Found in a 1967 General Electric SCR manual, this circuit triggers in case of excess current, causing the fuse to blow or a circuit breaker to open. The components are from the era.
Using an operational amplifier, the figure shows how to convert the waveform to low frequency...
This is the power step of the previous circuit. Output transistors must be mounted on good heat...
The UM3562 integrated circuit (not very easy to find) synthesizes three types of sound that...