Philips 120V LED lamp on 220V? - Page 1
Forum section: electronics / general

author: Kaptein QK
author_rank: Regular Contributor
timestamp: April 17, 2013, 01:41:38 pm
content: I bought a Philips 17W LED lamp off Ebay, see picture here:http://www.flickr.com/photos/90579103@N08/8658152918/#It says 120V on it, but I live in Norway and we use 220V.Many other LED lamps with a proper power supply has a wide input range which covers 110 and 220V, so I assumed this one had as well.Does anybody know? I tried Google but found no answers.Should I just take cover and plug it in?Or take it apart and check the voltage rating of the input cap, controller and the other components?

author: Balaur
author_rank: Unknown
timestamp: April 17, 2013, 02:02:09 pm
content: I'm very cautious about any stuff that goes into mains for both technical and liability reasons.If it doesn't says 220V on it, then I would stop here. It may be very possible for Philips to design the bulb circuitry to be universal, but are the capacitors on this particular version rated up to the 240V?I had a proper 220V Philips CFL that broke on me because of a capacitor that I've been able to replace it. It makes you wonder if a 120V bulb in a 220V network will be much more successful.Best regards,Dan

author: PA0PBZ
author_rank: Super Contributor
timestamp: April 17, 2013, 02:02:54 pm
content: The picture you linked to clearly says '120V' on the lamp, my guess is if it had been designed to work on 120-240 it would have said so.Taking it apart is not an easy task because the power supply will be potted.

author: Joules
author_rank: Contributor
timestamp: April 17, 2013, 02:54:35 pm
content: Buy a second one and put it in series O0

author: Kaptein QK
author_rank: Regular Contributor
timestamp: April 17, 2013, 04:11:34 pm
content: Quote from: Joules on April 17, 2013, 02:54:35 pmHaha, good answer!However, I could not resist my urges and I dismantled the lamp.I unfortunately got a bit of "Potting Rage" (Closely related to the "Wrap Rage"), and broke a part of the board.Pictures:http://www.flickr.com/photos/90579103@N08/8657405103/#http://www.flickr.com/photos/90579103@N08/8658514800/#http://www.flickr.com/photos/90579103@N08/8657410359/#http://www.flickr.com/photos/90579103@N08/8657412719/#The main cap is 250V so it would have been a bad idea to plug the lamp in to 220V.I will buy a 220V power supply and put it into it.

author: eevblogfan
author_rank: Frequent Contributor
timestamp: April 17, 2013, 04:32:46 pm
content: since I'ts using DC . put 2 220V caps in series and put them accross the mains ( after dirode bridge of corse ) and then tap only one of the cap's contacts . you should get 120 , and please put some 1M or even 400K bleeding resistors ! accross every cap !I think ATX uses that method

author: PA0PBZ
author_rank: Super Contributor
timestamp: April 17, 2013, 04:48:31 pm
content: Quote from: eevblogfan on April 17, 2013, 04:32:46 pmUsing caps as a DC voltage divider? Not sure what you smoked but I'd like to have some too

author: eevblogfan
author_rank: Frequent Contributor
timestamp: April 17, 2013, 06:19:57 pm
content: PA0PBZDon't laugh at me I was serious , I've seen that implemented with ATX'sobviusly it was pulsed DC I pressume

author: PA0PBZ
author_rank: Super Contributor
timestamp: April 17, 2013, 06:24:57 pm
content: I think you are confused by the fact that some of these power supplies are switchable between 110 and 220, for 110 the caps are parallel and for 220 they are in series because that way you have double the voltage rating and half the current rating (assuming that you need X uF per Amp).

author: eevblogfan
author_rank: Frequent Contributor
timestamp: April 17, 2013, 06:30:11 pm
content: very good chance

author: eevblogfan
author_rank: Frequent Contributor
timestamp: April 19, 2013, 05:23:07 pm
content: Update !lols can't understand why I didn't figure that's the case , the two caps in the ATX are Voltage doubler configuration . so 120 will be multiply by aprox 2 hence 240 .... no dramaI cant belive I've bulshited about that voltage divider made out of caps

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 20, 2013, 02:18:40 pm
content: Quote from: PA0PBZ on April 17, 2013, 04:48:31 pmThat would actually work and is known as a "capacitive voltage transformer". By DC he means the load is a rectifier load. (It should be *before* the rectifier.) As for equalizing resistors, they're not necessary since the load would take care of it. Use two motor run caps (rated for 440VAC or more on a 240V line) large enough that the load current is small compared to the current through the caps and also add a fuse and MOV for protection.A better solution (since you already took it apart) is to just run the bare LEDs from a wall wart.

author: PA0PBZ
author_rank: Super Contributor
timestamp: April 20, 2013, 02:29:13 pm
content: Yes, easy when it is AC, but he said to put them behind the diode bridge...