Vacuum-Tube Voltmeters


Posted on Feb 5, 2014

Vacuum-tube or electronic voltmeters make use of some of the unique characteristics of electron tubes, and so are available in many types. They are available for measuring direct, rms, average or peak voltages. Of the many types available, only the simplest and possibly the most commonly used type for measuring rms values of alternating voltages will be described here.


Vacuum-Tube Voltmeters
Click here to download the full size of the above Circuit.

The chief advantages of the electronic voltmeter are its high input impedance, wide frequency range, and sensitivity. Because of its high impedance it does not divert enough current to disturb the circuit to which it is connected. Fig. 28-28 shows a simplified diagram of one type of electronic voltmeter. It uses a simple evacuated triode as a detector, as described in Chapter 27. The milliammeter in the plate circuit is calibrated in terms of rms volts applied to the grid. This type of voltmeter is available with a built-in rectifier and filter, so that it may be connected to a standard 120-volt, 60-cycle supply.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    1watt AM/CW 10-meter band transmitter
    Circuit DIY of the inverter (picture and text is explained in detail)
    pic PIC16f877A resets due to external noise
    Micore Reader IC Family Directly Matched Antenna Design
    Programming the AVR Microcontroller with GCC
    Measuring the differential pressure sensing bridge circuit diagram
    GPS RF front-end circuit MX2740 circuit



    Top