[GreenKeys] gears

[Ralph Mowery]

It might be worth a try with the modern VFD units.  Where I worked we put in lots of VFDs from 1/2 HP to 200 hp motors.  Most smaller ones  would run down to 25% speed or so.  We also burnt up some 30 HP motors with the eairler drives.  The motor did not turn fast enough to cool it.  On some motors we put an extra fan to blow air across it or tapped in to the air conditioner ducts and sent cool air across them.

The newer drives put out very odd pulses when looked at by an oscilliscope.  I don't even see how the motors run, but they do.

We were using drives like this at the time.  They are obsolete now and newer drives are out.
http://www.yaskawa.com/site/Products.nsf/products/Industrial%20AC%20Drives~V7.html



  ----- Original Message ----- 
  From: WA5CAB at cs.com 
  To: greenkeys at mailman.qth.net 
  Sent: Sunday, February 03, 2013 10:44 PM
  Subject: Re: [GreenKeys] gears


  I don't think so but your best chance of success would be to gear it for 75 speed if you wanted to hit 100, 67 and 60.

  However, do not try to run either a 15 or a 14 typing unit (with or without perforator) at 100 speed.  

  In a message dated 02/03/2013 21:11:16 PM Central Standard Time, nerd at verizon.net writes: 

    I know this might be a little bit blasphemous here, but is there any reason a 
    synchronous motor TTY couldn't be run with a cheap VFD to make it able to run at 
    any arbitrary speed?  So a 67 WPM machine could be made to run at 100, or a 100 
    WPM machine at 60?

    Peter
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