An oscillator whose frequency is determined by the value of a voltage, current, or power.

An oscillaory is a mechanical or electronic device that produces a back-and-forth periodic motion.

A pendulum is a simple mechanical oscillator that swings with a constant amplitude, requiring the addition of energy at each swing only to compensate for the energy lost because of air resistance or friction.

In electronic oscillators, electrons oscillate with a constant period and also require the addition of energy to replace energy loss.

Electronic oscillators are used to generate alternating current and high-frequency currents for carrier waves in radio broadcasting.