Re: [ATM] DC Motor for grinding machine question

[Ken Hunter <atm_ken_hunter@yahoo.com>]

Rod...
   
  re: Controlling a DC motor with a Variac.
   
  You will need a bridge rectifier that can handle twice the full load motor current to change the AC to DC, a filter capacitor to smooth out the operation and most importantly, an isolation transformer rated for the full load power of the motor if you are using a variac to control the speed. 
   
  A Variac does not have circuit isolation as all connections are connected directly or indirectly to the electrical supply. Not the kind of thing you want in a wet location without some sort of protection for the operator.
   
  There are also "Chopper type" speed controls you can buy... I was looking at one yesterday at one of the local Goodwill stores. It's embedded in a $12.99 treadmill which is a good source for Grinding machine motors and controllers BTW...
   
  or... You can search eBay. There's usually a bunch of them there.
   
  Happy Grinding!
   
  Ken Hunter
  

Rod Brackenridge <rjbr@gawab.com> wrote:
  Is there any circuitry I need between it and a DC
motor?

Thanks,

Rod.


 
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