Homebrew PCBs

Yes Stefan, I have the main board of the HP printer. Close to triac this 
have a optocoupler. I searched in the net and found the datasheet of the 
triac and of the optocupler. The pcb is only of one face, then I think is 
easy tracking the conecction between components.

This week I go to vacations of summer, but to my return I will to tracking 
the circuit, make a schematic, write the components values and send this 
information for to obtain its help.

Thanks for your time.

Esteban Arias
earias@...



At 05:19 a.m. 11-02-2004, you wrote:
>On Tue, 10 Feb 2004 21:19:48 -0600, Esteban Arias <earias@...>
>wrote:
>
> > Thanks Stefan for the schematic. Now I have a good idea over the circuit.
> >
> > Today I search in my house and find the main board of the printer. I
> > review
> > the pcb and find the components asocciates to the fuser; BCR8PM a 8A,
> > 600V
> > triac. I think use the same triac for driver the fuser but with your
> > circuit.
> >
> > The service manual say over the internal thermistor: "TH901". I think it
> > is
> > a 10 K thermistor. it is ok for your circuit ?
> >
> > Thanks,
> >
> > Esteban Arias
> > earias@...
> >
>
>hi,
>
>10k thermistor is well posible.
>
>you want to use a triac, this needs to be triggered.
>
>
>it will work with my circuit but would need 1 more component.
>
>You can't connect the triac to my circuit without isolation.
>The temperature sensor in the fuser is not isolated for 220V you may
>damage the sensor and endanger yourself.
>
>The common procedure would be to use a optocoupler.
>
>(this is the same as in my solid state relais. it is just
>a optocoupler and a triac.)
>
>There are Triac optocouplers (consisting of a light-sensitive triac and a
>diode).
>these are nice for such applications. (but any other optosiolator will do).
>
>Tell me what you have at hand, i think the HP printer triggers the triac
>with a opto
>too so this will not be a problem.
>
>If you need help with a circuit tell me which parts you have.
>
>The printer has powered the fuser - so it must contain all components you
>need
>(spare the potentiometer). No need to go shopping i think.
>
>
>
>ST