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EEVblog #1334 – Mystery Dumpster Teardown

Mystery dumpster teardown time! With the most amazing mechanical mains power switch you’ll ever see! ...

13 comments

  1. Those extra no connect terminals could be used to sense the phase voltages during meter verification. Current probes clamped around the wiring and phase voltages via banana plugs goes to a calibrated test tool. That tool also reads out the measured data from the meter via serial port or the blinking LED.

  2. Niklas’ right,
    Here’s the use of the little “no connect” pins:
    http://www.youtube.com/watch?v=2uS0gnyMzB8

    cheers 😉

    • That was an interesting video but it took a long time to say that:
      For calibration purpose the voltage sense is separated from the mains. This allow the meters to be calibrated with high current at low voltage and high voltage a low current

      This make since. There is little need to calibrate the meters using kilowatts of power when what you are calibrating is it’s ability to measure the volts and the amps. There is no reason the samples must be provided by the same wire.

  3. I be interested to see it powered up

    good teardown

  4. The two leds you mention at 10:18 look like an IR led+phototransistor pair used for IR communications with an external reader/programmer through that round window on the case.

    • Yes your spot on there, I was going to make such comment myself.
      Dave bit of a simple oversight there I believe? that circular window with what I’m guessing is a magnetic surround is a dead give away.
      I some time over look stuff too 🙂

  5. Interesting system. I wonder why the diodes on the board by where the netral is shunted are not arranged in a nice looking way (24:07). Is there some type of protection or efficiency this provides?

    • It is probably related to clearance and creepage distances in combination with shortest trace length possible. Like spokes on an old wheel.

  6. Hi Dave,
    How about doing a video where you measure the EMF coming from a working smart meter over a 24 period. The power companies claim it’s minimal, but it would be nice to see. Thanks.

    • I won’t fuel the paranoia.

      • There’s not much there over a plain old analog meter. Sure there’s a bit of fancy dandy digital electronics, but they’re low power electronics and the AC measurement board dwarfs it (as does the house wiring).

        The only thing that emits any significant form of EMF is the GSM module. Which is basically a cellphone.

        So in the end, the “EMF ARE KILLING ME!” folks are complaining about a cellphone which they all probably have and use constantly. (Nevermind that there’s only one real instance of EMF sensitivity – and given modern life, the poor guy has to live in the country where the nearest road is miles away (a car’s ignition system generates enough to bother him, you’d need to go with an ancient all-mechanical diesel), the reporter had to use a manual film camera (ditto) and wear mechanical watches. He got it through a lifetime of working on high-powered RF. Oh yeah, and he has no electricity in his house, for obvious reasons. And not for lack of trying – he actually has an special shielded suit that worked for a few years.

  7. Hi, I want to know If anyone can help me to find a terminal block like in this video for a proyect. Thanks for your help and great review!

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