This is the old name given to flip-flops or biestable multivibrators. In fact, this is a 1967 Ferranti circuit, triggered by a light sensor.
This simple two-transistor FM transmitter was found in the November 1991 issue of Radio...
In fact, the maximum output current of this source depends on the transformer which can be 6, 7.5, 9...
This interesting manual circuit uses an SCR to switch a load on and off via pulses. The circuit was...