I first heard about and took a look at Relay, a screenless phone for kids back in 2018. The small walkie-talkie device is incredibly simple and easy to use and made it easy to communicate with my own ...

This circuit allows an SPST momentary pushbutton to act as a push-on push-off switch, using a DPDT latching (bi-stable) relay. It was originally intended to allow a single pushbutton switch on the ...