Whilst going through some of my dad’s old things i recently found a beautiful little Microlite desk lamp made in the 1960s that reminded me of the little “Pixar lamp” from the movies. Unfortunately its transformer had gone on fire in some bygone year and since then the little guy has been unloved and gathering dust – since at least 1986.
There is somehow such personality in this little lamp that i had to find a way to bring it back to life. Firstly i thought, OK how about I get a new 12 volt bulb and make it battery powered with rechargeable batteries… So, I got the bulb from Halfords, but then soon realised that to get 12 volts I would have to cram rather a lot of 1.2 volt cells into the small body of the light, other cells like a regular 6 volt being too big. The lamp wasn’t really made for being opened regularly either. So i dumped that idea.
Soon after my mind rejoined the 21st century and so I thought, USB power and super efficient LEDs… OK!!! Time to visit my local electronics store to get some parts and advice! The components expert had loads of ideas, the best of which was to tell me about Adafruit products, one of which is this USB charging board with which you could build a custom portable phone charger or anything that needs a small amount of power at c. 1 Amp or less at USB voltage of 5V. It’s a clever little board with LEDs to indicate what it’s doing and ports for USB power in, power out and battery in/recharge.
So with the help of a multimeter and my new soldering iron, I created a simple series circuit that takes power from the board (which itself is either powered from USB in, or rechargeable Li-ion battery) and passes it through a 3W warm white ultrabright LED mounted in place of the old bulb. Added into the circuit is a potentiometer which acts as a smooth dimmer switch.
The circuit itself was pre GCSE level to plan and assemble. The Adafruit board of course is more complex internally but is super easy to work with and strongly built too.
What was more tricky was mounting everything securely inside the body where previously there was little more than a pleasingly heavy transformer!
That done, I now have a USB rechargeable desk or bedtime reading light, with dimmer switch for the small hours plus subtle coloured LEDs for the indication of power and battery status.
Beyond just a hobby project, I’ve brought something that my dad used to use back to life….. And that means far more to me than a few hours of being an electronics nerd.
Thanks Dad….. 🙂