Frequency meters measure repetitions per unit of time (frequency) and display it using a needle or graphic pointer. Industrial frequency meters are used in radio frequency (RF) and microwave ...

This project demonstrates an Arduino-powered wireless frequency meter that can measure the frequency of sinusoidal AC transmissions ranging from 50Hz to 3kHz. Figures 1 and 2 show prototype ...

A while back we saw a logic clock that used the alternating current frequency from the power grid ... [Doug] pulls a signal from the 9V AC power before it hits the bridge rectifier, using a ...