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Testing electrical instruments, Help please.

Discussion in 'Technical Q&A' started by swift53, May 4, 2024.

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  1. swift53

    swift53 F1 Veteran
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    Alberto
    #1 swift53, May 4, 2024
    I have a bucket load of all sorts of electrical instruments,
    And I would like to know how make them swing from 0 to 100 (tach, speedo, temp, press, amps, etc.),
    and I will not harm them while doing this.
    The mechanical ones, no prob. with the old drill, easy.

    Any simple solution will be greatly appreciated. You tube has tons, but all (most) risky
    for my terrific lack of knowledge in this electrical field.

    Thank you all!
    Regards,
    Alberto
     
  2. Qavion

    Qavion F1 World Champ
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    #2 Qavion, May 4, 2024
    Inputs are highly individualised. Could be a voltage, a pulsed voltage, a resistance, a data signal, etc.. Sometimes increased resistance means higher needle deflection, sometimes lower needle deflection. Without a spec sheet for each instrument, you're flying blind. If you don't have spec sheets, then all you can do is compare the instrument to a known good one.

    What era/cars are your instruments from? Do you have any Ferrari part numbers?

    By the way, how do you know the speed of your drill?
     
  3. swift53

    swift53 F1 Veteran
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    #3 swift53, May 4, 2024
    Ian, Hello...

    Thank you for the input. Duly noted.

    My drill speed, is variable, I have many different drills, as well as speeds. Ratio is 1:4. Speed on Label, so if 1250 RPM x 4= 5K rpm
    Also have a lathe with digital speeds increments of 10 RPM.
    Alfa Romeo, Ferrari, BMW, etc. No numbers, and too many :)

    One thing in common, all gauges pre-1970.

    Regards,
    Alberto
     
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  4. Qavion

    Qavion F1 World Champ
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    #4 Qavion, May 4, 2024
    Ah, somewhat before my (professional) time. Probably best to look for markings on the back of them, including part numbers and Google them to see if any technical data is forthcoming.
     
  5. RedNeck

    RedNeck F1 World Champ
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    #5 RedNeck, May 4, 2024
    I'd be interested in knowing more about what you are trying to test...I would assume the gauges are run by stepper motors?
     
  6. wmuno

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    #6 wmuno, May 5, 2024
    Many Veglia analog temperature gauges use resistance for the negative lead to the gauge. That is, with 12 volts (nominal) to the gauge, grounding the negaive lead to the gauge should bring the pointer to full scale ( the maximum temerature on the dial). The accuracy of the gauge depends on the quality of the sensor that sends the ground to the gauge.
     
  7. swift53

    swift53 F1 Veteran
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    #7 swift53, May 5, 2024
    (tach, speedo, temp, press, amps, etc.),
     

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