This circuit is from an American documentation from 1975. The single junction transistors can be 2N2646 and the signal must be applied to the input of a good amplifier.
Found in 1967 Raytheon documentation, this circuit uses a company coupler consisting of a lamp and...
In a modern version this circuit can use an LED in series with a resistor in place of the lamp. The...
This circuit, when triggered, locks, and remains so until the source is switched off for a moment or...