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2009-12-31 by Stefan Trethan
They do sell actual soldermask film which you can apply and photoprocess much like this. I don t know where you can get it, just wanted to make sure you know
2009-12-31 by DJ Delorie
... I ve noticed the riston will bubble up if I overheat it with the hot air gun (all the more reason to use a known-temp laminator control :) It doesn t seem
2009-12-31 by Ben L
... That is what I was thinking that the Heat would melt the resist, as I use positive resist boards and have left the Positive Resist on and soldered the
2009-12-31 by DJ Delorie
Some feedback about etch resist as solder mask... it s pretty but it melts at soldering temperature.
2009-12-31 by sailingto
That looks like a neat circuit. I have bookmarked it for later. Thanks for the info and help - I also just joined Electronics_101 group. Looks like a good
2009-12-30 by Stefan Trethan
Remember that PWM alone does not constitute closed loop control, it is open loop. You still need some way to measure the temperature and adjust the PWM to keep
2009-12-30 by DJ Delorie
... In my case, I also use the laminator for photofilm, and then the actual temperature is much more important - 240F for dry laminating and 205F for wet
2009-12-30 by Andrew Mathison
Dear RDHeiliger I had to comment because I personally feel you hit the button so to say with your commnts, particularly with the last sentence, where I feel
2009-12-30 by Stefan Trethan
There s no need to linearize, calibrate, etc., all that matters for a thermostat is that is keeps the same temperature (or close enough). I don t think it
2009-12-30 by RDHeiliger
When I looked into using thermistors for laminator temp control, I looked at the maximum temperature spec of the thermistor. Few of them can withstand 170 *C.
2009-12-30 by Stefan Trethan
If you need an output referenced to zero this would be a better circuit:
2009-12-30 by DJ Delorie
This is why I went with a single-chip solution that converted a thermocouple to a degrees C SPI digital output. No analog, no math, no guessing...
2009-12-30 by sailingto
Thanks for the info - since I m not sure about how to build an Opamp circuit, I found some thermosistors on digikey I think I can use. They are 1,000 ohms at
2009-12-29 by Trevor
Great stuff as usual. There is an instructables entry about a guy who did this as well. Might be of use to you or maybe even worth asking him some questions.
2009-12-29 by Stefan Trethan
No, amplify it with an opamp first. Some atmels come with up to x200 internal amplifier now, not sure if that would work. ST
2009-12-29 by DJ Delorie
First, some photos: http://www.delorie.com/pcb/lab/ I wanted to try this in case I needed it in the future, and this board was simple enough that it didn t
2009-12-29 by sailingto
Stefan, are you saying connecting a Type J (or K) Thermocouple direct to an analog input pin using a PIC12F683? What about a AVR chip such as a ATmega168 or
2009-12-27 by saposoft
Yessss Sir ! Just found one in a Laser Printer dismantled to make a laminator , was just wandering if it could be used for a noble scope like this one .... I m
2009-12-26 by Stefan Trethan
In this kind of application it is often acceptable to work without cold junction compensation. (Room temperature variations would be inside acceptable
2009-12-26 by rdheiliger
I have modified my PIC based temperature control to use a K thermocouple instead of a LM34. I used an AD595 chip to linearize K thermocouples to 10 mV/*C. This
2009-12-26 by Homebrew_PCBs@yahoogroups.com
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Homebrew_PCBs group. File :
2009-12-25 by Donald H Locker
Oh, good. I was hoping that would help. The tolerances on the final solution were rather loose, so I took my cue from there. And I m glad the example
2009-12-25 by Roger Blair
Thank You, Donald! The HCl concentration is 10%. I overlooked that part… I appreciate the breakdown (especially the reasoning, as it provides me some insight
2009-12-25 by Donald H Locker
Using 1.2 as the specific gravity of HCl (I didn t look it up, but that should be close enough for this approximation) Your recipe calls for 10g FeCl / (100g
2009-12-24 by Roger Blair
I found a formula for tin-copper alloys that I would like to try, consisting of: Distilled water or methanol, 100 ml; Hydrochloric acid, 5-25 ml and Ferric
2009-12-24 by sailingto
I guess I m old also (well, I am OLD!!) and suffer from CRS along with other infirmaries... I didn t read the next msg in line to see where you posted the
2009-12-24 by sailingto
I guess I m old also (well, I am OLD!!) and suffer from CRS along with other infirmaries... I didn t read the next msg in line to see where you posted the
2009-12-24 by sailingto
Well, share with the rest of us - do you have schematic? photos? I ve been looking for a cheap and easy to build temp controller. Ken
2009-12-24 by Stefan Trethan
I have a wonderful fan controller circuit! Here you go: Of course you do not need the voltage regualtor part if you have a
2009-12-24 by Stefan Trethan
I have lost the schematic. I tried to find it when the question came up a few days ago but can t find it! There was even a guy in Brazil(?) which duplicated it
2009-12-24 by Lez
... I need to keep a heatsink, its about 3 inches by 2 inches, in a switch mode psu, cool, about 35degC would be fine, I have a fan that easily manages the
2009-12-24 by saposoft
Well Well this is fantastic ... care to share the schematic ?
