The disassembly of a cheap LED night light bought from a UK seller that appeared to specialise in pound-shop type stuff. It was available in red, yellow, green or blue which hinted at its use of a standard LED as a lightsource, although it does have the appearance of a typical electroluminescent night light (until lit).
The power supply is a text-book capacitive dropper, although the choice of some of the components is dubious, especially the 250V rated dropper capacitor and it's close to the bone 270K discharge resistor.
The switch on the side is fairly pointless, but may allude to a previous version with an optional light sensor mode.
My apologies for the random colour correction applied by the iPad I used to record this video. It doesn't appear to have any control over it's colour temperature settings to disable automatic white balance.
The power supply is a text-book capacitive dropper, although the choice of some of the components is dubious, especially the 250V rated dropper capacitor and it's close to the bone 270K discharge resistor.
The switch on the side is fairly pointless, but may allude to a previous version with an optional light sensor mode.
My apologies for the random colour correction applied by the iPad I used to record this video. It doesn't appear to have any control over it's colour temperature settings to disable automatic white balance.
i have the exact same one as that but with US plug
A 1 amp fuse will protect against Armageddon?
Pity nobody told Bruce Willis. 😁
Six years later, Big Clive still uses the same screwdriver. Must be good then. Have to buy one 🙂
Lol "…….. to make it more combustable".
Just happened onto this neat little video, very interesting to watch. A couple of years ago, I picked up a battery powered night light built somewhat the same, on LED but this one takes, I believe 3 AA cells and, of course is in a larger case. It has a sensor on it so only comes on in a dark room, but also has a motion sensor so it remains dark till there is movement in the room as well. I purchased it for the bathroom in our Class A motor home, as we enjoy boon-docking which is living in the wilds with no shore power or water hookups, in fact no neighbors or bothersome dogs, just the coyotes and raccoons that inhabit the wilds where we choose to travel. The night light works wonderfully, other then sometimes, when you sit and think a bit too long, she times out and you have to wave at her to wake her up when it is time to find the paper. Thanks a million for the great videos, I still maintain that if you learn something new, just one thing new each and every day, you will keep your mind active and not let her go to waste as many who sit glued to their televisions day and night when they are retired seem to do. Mom is now 93 and still going strong, a condition I attribute to her love of playing cards, she still makes the long trip down town to the Senior Center to play cards twice a week to the disappointment of the other seniors, as she is quite good and usually comes out the overall winner of the day.
Being from Canada and our main is 120 volts, doesn't mean I could when building just divide in two the components?
So wait, the resistor is dissipating 200 mW and the led is using 60? So a 1M bleeder resistor would save roughly 3/5ths of the power used by this light…
What was the purpose of the 3-position switch? It seemed to only do on or off. I wonder if there's a different model which has a light sensor mode.
I wish you would do a vid on the electro luminescent kind. I've seen them before and been curious. Just never taken one to bits.
So cheap, if I was to make it it'd probably cost about $5-10 Aus and that's going down to the the local Jaycar.
I have a US variant of is, however, it is dual color depending on the switch setting, either green or blueish.
ok, Clive. I am fascinated by these "voltage dropper" circuits. Back more than a few years ago, I was taught V=IR and voltage dividers were made with resistors. Is there some kind of formula for designing with voltage droppers? They must have some limitation as to current they supply? How does one know that the load on the circuit does not exceed what the circuit can safely offer.