


So a 2nd circuit with a normal relay can be used to cut power (use the NC contacts on the 2nd circuit). To turn off a latching relay, power must be interrupted. As mentioned, a latching relay can be used so that a momentary touch activates the relay and it remains active.Alternatively, something like a penny glued to a plastic backing will do the job. The touch pad can be most easily made by cutting a small square of PCB material and then soldering on a single wire.Relay w/12V Coil, Contacts To Suit Applicationīoard, Wire, Small Metal Pad For Touch Pad Using a latching relay and two of these circuits, a simple two pad "touch on/touch off" arrangement can be made. As it uses only a few commonly available transistors and a 12V supply, it is ideal for hostile environments where mechanical switches would be damaged. It is designed to directly switch a relay to allow it to be used with large loads. Similar to the CMOS based Touch Switch also on this site, this transistor based touch switch can activate a load simply by the user touching a metal plate.
