Back in the mists of time, well August, I converted our old fibre optic Christmas tree from a heat-generating, electricity-guzzling halogen lightbulb to a cool, electron-sipping LED, primarily to stop The Snail of Happiness shop from becoming The Snail of Toastedness, but also to save the planet (and money on our electricity bills). In the ScrapHappy post, I mentioned that I would need to find a power supply to run it since the original one, like the UK’s recent prime ministers, was unsuited to the role**.
I decided that it was easiest to find an old unused mains supply and adapt it in some way. What I needed was something that produced about 5 volts, not particularly currenty (or curranty for that matter), that is, I didn’t need many milliamps, and could then just be adapted with a new bit on the end to plug into the tree (I was betting that I wouldn’t have a supply with the correct plug on it).
I found the perfect supply – 5 volts, a few hundred milliamps. It was an old charger for a mobile ‘phone that had long since been put on a shelf waiting for me to do something creative with it***. I tested it to make sure it did what it said on the tin, well, moulded plastic casing. Hmm… it did not! It produced an LED-sizzling 8.6 volts, meaning I felt pleased I had at least tested it before attaching it to the tree.
Annoyingly, it was the only supply I could find that was vaguely what I wanted, so I made the decision to use it and attach a thing called a voltage regulator that I would build out of bits that you have lying around (well, bits I have lying around). And guess what?
Back in August 2021, I posted about taking apart some old electronics boards which happen to have a rather useful chip on them that is a simple voltage regulator – you just add a few other components et voilà! Your supply is perfect for your LED tree. And so to work…
A scrappy voltage regulator
As you can see, it required four other electronicky bits. The casing I used was from the lights I converted to candles (see here for the gory details). Could I find the correct sized plug? Well, no, but then I came across one that had arrived in an order about five years ago that, at the time, had been surplus to requirements. See? Keeping stuff for years for no apparent reason DOES prove useful… sometimes.
At last, The Snail of Happiness shop now has a colour-changing, cool-running tree in its window!
HAPPY SOLSTICE EVERYONE!
* Well, a fibre optic fake pine tree anyway.
** Ooh, political satire.
*** Like that’s going to happen anytime soon.