Hayling Island

Hayling Island

Friday, December 6, 2013

I love the smell of solder in the mornings ..

it reminds me of victory. A small success .. the (was a Weller) solder station using an arduino core (though just the processor and software, no ancillary junk) and some old TIL311 LED displays, a switch-mode power supply based around an L4960 and some donor parts from the Weller (enclosure, transformer, control, power switch, soldering pencil cable and a fuse) is now driving a hacked Hakko soldering pencil.

The PID code for the Arduino leaves a little to the reader to work out - like how to control the proportional, integral and differential parameters - but out of the box, as it were, it does stabilise and the soldering pencil melts solder (gasp). Temperature overshoots slightly, so need to wind up the integral element, I think.

My real frustration through the last couple of hours has been the number of times I have tried to solder something on the circuit board using the new soldering pencil, which wasn't working at the time. I have to say, these Hakko pencils are really nice to hold, and they fit like a glove into the Weller soldering stand (sponges for which cost more than the Hakko soldering pencil delivered to the UK from China).

When it's all bolted together again, I am going to post some more pics, the final schematic and a bit of Arduino code. Be gentle.

Did a front panel .. amazing how you can spend longer doing a front panel than designing the electronics. I have some Polaroid sticker paper, which you can put through an inkjet printer. I bought an HP  Photosmart 8700 printer from someone who had just found out how much cartridges were for it. It does an outstanding job, and these stickers make for very nice, small front panel artwork.

.. Corollary:

Managed to short the triac screwing the case together. I had to wait for a replacement, and found a chap on that auction site again selling them in New York. Only 10 days to deliver, but of course the fun with work, and with the Synth project, and fixing the car meant that replacing it went on the back burner.

But this morning, had an uninterrupted hour or so, and here it is. I resisted the temptation to scale the artwork so the soldering pencil went right up blondie's back passage. She got an ESD Safe virtual sticker there instead.

Wednesday, December 4, 2013

Hacking a Hakko

After the small issue with the Weller pencil, and not being able to afford to replace it, I ordered a Hakko clone from eBay. It took less than a week to get here from China - £6.99 including delivery. It is utterly stupid pricing .. compared to £95 for a new Weller handle.

And, you know what? The quality is really good ... I am going to borrow the line cord from the Weller to put on it, to save having to rewire a Hakko-compatible connector onto the base. So, have taken it apart, and I am very impressed. I'm so confident I am going to 1) buy another one and 2) buy some bits. That is the other small difference .. Weller ETC bits are £6 each, and Hakko bits are ... um .. let's see ... pack of ten for £4.39.

Of course I will have to re-calibrate, since Hakko use a PTC with some strange characteristic. I took this (room temperature, it's meant to be) partly to show off the TIL311 LED displays. HP don't make them any more - or at least I don't think so. These came from a project at work in about 1980; they've been sat in a parts drawer since then. I use them on odd projects that come and go .. always put them in a socket so they can get re-used. They are partly why I had to put a switch-mode PSU in the Weller controller - poor little 7805 nearly caught fire.