Wiring question.

[mac dillard]

I am going to use a remote switch to operate a switching relay in a Real McTube II. The coil wil be 12VDC. I intend to install a 1/4" phone jack in each for the connections and use quitar cable for the connection. This means that I will be using the center wire and the outside shield to conduct the 12VDC. Anyone see a problem using the quitar cable this way?

[Peter Snowberg]

A 1/4" speaker cable would be better, but for the tiny power a signal relay takes a guitar cable should work just fine. I would wire it as...

+12V to relay +
relay - to control jack tip connection
control jack sleeve connection to ground

If you add a bright LED with a big series resistor in parallel with your switch, the LED will light when the switch is open. Depending on how you wire the relay, the LED will indicate either engaged or bypass.

Be sure to also add a power diode (ideally 1N4004 to 1N4007) in parallel with the coil, but with the anode connected to the - and the cathode on the + of the coil. That diode will eat the high voltage pulse generated when you switch the coil off.

[mac dillard]

Thanks Peter. Hadn't thought about the diode in parallel with the coil...apreciate it..