These circuits were found in Exar documentation from the 90s. The circuits use both a small speaker and a piezoelectric transducer. The integrated circuit is not common today.
The load on this amplifier is 8-ohm. We found the circuit in a 1972 Motorola amplifier manual. The...
This circuit can control a heating element with a current of up to 5 A. The integrated circuit must...
We found this circuit in a 2003 publication. The indicated coil is for capturing the signals in an...