Homebrew PCBs

Hi,

Finally I upload a photo ("Esteban" Folder in photos section)of my 
pcb with toner transfer method. 

Thanks to the Stefan Trethan aid, I build a thermostat circuit for my 
HP 4L laser printer fuser.

I am using only free catalog magazine paper.

One more time; thanks Stefan for your help.

Greeting from Chile
(sorry by my english).

Esteban Arias
earias@...

On Wed, 14 Jul 2004 00:47:14 -0000, Esteban <earias@...> wrote:

> Hi,
>
> Finally I upload a photo ("Esteban" Folder in photos section)of my
> pcb with toner transfer method.
>
> Thanks to the Stefan Trethan aid, I build a thermostat circuit for my
> HP 4L laser printer fuser.
>
> I am using only free catalog magazine paper.
>
> One more time; thanks Stefan for your help.
>
> Greeting from Chile
> (sorry by my english).
>
> Esteban Arias
> earias@...

nice board, clean work.
You might also want to try out component legend with toner transfer,
it is easy to do and really rewarding.

I'm glad i could help, and I'm glad you took the little help, added a good
amount of effort and work, and got a very good result.

I think i will set up a page publishing that temperature controller 
circuit.
It would be better to add integrating and rate components to make a PID 
controller
but i think it is hard to adjust for beginners. The simple circuit 
oscillates slightly
but the temperature does stay within my measuring resolution.
Maybe i'll add very low hysteresis to keep it from "free" oscillating.
As it is syncronous to the mains frequency it isn't really a problem.

Esteban, i would very appreciate discussing the performance of the 
thermostat on your
fuser. I think you have a ceramic heater and can't see when it's on? 
perhaps
you could connect a test lamp or something parallel to the heater.
What i'm curious about is if it is oscillating slowly or not.
We can discuss this off list i think.


ST

Stefan,

In the thermostat circuit, I placed a LED in serie with the LED of 
optocupler that drive the gate in the triac. I first power on the 
thermostat circuit and the LED is ON all the time, then, I power on the 
fuser with 220v and the LED begin to off and on slowly. Then, when the 
temperature in the fuser is 160 degree app, the LED turn off and on more 
fast and then maintain the frequency of oscillating. I think that frequency 
is 2 cicles for second.

I placed the temperature sensor of my multimeter in the teflon surface of 
fuser and adjust the temperature to 160º with the variable resistor in the 
circuit.

The main problem with the unit is the number of pass for the pcb. I roll 
slowly the fuser with a bipolar stepper motor but I need to pass 20 times 
the pcb for obtain the result in the photo. With this pcb, I tested to pass 
only 10 times the pcb, but not work, I ever need 20 o more. Maybe the paper 
type?, maybe the roll velocity of the fuser? or the temperature?

Esteban Arias
earias@...


At 12:43 a.m. 14-07-2004, you wrote:

>On Wed, 14 Jul 2004 00:47:14 -0000, Esteban <earias@vertice.cl> wrote:
>
> > Hi,
> >
> > Finally I upload a photo ("Esteban" Folder in photos section)of my
> > pcb with toner transfer method.
> >
> > Thanks to the Stefan Trethan aid, I build a thermostat circuit for my
> > HP 4L laser printer fuser.
> >
> > I am using only free catalog magazine paper.
> >
> > One more time; thanks Stefan for your help.
> >
> > Greeting from Chile
> > (sorry by my english).
> >
> > Esteban Arias
> > earias@...
>
>nice board, clean work.
>You might also want to try out component legend with toner transfer,
>it is easy to do and really rewarding.
>
>I'm glad i could help, and I'm glad you took the little help, added a good
>amount of effort and work, and got a very good result.
>
>I think i will set up a page publishing that temperature controller
>circuit.
>It would be better to add integrating and rate components to make a PID
>controller
>but i think it is hard to adjust for beginners. The simple circuit
>oscillates slightly
>but the temperature does stay within my measuring resolution.
>Maybe i'll add very low hysteresis to keep it from "free" oscillating.
>As it is syncronous to the mains frequency it isn't really a problem.
>
>Esteban, i would very appreciate discussing the performance of the
>thermostat on your
>fuser. I think you have a ceramic heater and can't see when it's on?
>perhaps
>you could connect a test lamp or something parallel to the heater.
>What i'm curious about is if it is oscillating slowly or not.
>We can discuss this off list i think.
>
>
>ST

