When I was a kid I used to have a couple of racetracks that you hooked some batteries up to and you could make the cars go around the tracks by squeezing a handle.
Because you know in NASCAR they use handles that look like a squirt bottle to race or something like that.
This was the early 80’s and batteries were fairly expensive as I was told I was living far below the poverty line. Using a power supply from an Atari 2600and some wiring from a Radio Shack 200-in-one I rigged up an adapter and went from ~1.5 volts/500mA to the little engines to 9 volts ~500mA.
It worked, and as I recall it worked well. My eightish year old brain thought that was incredibly cool and that perhaps I would achieve even more speed if I could up the voltage a bit as my understanding of how a magnetically turning engine worked was the more volts the faster the turn.
I’d worked out from burning through several batteries that eventually the engines got hot, the cheap metals would expand due to use, and eventually the engine would seize and not be workable any longer. I needed to both up the voltage and reduce heat, which I assumed was from friction.
I told my mom what I was doing, who was pretty sure there was not much I could damage with batteries and my imagination. She was probably right as the sum total of all of our batteries probably could have burned me if I hooked them up in sequence but there was no particular worry that I would burn the house down.
Unfortunately I’d just learned from one of my 200-in-one projects, or perhaps one of the old science books laying about the house, that adding a 1.5 volt battery to another 1.5 volt battery did not = 3 volts, which is what I was assuming I needed to get the motor turning faster (it went faster on the 9 volt power, my little self was sure of it (honestly don’t recall now)).
I first worked out that to reduce friction in an engine one used oil. I saw this on TV. Oil lubricated engines. WD-40 was a water displacing oil. I would use WD-40. It also worked well as I could simply spray it into the engine.
I next chose an engine that if something happened to it I wouldn’t particularly mind. I wanted to do a test run at the higher voltage on just an engine before I worked on the track in case the cars went so fast they flew off the track and broke through the wall. That was how awsome this was going to be.
Next I grabbed my new power adapter. This one from a 1960’s lamp we had laying about. It was two wires and a plug.
Then as I wanted to make sure everything was neat I placed the engine on a piece of paper figuring the WD-40 might come out at high speeds and then I placed the plug into the only higher voltage thing I had access to.
The wall outlet.
Now, for those who have just glossed over this there’s a tiny electrical engine completely filled with WD-40 which is an absurdly flammable substance to begin with, and I just plugged an electric DV engine with a max rating of maybe .75 Watts into an AC wall socket capable of 3000+ Watts.
The explosion was unexpected. I couldn’t see for a couple of minutes. My mom was outside mowing or tending to a plant as I recall. She heard the fuse box in the garage shriek as a glass/wire fuse gave its life.
There had been a fireball of about the size of a basketball, the engine was larger… much larger than it had been when I plugged it in. The explosion had stretched the casing.
My guess is the paper that the engine had been on went up. I never found it or found evidence of it.
That was the last time I mucked with wall power until the great Capsella Experiment of 1984 and subsequently learning how to replace an outlet.