Time sure flies. I haven’t posted here in a while, but I thought I’d upload a few pictures of the most recent hack around the bench. Took my old Radio ‘Battery Eliminator’ (12V, 3A), and converted it into a constant voltage/constant current supply using a little module I got from China (link here)
Moved the transformer inside the power supply back to make a little more room, and added a supply line fuse (it had an output fuse already). Once that was done, I hacked the front to make the new module fit and added a couple of binding posts, making sure of the 0.75″ spacing (unlike the last time I hacked something like this), and I think it turned out rather well. I may still add an internal fan if it gets too warm, but I don’t use enough current out of it for that to likely be a problem.
I had also heard that these things weren’t particularly accurate, so I was curious to see how close it really was. I hooked up an LED bulb (supposedly 2W, but closer to 1), and the current showed 94mA and the meter (Yes, the BM235 from EEVBlog) shows 96.1mA so about 2.5% off, but that’s close enough for the stuff I do. It will be nice to be able to limit current, and also to have a quick current display to glance over at, rather than having to hook up a meter when I want to read it.
Of course the picture also shows my 1970s vintage Weller W-TCP-L, which is still going strong 40 years on. I’ve bought new tips (mostly use a 700 small chisel – for PCB work, and an 800F larger chisel – for bigger work), and it’s a champ.
Now to get back to what I came downstairs to do, pack up a Tindie order. THANKS GUYS for all the support. I’m not getting rich selling on Tindie, but it’s still a thrill to get an email saying “you have a new order!”