AF counter circuits


Posted on Feb 6, 2014

A digital AF (audio frequency) counter can be constructed with only few components by using a single 7226B IC from Intensil as shown in the diagram. The upper frequency limit of this circuit is 9 MHz. The four important functions in the frequency counter are: pulse processing, multipying, counting with timebase, and display. The input signal is co


AF counter circuits
Click here to download the full size of the above Circuit.

nverted to a squarewave pulse by the input circuitry. The input circuitry is protected up to 50 Vrms. Its impedance is around 2 megaohms. The signal is then multiplied by a factor of 100. The counting process is done by the IC 7226B. This IC integrates the following circuits: oscillator with timebase; gating circuitry; counter stages; and a 7-segment display driver with multiplexer. Switch S1 enables one to choose between the original frequency or the one multiplied by 100. Multiplying the input by 100 enables the frequency range 5 Hz to 5 kHz to be displayed. S2 selects the measuring range while S3 is the power supply switch.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Photomultiplier output-gating circuit
    4.5Mhz notch filter
    120Ac Shimmering Light Circuit
    Motor Generator Stepper
    power supply Inductive choke with bypass capacitors
    3 Band Graphic Equalizer
    Harmonic Generator With Single Opamp
    555 audio oscillator
    Feld-Hell electronic circuitry and schematics
    MRC DCC Decoder
    Digital delay circuit lamp circuit 2
    Turning gear from idling stop circuit diagram
    By the actual application circuit composed of a color picture tube with TDA6103Q
    Square transform circuit diagram
    EMR4.0 application circuit
    Tone selector circuit



    Top