Found in a 90s Popular Electronics, this circuit triggers a load from the audio signal applied to its input. The controlled load depends on the MOSFET.
We found this circuit with transistors in a Philips documentation from 1968. The double transistor...
This circuit is from a 1965 General Electric manual. It uses components from the time that admit...
Obtained from a 1996 documentation, this circuit uses common components and has a voltage gain of 200...