This circuit with unijunction transistors was found in a documentation from the 80's. The trigger times of the SCRs depend on the capacitors and are adjusted in the 5M (4M7) potentiometers.
This circuit was found in an English publication from the 80's. It triggers a buzzer (with...
The SN72741 integrated circuit is nothing more than the version of Texas Instruments of the known...
This simple circuit connects in external battery to a load when the AC Power line fails. S1 can be...