This circuit was found in an old GE manual. It uses a thermocouple as a sensor. The SCR must be in accordance with the power of the controlled load.
The figure shows three circuits for using headphones in amplifiers with speakers that do not have...
This shield was found in an American documentation from the 70s. The operational amplifier is from...
This circuit generates signals of less than 10 Hz. We found it in a Popular Electronics from the...