Based on NE555 this circuit turns on and off the IC output by a momentary switch. In other words it works as a mechanical latching relay, but the circuit backs to the start condition when you switch ...

When we first saw [Maarten Tromp]’s article about a “momentary latching switch” for guitar effects pedals, we have to admit to being a bit confused. When it comes to push-button switches, “momentary” ...