There have been many different ideas presented for increasing the acoustic output of a piezo buzzer or ultrasonic transducer. Most of them involve rather complicated circuitry that drives up the total ...

A parallel circuit is way of connecting components on separate branches, so the current can take different routes around the circuit. The current is different in different parts of a parallel circuit.

The circuit presented here can be used for connecting two telephones in parallel and also as a 2-line intercom. Usually a single telephone is connected to a telephone line. If another telephone is ...