Bridge Rectifier

Discussion in 'General Electronics Chat' started by mbxs3, Nov 2, 2010.

  1. mbxs3

    Thread Starter Active Member

    Oct 14, 2009
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    Hi, I have a question about the use of a bridge rectifier. We have a vacuum that runs off of 120vac/60hHz power supply. The motor inside the vacuum is the motor seen here...

    http://www.grainger.com/Grainger/AMETEK-LAMB-ACDC-Vacuum-Motor-2M195

    Also incorporated into the circuit(internal to vacuum) is a bridge rectifier. The one used can be seen here...

    http://www.grainger.com/Grainger/AMETEK-LAMB-ACDC-Vacuum-Motor-2M195

    My question is what purpose does this rectifier serve? The motor is rated at 120vac/50-60Hz which it seems to me would be available from the power supply when it gets plugged in. Any clarification would be greatly appreciated. Thank you.
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    U gave the same link twice.
    I do not see any bridges.
     
  3. mbxs3

    Thread Starter Active Member

    Oct 14, 2009
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  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    Does the vacuum have a two speed setting or switches.
     
  5. marshallf3

    Well-Known Member

    Jul 26, 2010
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    While a lot of the motors used in vacuum cleaners are capable of AC or DC operation some are DC only.
     
  6. mbxs3

    Thread Starter Active Member

    Oct 14, 2009
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    @Kermit2: The vacuum is only one speed and the only other component in the circuit, other than the things already mentioned, is an on/off switch.

    @marshallf3: If the bridge rectifier in this vacuum became defective, could I completely bypass it and run the motor off the 120vac/60Hz outlet?
     
  7. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    From the motor description: "AC/DC Vacuum Motor, ...", which implies to me that the motor itself is a DC motor (hence the internal bridge rectifier). Thus, I wouldn't recommend bypassing the bridge rectifier. At best, I suspect the motor will sit there and buzzzzz.
     
  8. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    I donno.. could be a universal motor, but it's hard to say without seeing the wiring for the field and armature
     
  9. jatinah

    New Member

    Jul 26, 2010
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    I recently repaired a vacuum which had a similar design scheme. There was a bridge rectifier in some shrink-tubing, which led down to the agitator brush at the base of the vacuum. The motor link shows a DC motor, with a "Brush Set". Most all AC motors won't use brushes, usually only dc motors. The Bridge is rated at 12A continous so the motor must be using the rectified DC from the bridge. No, don't bypass the bridge with AC, that would most likely smoke that motor.
     
    Last edited: Nov 3, 2010
  10. mbxs3

    Thread Starter Active Member

    Oct 14, 2009
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    Thanks for all of the input everyone.
     
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