Teardown of a simple LED night light.

[@JerryEricsson]

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.

[@AudinMalmin]

I have a US variant of is, however, it is dual color depending on the switch setting, either green or blueish.

[@SharkoonBln]

Six years later, Big Clive still uses the same screwdriver. Must be good then. Have to buy one :)

[@Mark1024MAK]

You do know that he has more than one of those....

[@Zyxxi]

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.

[@TheChipmunk2008]

Makes me wonder if they didn't screw up and use the 120v circuit in the case of the 240v one? (250v cap would be fine for 120v AC, and the resistor would be much more comfortable)

[@richbooth2427]

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.

[@bigclivedotcom]

+Rich Booth Yes. It's the formula for capacitive reactance. XC=1divided by 2 pi F C You'll occasionally see me crack out the calculator in some of the lamp videos. It basically gives you an equivalent resistance value for the capacitor based on its value and the mains frequency. The difference is that the capacitor does not get hot like a resistor would. It actually rations little packets of power through on each half cycle.

[@richbooth2427]

+bigclivedotcom Hmmmm... I do seem to recall that now that you mention it. If I was looking for 20mA here in the US, where we are 120v and 60Hz using V=ir yields 6K ohm. driving for C in the Xc formula yields 4.42nF

[@bigclivedotcom]

+Rich Booth That's way too low. I think the round value 470nF is closer to your result. Most capacitors used in LED lamps vary between 100nF to 2200nF. It doesn't help that the average calculator doesn't really deal with a nano Farad too well. 0.000000001

[@richbooth2427]

+bigclivedotcom Let's not forget that most old eyes have trouble reading most calculators. ;-) Thanks for replying (and single handedly keeping Poundland in business).

[@goose300183]

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.

[@stevecoatesdotnet]

Blue is a weird colour for a night light. Was that an actual BS1362 fuse it had? Hard to see in the video, but I thought it looked like a glass fuse.

[@bigclivedotcom]

It was a cheap glass fuse probably rated to break 35A at the most, so I should think its main safety action will be to blow the entire night light out the socket. Blue is supposedly not a good colour to use as a night light. The theory is that using things like phones and tablets in bed disrupts your sleep pattern because of the colour of the light from the screen. Obviously it's nothing to do with staying up until 4am watching KZbin videos.

[@regpollock9403]

Being from Canada and our main is 120 volts, doesn't mean I could when building just divide in two the components?

[@bigclivedotcom]

It would light OK on 120V. But with capacitive dropper circuits the different versions for 230V and 120V supplies usually just have a different rating of dropper capacitor.

[@regpollock9403]

Thank you.

[@BedsitBob]

A 1 amp fuse will protect against Armageddon? Pity nobody told Bruce Willis. 😁

[@JasperJanssen]

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...

[@PeterEdin]

Lol "........ to make it more combustable".

[@ajentsong6151]

i have the exact same one as that but with US plug

[@jpian0923]

3:13 LOL

[@WM2869]

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.