Homebrew PCBs

On Fri, 02 Dec 2005 14:47:10 +0100, lcdpublishing  
<lcdpublishing@...> wrote:

> Hi Stefan,
>
>
> My buddy gave me an old (about 3 years) laser printer.  He believe the
>
> fuser is good so I might have a fuser to hack!  I will start pulling
>
> the printer apart tonight if I don't get called out of town again.  I
>
> recall you mentioning certain critical parts I need to keep from the
>
> rest of the printer so I won't butcher it up too bad.  Can you refresh
>
> my memory as to what else I need from the printer?
>
>
> Also, what sort of motor did you use to drive your fuser?  I remember
>
> you saying it takes about 1 minute to pass a board through, so I am
>
> guessing you are using some sort of gear motor.
>
>
> Thanks!
>
>
> Chris


There must be a triac in there and a optocoupler, which are useful. But  
you could also use any solid state relais to make the thermostat. If you  
follow the power wires of the fuser (the ones that go to the lamp inside  
the roller) those will lead you to the interesting PCB. Also keep the  
thermistor with the fuser (two thin wires coming out of it). You just need  
to keep the thermistor with the wires, the electronics using it are  
usually no good.

For a motor i use a chicken grill motor. Mine is a belt-drive with about 2  
to 1 ratio, but direct drive would be OK, especially with the smaller  
diameter rollers of a fuser.

I have the schematic for the simple thermostat somewhere, i'll dig it  
out...

You'll want some type of thermometer that can measure the temperature of  
the hot fuser roller to set it up, i suggest a thermocouple sensor on a  
multimeter with temp. range or maybe a optical thermometer (although i  
dunno how well they work on the fuser surface).
You can use browning of paper and stuff, but it's really better to know  
for sure.

ST