Re: [PSUBS-MAILIST] PWM Controllers

[jbarlow@bjservices.ca]

Robin Williams does a bit on acronyms, Not PWM, FET, or SCR.  FET is
basically an electronic relay I believe.


Jay.



                                                                                                                                                
                      jbarlow@bjservices.ca                                                                                                     
                      Sent by:                          To:       personal_submersibles@psubs.org                                               
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                      s@psubs.org                       Subject:  Re: [PSUBS-MAILIST] PWM Controllers                                           
                                                                                                                                                
                                                                                                                                                
                      20/01/2003 07:43 PM                                                                                                       
                      Please respond to                                                                                                         
                      personal_submersibles                                                                                                     
                                                                                                                                                
                                                                                                                                                





FYI,

I have said for some time that the downfall of our civilization will be the
use of acronyms.  It is almost getting to point where people can't
understand each other.
  Is the end of communication the end of civilization??

LOL.  (-:  ......

I think PWM is "pulse width modulation" ??

The DC motor is turned on and off rapidly to reduce the power going to it
instead of using as resistor to run at less than full throttle. (though
electric motors don't actually have throttles)



Robin Williams does a good bit on it in Good Morning Vietnam.


MECHANICAL GUY ,

Jay.






                      John Rogers

                      <djohnndjinn@yahoo.com>           To:
personal_submersibles@psubs.org

                      Sent by:                          cc:

                      owner-personal_submersible        Subject:  Re:
[PSUBS-MAILIST] PWM Controllers
                      s@psubs.org



                      20/01/2003 07:27 PM

                      Please respond to

                      personal_submersibles







FET = field effect transistor


SCR = silicon controlled rectifier


--John


 "Dale A. Raby" <publisher@thegreenbayweb.com> wrote:
 Militarese translation:

 LT = Lieutenant
 MRE's = Meals Rejected by Ethiopians (US soldiers and sailors eat 'em
 though)
 AWOL = Absent WithOut Leave
 SOL = Shit Outa Luck

 Now... I'd kinda like to know what FET's SCR's etc are as well!

 On Mon, 2003-01-20 at 19:34, Chris Nugent wrote:
            Would someone mind yelling down to the little people and
       explaining what exactly FET's, SCR's, IGBT's ARE?  And perhaps a nod
       in the direction of where one can pick up the basics of what is
       being talked about?  My LT told me I had to help with the MRE's
       because the cook was AWOL, and if I don't figure this out I'll be
       SOL and my sub will be DOA.

           Thanks,

       Nuge

        Subscuba@aol.com wrote:
             At least, and a bridge is what I would go with. You would
             probably have to parallel several in each leg of the bridge to
             avoid dissipation problems.

             There are a number of ICs on the market to do the drive
             functions. I think ONSEMI has one. You would have to do the
             power stages. Layout of the power stages are the bear.

             I would suggest IXYS as a starting vendor for the FETs. I
             think their site is "WWW.IXYS.com" they are not the only
             vendor.

             Ken Martindale

                   One other note on the price issue you brought up,
                   though. A
                   reversible speed controller requires a FET H bridge,
                   which means
                   twice the FETs. A forward only could be made for $5.00.
                   A good
                   reversible would easily hit $10.00.





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 Dale A. Raby

 Editor/Publisher

 The Green Bay Web

 http://www.thegreenbayweb.com






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