This circuit produces a pulse when the voltage in the regulator exceeds a certain value depending on the components. PUT is not a common component today. The circuit is from a 1970 EEE.
We found this circuit in an American documentation from the 60's. The transistors are made of...
The accuracy of this circuit depends on adjustments made with capacitors of small tolerances of known...
The figure shows how to implement an OR function with two inputs, using a relay. The relay...