This circuit is from an American documentation from the 90's. The SCR can be of any type and the diodes must have current according to the controlled motor.
We found this active crossover in a Radio Electronics magazine from June 1961. Note the different...
Found in Popular Electronics from the 90s, this circuit serves to indicate the output level of a...
If you are on an old PC that you use for experiments, control or other applications, this circuit is...