This timer with two unijunction transistors and one SCR was found in an American documentation from 1964. The unijunction transistors could be the 2N2646.
We find this circuit in a 1976 NASA handbook. The circuit can be designed based on current logical...
In the circuit shown in the figure when we press S1, capacitor C1 charges slowly, and with that it...
This circuit is from a 1968 Motorola power circuit manual. The circuit uses transistors of the...