--- In Homebrew_PCBs@yahoogroups.com, "Esteban" <earias@v...> wrote:
> Hi,
> 
> Finally I upload a photo ("Esteban" Folder in photos section)of my 
> pcb with toner transfer method. 
> 
> Thanks to the Stefan Trethan aid, I build a thermostat circuit for 
my 
> HP 4L laser printer fuser.
> 
> I am using only free catalog magazine paper.
> 
> One more time; thanks Stefan for your help.
> 
> Greeting from Chile
> (sorry by my english).
> 
> Esteban Arias
> earias@v...

Hi Esteban,

I'm impressed !  You did a great job.

I really like all the text in copper.  Also, the traces look like you 
were able to get good resist.

If you guys want to keep the discussion about how to set the circuit, 
I think most of us on here would like to 'listen in' and think that 
we would be interested in tuning the circuit.

Dave

On Wed, 14 Jul 2004 10:31:05 -0400, Esteban Arias <earias@...> 
wrote:

> Stefan,
>
> In the thermostat circuit, I placed a LED in serie with the LED of
> optocupler that drive the gate in the triac. I first power on the
> thermostat circuit and the LED is ON all the time, then, I power on the
> fuser with 220v and the LED begin to off and on slowly. Then, when the
> temperature in the fuser is 160 degree app, the LED turn off and on more
> fast and then maintain the frequency of oscillating. I think that 
> frequency
> is 2 cicles for second.

That is interesting. Your fast fuser seems to make this. With my big fuser
it is oscillations with about 1 cycle every 5 seconds or so.

Considering the controller is "syncronised" to the mains frequency (it can 
only
turn on/off complete halfcycles) 2Hz oscillation is very OK. you will not 
have any
variation in temperature there.

>
> I placed the temperature sensor of my multimeter in the teflon surface of
> fuser and adjust the temperature to 160\ufffd with the variable resistor in 
> the
> circuit.

I do the same. use a small amount of thermal compound on your temp. sensor
or you must wait long until it is heated up. also it is more accurate with
thermal compound. (But the small error doesn't count in this application)

>
> The main problem with the unit is the number of pass for the pcb. I roll
> slowly the fuser with a bipolar stepper motor but I need to pass 20 times
> the pcb for obtain the result in the photo. With this pcb, I tested to 
> pass
> only 10 times the pcb, but not work, I ever need 20 o more. Maybe the 
> paper
> type?, maybe the roll velocity of the fuser? or the temperature?


Tell me which PCB material you use (1 or 2 sides, thickness).
How thick is your paper? (estimate by comparision to known office paper).

How fast is it moving?
I will clock mine later and tell you how slow it is, it needs 1 pass for 
perfect results,
two or three if you want to make broad traces (pinholes).
I believe 1 very, very slow pass is more eficient, because the board 
doesn't cool
between passes.
Maybe you also should use 180 degree, i'll measure mine again in about a 
hour and tell you.
I think it depends on the toner make too.

I assume you pass it with the paper facing the heated roller, not the 
rubber one.


ST

P.S.: You really want to try component legend next time, i'll write up a 
howto soon.

..
>
> Hi Esteban,
>
> I'm impressed !  You did a great job.
>
> I really like all the text in copper.  Also, the traces look like you
> were able to get good resist.

Looks very clean, yes. Text in copper: i reduced it to almost zero after
getting the two-side component legend "silkscreen" done. you can put much 
more
information on it.

>
> If you guys want to keep the discussion about how to set the circuit,
> I think most of us on here would like to 'listen in' and think that
> we would be interested in tuning the circuit.
>

Getting his 2 second oscillation results i think there is not much 
tweaking needed.
Hysteresis won't make it better, and a rate component is IMO not helpful 
for beginners.
also it must be a very big rate comp. (heating systems are very slow) and 
i have
no experience with that, and no time to experiment just now.
The zero crossing detector of the opto "slots" the control input and 
prevents too much
oscillations i think.
If a control loop guru is willing to provide assistance i will try 
modifications.

ST

> Dave