A Simple Power Supply.
OK, I had this plug-in charger going spare. I'd bought it to replace a lost power-supply for a car DVD player, but it wasn't up to the job.
Time to give it a new lease of life.
Oh, It's *so* Hard to Make...
I lopped off the useless jacks, split the wire, stripped the end and soldered on the crocodile clips.
It was nearly as quick as it took to type this step.
It was nearly as quick as it took to type this step.
The Interesting Bit.
OK, so I have a cheap power supply (the charger cost me £2.99), so what?
Ah, because I can choose the voltage! It's a bit hard to see in the photo, but there's a sliding selector for anything from 0V (why??) to 12V, and a little recessed switch to swap the polarity as well.
One "problem", the voltage on the scale is wrong - a voltmeter across the crocs reads about 50% higher than the number on the scale. The working voltage is actually 4.5V - 17V.
It's not just a toy, it's been used in anger, to test the bread-board circuit for the version of Minty Beating Valentines Heart I'm part way through (https://www.instructables.com/id/EG7BX7AVJ7EXCFLX7K/ - I'm just looking for a suitable box to land a dragonfly on).
Ah, because I can choose the voltage! It's a bit hard to see in the photo, but there's a sliding selector for anything from 0V (why??) to 12V, and a little recessed switch to swap the polarity as well.
One "problem", the voltage on the scale is wrong - a voltmeter across the crocs reads about 50% higher than the number on the scale. The working voltage is actually 4.5V - 17V.
It's not just a toy, it's been used in anger, to test the bread-board circuit for the version of Minty Beating Valentines Heart I'm part way through (https://www.instructables.com/id/EG7BX7AVJ7EXCFLX7K/ - I'm just looking for a suitable box to land a dragonfly on).