Opto-coupler Plug
€2.50 - €8.50The Opto-coupler Plug is a small board containing a dual opto-coupler. It can be used to detect the presence of low DC voltages (a few dozen volts) and currents (milliamps) without creating a direct electrical connection to any other circuits.
Both input circuits consist of a built-in LED which must be driven with ≈ 3 .. 55 mA of current. Two 1 kΩ series resistors are included, which allow using this board with 3 .. 12 V DC sources. Other resistor values can be used for higher or lower voltages.
In theory, this plug could be used to detect AC mains power, when part of a suitable circuit. In practice, you should only consider this if you know exactly what you're doing, and have taken all the necessary safety precautions. High voltages can be lethal - proceed at your own risk!
The PCB only variant contains just the board for the Opto-coupler Plug. No parts, no headers.
As connectors you can use a Plug Headers set with 10 male and 10 female 6-pin headers, which makes it easy to connect multiple plugs and JeeNodes in a “standard” way. Or you can solder the board directly in place for more permanent use.
The documentation and full design details are freely available.
Update - the new v2 board can now also be used as dual opto-coupled output interface, where each channel acts as a (polarized) switch, based on the built-in photo transistor. The output drive current is limited to 60 mA max.