This circuit takes advantage of the hysteresis of a relay to provide a latching effect. The circuit acts as a trigger and the components must be according to the used relay.
This circuit uses two transistors and can be powered by just two small batteries. The frequency is given...
This circuit was found in the February 1985 issue of Radio Electronics magazine. It is based on an...
This circuit from Ferranti was released in 1969. It makes use of the company's transistors that admit...