A frequency meter circuit diagram composed of CD4046

CD4046 is a general-purpose CMOS phase-locked loop integrated circuit. It is characterized by a wide power supply voltage range (3V-18V), high input impedance (about 100MΩ), and low dynamic power consumption. The power consumption is only 600μW when the center frequency f0 is 10kHz. , is a micro-power device.

The frequency meter uses the needle to indicate the level of the frequency being measured. R1 is composed of a 47k fixed resistor and a 51k potentiometer connected in series. R4, R5 and C4 form a low-pass filter. R3 is connected in series with the meter M and serves as the load of the source follower. R3 is also used to adjust the full-scale current of the meter. There is a large capacitor of 100LF on the meter head, which is used to eliminate the jitter of the meter needle at low frequencies. The measurement range of this frequency meter is 20Hz~1kHz.

The following is a frequency meter circuit diagram composed of CD4046.