This sound frequency meter circuit is simple to build and can be constructed in a portable format. In can measure frequencies with a minimum level of 10 mVrms and a maximum frequency of up to 100kHz.

The device is a simple, small, and cheap frequency meter with out any hard to find components to be able to measure frequencies up to 40 MHz while having below 1% errors. Most of the analog and ...

In many instrumentation systems, the ratio of two frequencies has more significance than the two individual frequencies. One such application is the ratiometric capacitive sensor. In this case, two ...