Indicated for activation by microcontrollers, this circuit was found in the Radio Electronics magazine of December 1987. The MOSFET can be of any type according to the buzzer.
We found this circuit in a 1998 documentation. It is based entirely on relays that must have...
This traditional complementary symmetry circuit provides 20 W of rms power at a load of 8 ohms...
Assembled with SMD components this circuit can be very small. The range is a few tens of meters. We...