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.
PIC16F15386 Family with CIPs Uses MPLAB® Code Configurator for Quick Development The PIC16F15386...
This simple Philips circuit from the 1960s can use any general-purpose transistor. The signal is...
This circuit is from a 1966 American documentation. The circuit uses a photo-FET, an unusual...