We found this circuit in a French documentation from the 80's. The components used are still common and the circuit can generate signals from 10 Hz to 100 kHz.
We found this circuit in a Popular Electronics of the 90s. The MOSFET can be of any type,...
In fact, the correct name would be a hearing aid amplifier. However, we use the name of the...
This circuit controls a relay causing it to open and close its contacts at a speed that depends on the...