This circuit activates a buzzer when the voltage applied to the input falls below a preset value in R1. The circuit is from an 80's American documentation.
This digital pulse counter offers an LED indication. Its maximum frequency is of the order of 5...
This 1960s Signalite circuit uses two SCRs to achieve full wave control. The trigger elements are...
This circuit was obtained from a Popular Electronics. The component is a UJT. The circuit has an...