switch if for automatic regular channel selection every five seconds. The regulator and filtering stage are on board.
Working voltage: 9 VAC.
Consumption: 50mA (with one relay and one LED ON)