Homebrew PCBs

I am interested in this also, if you don't mind sharing.

Thanks,

Roger

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of awakephd
Sent: Friday, April 30, 2010 07:38
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: Speed control for laminator motor

 

  

Richard, what kind of circuit do you have in mind for the PWM? If you're wanting to do something with discrete ICs rather than a
microprocessor, I put together a PWM controller that allows for variable frequency as well as variable pulse width (true PWM) -- and
it only requires 2 op-amps or comparators, so it can be made with a single chip (not counting the drive circuitry). This may be a
common design -- I may have re-invented the wheel! -- but I couldn't find anything like this when I was needing this circuit. I
specifically wanted something that generated true PWM, but allowed me to vary the frequency so that I could choose the best
frequency at which to run for a given application. Let me know if you're interested.

--- In Homebrew_PCBs@yahoogroups.com <mailto:Homebrew_PCBs%40yahoogroups.com> , Richard Spelling <rls@...> wrote:
>
> -----BEGIN PGP SIGNED MESSAGE-----
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> 
> Went to bed tired and annoyed I couldn't easily find a slower gear motor
> for the laminator.
> 
> Dreamed about building a magical speed controller that would let me run
> the existing motor infinitely slow.
> 
> Realized I could use "temporal kinetic and thermal stabilization" since
> it's a worm gear motor.
> 
> I.E., I build a standard PWM controller but set the frequency real
> sloowwwwww.
> 
> Imagine having the speed turned down real low. Along comes a pulse. The
> motor spins up and turns the worm screw a revolution or two, then spins
> down. The board advances a fraction of an inch. An in-determinant amount
> of time later, along comes another pulse.
> 
> Yes, it's "jogging" the board forward and not continuous motion, but
> between jogs it sits between the rollers long enough for the heat to
> transfer through the paper.
> 
> I'm thinking about 10Hz.
> 
> Whatcha think? Just another crazy idear from Richard?
> 
> Now I just need to build the board.
> 
> Wait a second, I need my laminator to build the board to fix the laminator!
> 
> 
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