There are a number of large components on the Circuit board near the
connection point to the fuser. Several, what I believe are solid
state relays - a triac w/heatsink (I think), some transformers etc.
The optocoupler I am not sure of. There are a number of opto-
switches (the slotted devices used to sense something between
them). I don't think this is what you are referring to though so I
will study the PCB some more to see if I Can find something that
looks like an Optoisolater chip.
On the fuser itself, there are the power wires going in one end of
the unit. On the opposite end, there are two groups of wires going
in - I am assuming one of those two sets of wires is the
thermostat. I didn't want to mess with it too much till I found out
what I should be keeping and such.
The unit seems to accept a PCB board without trouble and by turning
the shaft by hand, it will pass right through.
I do have a photo-type thermometer that I use all the time around
the shop - goes up to 400 degrees F so that should work good. I
will have to scrounge a motor somewhere. It is winter here now so
the retailers have all the grill stuff packed away - but, with
Christmas getting close, as soon as that is over, the summer stuff
will be back on the shelves again.
> 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
>