Homebrew PCBs

I concur with Jim. 
DJ was the first to let us know about the proper way to 
modify the laminator and the proper process.
I haven’t seen him posting here lately, but years back, he was very helpful in this
group.

Jean-Paul
N1JPL


> On Dec 16, 2016, at 11:46 PM, Jim Pruitt jpruitt67@gmail.com [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:
> 
> 
> I got my information from DJ Delorie's site:
> http://www.delorie.com/electronics/laminator/
> 
> I have seen other references but this one was the easiest to spot.
> 
> Good luck.
> Jim Pruitt
> 
> 
> On Fri, Dec 16, 2016 at 8:35 PM, 'K5ESS' k5ess.nothdurft@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com>wrote:
>  
> 
> I may have missed a posting RE toner melting points.  Can you point me to where the melting point of various toners can be found?
> 
> Thanks,
> 
> Mike N.
> 
>  
> 
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
> Sent: Friday, December 16, 2016 9:20 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] Re: GREEN TRF is the the same thing as Heat Transfer Foil Pigment La
> 
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> 
> ANY hacking of ANY electrical appliance can lead to plastic meltdowns or fire.
> That is the nature of hacking.
>  You don't even think of walking away from one of these before it cools off.
>  If you do then thats on you.
>  
> AND
> since I did succesfully raise the temperature without melting plastic structures
> I concluded it would be feasible if the nylon plastic gears were replaced with metal gears.
> I ruined ONE nylon gear running heaters at 390 degrees. 
> I would not have let the heater go above 350 if it had not been for the question of 
> COULD we use the 370 degree BROTHER toner ...not just 340 degree HP toner.
> 
> And as far as speed control goes.......
> I didn't sprinkle any spice on a 555 to make PWM.
> 
> I just told the MOC3020/BTA24 triac circuit hanging off a PIC16F628 pin to stop...wait a few seconds...then
> go. I figured I already had triac heater control so it was simple enough to control the motor.
> All parts ...soup to nuts cost about $12 for heater and motor control by one PIC16F628 with an LCD
> to keep track of settings.
> http://www.learnmorsecode.com/laminator/pic/index.html
> Noting the pictures show the hot press and not the laminator in use.
> 
> 
> On 12/16/2016 09:34 PM, mosaicmerc@... [Homebrew_PCBs] wrote:
> 
>   
> 
> The only doubt I have about that approach is that tampering with the heating mechanism to push temps above design specs. can lead to plastic meltdowns, and possibly a fire.
> 
> Slowing the rollers however is a different matter as it doesn't risk exceeding the device specs without added protections.
> 
> 
> Since you raised the point I gave it some thought and even did a small LTspice sim.
> 
> It would appear that rectifying the 120VAC into DC (like a PC SMPS or cellular phone charger)  and then producing a stepped replica of a sine wave using scaled PWM fed into a 220 uF or larger cap (as also found in PC SMPS units): we can have a variable frequency sinewave suitable for altering the speed of a  <200mA synchronous AC motor without risk of a breakdown or fire.
> 
> The caveat here is we're dealing with the 120VAC side of things and must design appropriately.
> 
> Now to drive the sine wave PWM...a 555 chip can do it via an optocoupler into t he high voltgae FET (also found in a PC SMPS) 
> 
> This is it in principle, but not exactly,as we'd need a variable freq sine wave source perhaps from 10Hz to 60hz.
> Generating PWM from rectified sine wave using 555
> 
> 
> Generating PWM from rectified sine wave using 555
> 
> I want to generate a PWM signal from a rectified sinus wave similar to the image below using 555 timer IC. I have designed the circuit below for this. I want to get...
> 
> View on electronics.stackexc...
> 
> Preview by Yahoo 
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