DIY ATTEN 936B to T12 Soldering Iron

If you have an old ATTEN 936B soldering iron lying around, and its test power feels a bit low, and you mostly use T12 tips, then you can follow this guide to turn the ATTEN 936 shell into a mains-powered T12 soldering iron. If you're interested, why not check out this article?

Before you start, you need to disassemble the ATTEN 936B soldering iron, and then take a look at the original ATTEN transformer. The stock transformer is a bit small, but the voltage is very high—after rectifying, it reaches 37V—so you'll need to modify it a bit.

The original enamel wire is quite thin, and reducing the number of turns is a bit tricky. If you don't want to use the original wire, you can find a transformer from a speaker. Its voltage is 13.5V. If it's a bit low, just adjust it to add more turns.

Next, you need to peel off the insulation paper.

Then, find 1mm diameter enamel wire for soldering and start winding the coil.

If you notice a problem after winding a turn, like the silicon steel sheet being too sharp and easily damaging the enamel, you should quickly wrap a layer of high-temperature tape around it.

As shown in the picture below, a just-right length of enamel wire gives the perfect voltage—18V AC, and 25V after rectifying—which works perfectly for the T12.

Then you can continue to use the original ATTEN shell, like in the picture below.

This transformer is a bit bigger than the original, but it still fits.

In addition, you'll need to prepare a T12 main control board and assemble everything together.

Once assembled, you can start testing it.

You'll also need a large knob, like the one in the picture. If you have two types of handles, you can make two output tips, and swap the handle whenever you want.

Done.