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Thread: Unknown Motor Speed Control I think?

  1. #11
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    It's very similar to the Bridgeport 6F of the same era. If so.. take care... the DC buss is -170v w.r.t. ground. Clipping on a scope probe ground without an isolation transformer will wake you up - don't ask how I know

  2. #12
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    Quote Originally Posted by lakeside53 View Post
    It's very similar to the Bridgeport 6F of the same era. If so.. take care... the DC buss is -170v w.r.t. ground. Clipping on a scope probe ground without an isolation transformer will wake you up - don't ask how I know
    It's worse than that....

    The thing doesn't really have a high voltage DC bus, because it does not need it, the HV is just for the motor, so it gets rectified, but not filtered, the motor does not care. There is a low voltage DC bus supplied presumably by the transformer.

    BUT, every bit if the circuitry in there is at mains voltage, so you cannot use a regular 'scope to look at anything unless you have an isolating transformer on the input of the control (or use two channels as a differential input).
    1601

    Keep eye on ball.
    Hashim Khan

  3. #13
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    Incidentally the manual in PDF is out there via Google includes complete schematic.
    Set up and troubles shooting.
    Max.

  4. #14
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    Unfortunately I am sharp as a dull pencil when it comes to electronics,there were a bunch of Penta Drives in the same lot as in pic.

  5. #15
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    Those are nice drives, include reversing and dynamic, four quadrant braking. Albeit they are also SCR bridge drives.
    Max.

  6. #16
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    Yuck!!! Analog electronics!

  7. #17
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    Quote Originally Posted by RB211 View Post
    Yuck!!! Analog electronics!
    What is out there to run motor this size forward& reverse and variable speed that won't brake the bank.

  8. #18
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    KB controllers both SCR as you show and PMW, T.M. MC60 or preferably the MC2100. All on Ebay.
    The one you show in post #14 has all you require, reverse etc, the others I cited you need to implement direction control.
    Depends on the application, but in most cases you want to remove the flywheel.
    Max.

  9. #19
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    Quote Originally Posted by MaxHeadRoom View Post
    KB controllers both SCR as you show and PMW, T.M. MC60 or preferably the MC2100. All on Ebay.
    The one you show in post #14 has all you require, reverse etc, the others I cited you need to implement direction control.
    Depends on the application, but in most cases you want to remove the flywheel.
    Max.
    That Penta is only rated for 10.2 amps,that 3 hp is 26 amps.I have a MC 60 which is also shy on amp rating.

  10. #20
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    What was the original TM plugged into? A 30amp socket!
    Max.

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