Circuit board pre-heat workstations are very expensive, $350.00 - $2500.00.

The goal of this instructable is to demonstrate how to make a circuit board pre-heat workstation for around $50.00 with no special tools and the majority of materials from Home Depot and Harbor Freight Tools.

Special Warning - Note This project involves working with AC line voltage and high current.
If you have little experience working with household line current please get someone to help you with this project.

I will try to assist you with areas of caution, but you must be aware that AC current can be very dangerous.

By reading this Instructable you must be aware that I am not responsible for any injury or damage you may cause to yourself or your surroundings. (With the normal warnings out of the way, lets have some fun)

Step 1: Bill of Materials

Get your pad and pencil we are going shopping:

Some 1/4" and 1/2" plywood from Home Depot or Lowe's)
(Future upgrade, I want to build a metal case for the heat blower and circuit.)

1 $9.99 Heat Gun from Harbor Freight Tools

1 Three prong (grounded ac power cord)

1 1 1/2" copper elbow pipe fitting

1/4" square tubing - or whatever size you can get

4 machine screws, nuts and washers

Power cord wire hold down clamp - Electrical department

16 gage wire (assorted colors)

16 gage wire nut and wire terminal.

Special Warning! (You must use at least 16 gage wire for the high current side of the circuit)

Smaller gage wire for fan and low circuit side of the circuit

Roll of steel strap (electrical department, Home Depot)

1 3/4" or 2" hole saw

Electrical Components

Q4015LT Triac/Diac (Mouser, Digi-Key or similar)

Heat Sink (nut and bolt to fasten heat sink)
(I used Digi-Key part number HS107-HD)


.1 uF Capacitor (Ceramic at least 50V) (Mouser, Digi-Key, Radio Shack)

10K Resistor (at least 1/2 watt)

100K potentiometer (variable resistor) (at least 1/2 watt)

4 wire Terminal connector strip (Mouser, Digi-Key, Radio Shack)

5 wire Terminal strip (Mouser, Digi-Key, Radio Shack)

12V DC Fan 60 cm X 60 cm X 25 cm (Mouser, Digi-Key, Radio Shack)

Knob to fit potentiometer shaft (Mouser, Digi-Key, Radio Shack)
<p>Hello,</p><p>Realizing that you made this some years ago, may I ask what the durability of the copper elbow and other parts has been like considering the heat involved?</p><p>Anything that you would have done differently?</p><p>Thanks for a nice 'instructable'.</p>
Hi, One of the reasons I put the cooling fan in the case next to the components. By doing so, this should keep the heat from the heat gun away from the circuit and the major components. <br><br>If you are using a larger heat gun, you can always use two fans and monitor the temp inside of the case.<br><br>Thanks
<p>I have been looking at the wiring in your photos and also at the general schematic.</p><p>What I haven;t been able to discern yet is how did you step down the 110 to get 14V for the fan that you added.</p><p>You mentioned the bridge rectifier, but that wold just transform the AC into DC. </p><p>Is there something that I have overlooked?</p>
<p>Hi pcarew, honestly, it has been so long I cannot remember.</p><p>But I did add two extra resistors to control the cooling fan, which later I removed one to keep the cooling speed up at lower speeds I believe that extra resistor lowered the voltage before going to the DC motor. Simple ohms law would allow you to figure that out. Sorry it has been way too long. If you are going to build the circuit, build the DC motor circuit on a breadboard first and double check the voltage. When I first checked out the heat gun, I measured the voltage on the back side of the bridge circuit and then calculated from there.</p><p>Thanks</p><p>Joe</p>
Hello Damion, <br> <br>I recall that when I built the circuit I removed the inline resistor as it was taking way too many turns to ramp. Your load may be different then my heat gun. I would try a larger value pot or add a higher resistor in serial to the existing pot. That may slow down the ramp. <br> <br>Thanks <br> <br>Joe
I'm having troubles with this circuit. As soon as I turn it on and adjust the pot in a very small increment it ramps to full power and the pot no longer controls it. its not even past a 1/4 turn. its like control circuit isn't there. I'm not a novice at following schematics it's wired right. I use the lower setting at 6.6A. Any ideas?
nice info
Can you upload schematic for regulator, web page is not accesible...please
Sorry zmatija,<br><br>I posted the link to the schematic years ago, It is no longer available and I no longer have the schematic. I would do some searching out on the web for circuits that are similar. <br><br>Thanks<br><br>Joe
You have to love the<strong> Internet Archive</strong> (A.K.A. the <strong>Wayback machine</strong>) Here is a link to the website that had the schematics. I have also attached the schematics themselves for future reference.<br> <br> <a href="http://web.archive.org/web/20070105221458/http://home.cogeco.ca/~rpaisley4/x1200WControl.html" rel="nofollow">http://web.archive.org/web/20070105221458/http://home.cogeco.ca/~rpaisley4/x1200WControl.html</a><br> <br> <br>
Very Cool tamagotono, Thanks for following up.<br><br>Joe
Very nice
I can't seem to find a (cheap) source of 5/2" copper elbows. Could I use something else (or bend something else)?
I just bought a digital heat gun ,& I would use it b/c I can set the temp exactly. but you should have put a temp gauge to show the temp. the controller you made is basic a light dimmer couldn't you just buy one they are rated for a max of 660 watts ? well we all use what is more convent in our own situation !
Very good instructable Nice pics Good explaning I'm rating u 5
Thank you. This is a very well done instructable.
Thanks Joe
hahaHAHAHA! I just bought one of those heat guns from HFT. The first one broke the first time I used it, make sure you save your receipt. Not bad for $10.
Yes, The first one I purchased died as well. But the second one has been going strong. I always purchase the 1 year warranty on HFT items. Thanks Joe
I found one of these at OSH
The title of this instructable makes it sound like a Doctoral Disertation. Not that it's a bad thing. It just reminds me of sitting at my bachelor's graduation reading the names of the disertations of the doctoral folks.
Awesome!! Extremely well done instructable, great pix. Thanks for sharing this idea and construction.
Thanks HamO, I like the mouse with the glasses and calipers. Joe Pitz

About This Instructable




Bio: Software Developer, like to work with electronics, embedded systems, robots etc.
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