This circuit limits the intensity of an audio signal from a control voltage. The circuit is from a 90’s Radio Electronics. The coupler is a type that uses LDR.
A narrow range of frequencies around 1 kHz is rejected by the high Q filter shown in the figure,...
This simple converter does not use a transformer and the transistor can be the BD135 for currents up...
This is a circuit from the time when some still called the transistor a crystal triode. It...