2009-12-24 by Stefan Trethan
I used a thermistor, and a BC547 transisor in place of the ua741. ICs are way too expensive to waste on a thermostat ;-) ST
2009-12-24 by saposoft
I forgot the most important part !! Where it is ! http://sites.google.com/site/elettronicaarduinoesperimenti/Home/thermostat-with-ua-741
2009-12-24 by saposoft
I m pretty sure to have seen something in this line previously in the group, but i can t remember when , so I decided to do it myself . Based on an idea taken
2009-12-22 by Roger Blair
One-time is just what I had in mind. Appreciate the flag. Regards, Roger From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf
2009-12-22 by Roger Blair
Hi Bryan, My interest here is in being able to make few-at-a-time spring contacts and such for proof of concept design work; definitely small quantity, hobby
2009-12-22 by Stefan Trethan
People might be reluctanct because of the tin in the bronze. I m not sure what it will do, but I d avoid putting anything other than copper in my etching tank.
2009-12-22 by m10000_little_zip
Any interest in testing this on the parts I am looking for? I ll provide material and artwork!! Thanks for your consideration, Bryan ... From: Roger Blair
2009-12-22 by Roger Blair
Duly noted. Thanks, ST Regards, Roger From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Stefan Trethan Sent: Monday,
2009-12-22 by Roger Blair
Thanks for the offer DJ, I appreciate that. I will just order a few phosphor bronze sheets and build a CuCl solution, and get with the program to see what it
2009-12-22 by Stefan Trethan
I d avoid the sulphuric etchants on suspicion, tin is used as resist there. Hardly anyone uses that in a homebrew setting anyway. CuCl eats anything short of
2009-12-21 by DJ Delorie
I suspect the process is the same, along with undercutting etc, although the chemistry might have to change. Brass works with PCB techniques because the brass
2009-12-21 by Roger Blair
ST & DJ, Thanks for the input. Of course I expect to get my hands dirty working out the finer details applicable to my equipment, I m just looking for a more
2009-12-21 by DJ Delorie
Yes, thicker brass takes a *lot* longer, you want to make sure your etchant is fresh and hot or it ll be in the solution for an hour or so. Undercut is going
2009-12-21 by leon Heller
... From: Roger Blair To: Sent: Monday, December 21, 2009 6:18 PM Subject: RE: [Homebrew_PCBs]
2009-12-21 by Stefan Trethan
No there are actually people here who etch brass, just 99.9% don t and can t say all that much about it. You ll have to wait and hope that someone speaks up, I
2009-12-21 by Roger Blair
Wow! Thanks for all the enlightening detail! Is this list only for experts to upstage each other with advanced expertise? Roger From:
2009-12-21 by Harvey White
... Yes, and speed of drill and sharpness of drill. Faster and sharper the better the hole. You might want to increase the size of the pad itself a bit. I
2009-12-21 by leon Heller
Leon Heller G1HSM ... From: blalor76 To: Sent: Monday, December 21, 2009 2:06 PM Subject: [Homebrew_PCBs]