Wednesday, April 22, 2009

Low Melt Soldering on a Budget

From the pen of Nathaniel Erg:

After finally calling a halt to the multi-day festivities that were sparked by the blogs first birthday, I thought I had better finish the Greek Tragedy that was my initial attempts to use Low Melt Solder on a WM kit.

As previously mentioned, Cabbage Stokes (From up the Valley) stepped in to lend me his "HomeBrew" model, and at the same time pillaged an old PC I had sitting in the workshops of its power supply.....and within a week, this had arrived back:



Through electrical trickery (of which I have no knowledge), Mr Stokes was able to use the power supplies ability to switch between different voltages to power the 12v iron previously purchased, thus controlling the irons temperature. For this to happen, the iron leads are plugged into a combination of the 4 plugs presented on the top of the supply, labelled so:



This is the clever bit. By placing the black lead in the black "-ive" plug, I can then get the voltages of 2.2, 5.0 and 12v by simply moving the red "+ive" lead around. However, as shown on the pen marks, I can also get 7.0 and 8.7v by leaving the red lead in "12" and moving the black lead. How it all works is a mystery, but work it does, and exceedingly well. Experimentation has shown that for my own use (3/16ths, etc), 7.0v (as shown above) is the best setting.

I'm sure if enough interest is shown, I can convince Mr Stokes to come away from his Steam Powered Drawing Board where his latest Brass creation is undergoing gestation for long enough to draw a circuit diagram.

Postscript: That wasnt quite the end of the story; something wasnt quite right when it was first delivered, meaning I was making low melt bonds with it set to 12v. A quick visit to the builder fixed those shenanigans.

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