Yay, my corded cordless drill is cordless again!
If you don't recognize that, it's a Horrible Fright special, $20 cordless drill, originally with NiCd battery (long since deceased -- overheated and overcharged, because the charger is literally an AC adapter, diode and LED).
Well, instead of giving up on it, I soldered wires onto the battery terminals, and used it as a corded drill, within reach of my bench supply. (Amazingly, the chintzy speed controller -- a MOSFET, an SO-8, and a few chip resistors and "////" region on the PCB emulating a potentiometer -- is able to suck down quite a lot of current, enough to brown out my beefy supply!)
Somewhat more recently, I built a 12-24 to 18V converter box for it. This is based on my LED flashlight (written up elsewhere on here
), with extensive but fairly straightforward mods to adapt it to a much more powerful output stage (50V 40A peak switching, versus the original design's 10V 5A), in a Ćuk converter.
https://www.seventransistorlabs.com/Images/CukHack1.jpgAlso, it feels nice to finally spell Ćuk correctly here.
So, I happened to have a 12V gel cell handy, and needed a cordless use tonight. So, I put two and two together. That was tonight's story.
Tim