Found in an old Radio Electronics, this circuit applies to frequency meters for frequencies up to 100 MHz. The input impedance is in the order of 1 M ohm.
This circuit was obtained in an old American documentation serving only for general purpose NPN...
This circuit can measure frequencies up to 10 kHz using a digital multimeter or the 7107. The...
This is a traditional CMOS configuration found in other articles in this section and on this...