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Thread: AC Volt and Amp Meter with a 0-5VDC linear output

  1. #1
    ElmVideo Newbie
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    Default AC Volt and Amp Meter with a 0-5VDC linear output

    Hi,
    I want to build a 120VAC Voltmeter AND a 0 - 30A AC Ampmeter (safely isolated and seperatley, not a 'power meter') that will give a 0 - 5 VDC linear output. For example, a 120VAC RMS input voltage would give me a 1.2VDC (very low ripple) output. A 3.2A AC current would give me a .32 VDC output (very low ripple). Also I want to use my existing power supply that is a single supply, I can regulate it to +15V if need be. I have tried many experiments but all produce poor results, and just interfacing the high voltage line is a problem. Any help would be appreciated, Thanks, Eric


  2. #2
    ljcox Good ljcox Good
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    You need to use op amnps with a gain of 10. There have been plenty of posts recently about op amps.

    As for isolating the current, you could use a current transformer. There is a recent post on this also.

    Len

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