Homebrew PCBs

On Tue, 10 Feb 2004 17:03:33 -0300, Esteban Arias <earias@...> 
wrote:

> Hi Larry,
>
> I am working in the same. I have a fuser of a HP 4L. Do you have
> information over the exactly frequency of operation for this fuser??
>
> When the paper (or the pcb) is running inside the fuser, then the fuser 
> is
> all the time On or ever the fuser is on and off ?
>
> Thanks, and sorry by my english.
>
> Esteban Arias
> earias@...
>


no, i wouldn't power it full time when the pcb is in.
make a good thermostat and it will be full on time if needed, but it will 
not overheat.
(which it will if you let it really on full time when the pcb is in.

I think the HP holds the fuser at a "standby temperature" and then quickly 
heats it up when
the paper comes through.

there is a temperature sensor in most fusers, use it, it is working fine 
for me.

i made a simple thermostat with a relais and a potentiometer, nothing else 
needed.
i used a solid state relais (because i added no hysteresis, a contact 
relais would burn out then).

it works perfect, i can't measure any variation or swing with my 
multimeter (0.5 degree i think resolution).

ST