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Knowledge You Can Build On — Est. 1998

Building Woodburner Controllers - Again.....

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Building Woodburner Controllers - Again.....

#1

Building Woodburner Controllers - Again.....

Rob W.

>I recently asked about building woodburning controllers from scratch and got some great ideas about using the high current, low voltage (+5 VDC) supply from a computer power supply as the main guts of the controller.....however, converting one of these for woodburning use may be a bit challenging for some people...

Does anyone know if there are simpler circuits for a woodburning controller out there that do not require using a computer power supply?? (I'm pretty sure what's in the commercial woodburner units do not involve rectifying to DC, electronic voltage regulation, etc. but more likely consist of a step-down transformer and a rheostat or variac....) with a much less complicated wiring schematic...

I've had several private requests via e-mail to forward anything I learn on this topic, since some folks thought working with a computer power supply and other circuitry was too complicated for them.... Some comments received in the earlier message seem to bear that out!!

Thanks again for your feedback and advice!!

Rob Wallace

Re: Building Woodburner Controllers - Again.....

#2

Re: Building Woodburner Controllers - Again.....

Russ Fairfield

>A couple of the oldtime methods for controlling the heat to a burning tip. These may be crude, but they will work.

An automotive or small engine battery makes a good power supply if you can tap into the battery between cells. Hook up an automotive battery charger to keep it chatged.

You can also use the automotive battery charger itself as the power supply if it has an adjustable output. If you want more adjustment, put a piece of thin music wire in one leg as a resistor and adjust its length with an alligator clip as required to adjust the temperatre of the tip.

Re: Building Woodburner Controllers - Again.....

#3

Re: Building Woodburner Controllers - Again..... *LINK*

Fred in NC

>Not adjustable, but it supplies 50 watts right off the shelf! This is about right for a lot of woodburning uses. $9.50. Look in the link below.

AMPS * VOLTAGE = WATTS.

A PMW control in KIT form from the same source. It has all the parts, which beats hunting all over for them, $22.95. AT 12 V gives about 75 watts, and the output (heat) can be adjusted from about 5 watts to full power.

http://www.allelectronics.com/cgi-bin/category.cgi?category=305&item=MK-804&type=store


Power supply - 50 watts

Re: Building Woodburner Controllers - Again.....

#4

Dick Hines

Re: Building Woodburner Controllers - Again.....

Dick Hines

>Russ, it sounds like you are making a bomb. A couple gallons of gas and a way you go.

Re: Building Woodburner Controllers - Again.....

#5

Careful, the wire will get hot!

Fred in NC

>

Re: Building Woodburner Controllers - Again.....

#6

Re: Building Woodburner Controllers - Again.....

Russ Fairfield

>I prefer using the battery to the commercial controllers. There is less inertia in the battery; and that equates to a faster response time and a more constant tip temperature.

Re: Building Woodburner Controllers - Again.....

#7

Re: Building Woodburner Controllers - Again.....

Pascal Oudet

>Rob, when I did the same investigations as you some months ago, the common description I found was a dimmer, connected to the primary side of a transformer. the transformer must have a low voltage output, high current capabilities. simple dimmers are supposed not to work well with inductive loads (a transformer is one), but apparently they work. I haven't tried that, so can't really comment on this circuit.

you can also do a search in RCW archives, where I found most informations.

you can remove the PWM from my circuit and use the 3.3V output directly, but I fear the power to the tip will be too high.

another idea: one friend took an old electric heater, and used it as a resistor to decrease the power to the tip (connected to the SECONDARY side, in series with the tip).

hth,

Pascal