High Impedance Voltmeter LM358


Posted on Jan 31, 2013

This circuit is designed to provide an inexpensive way to to create a High Impedance Voltmeter while making use of an inexpensive analog or digital multimeter. When measuring voltages in high resistance circuits the resistance of the voltmeter itself has an effect on the circuit. For example if the voltage across a 1 megohm resistor is measured with a voltmeter that has an internal resistance of 1 megohm then the total resistance in that part of the circuit is effectively halved (two 1 M resistors in parallel = 500K ohms).


High Impedance Voltmeter LM358
Click here to download the full size of the above Circuit.

In another example; If a voltmeter with a 1 megohm resistance is placed in series with a 1 megohm resistance there will in effect be two - 1 megohm resistances in series, the resistor in the circuit and the resistance of the voltmeter. Under these conditi




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Simple Transistor Reflex Receivers
    Voltage Regulator
    Light-modulator
    NiCd NiMH Battery Charger
    Single Differential Input Adapter for Digital Voltmeter
    fm oscillator with bly87
    Infrared Detector Circuit with PID20
    RFID Readers for the HDX Protocol
    Four independent charging single battery automatic charger circuit



    Top