Author Topic: Fixing a 240v Led bulb (Read 3710 times)

guruji · « **on:** July 14, 2006, 02:39:06 PM »

Sir I have a 240v led bulb which it have gone dim I don't know why.When I opened it there is a 400v 200nJ resistor and other small resistors.Can someone tell which of these have to be replaced?.

Thanks.

jimjjnn · « **Reply #1 on:** July 14, 2006, 09:58:41 AM »

400V 200Nj ? sounds more like a capacitor

Nando · « **Reply #2 on:** July 14, 2006, 10:30:43 AM »

YOU have not indicated enough information

The 220 nf / 400 volts is a Capacitor that is used to reduce the power usage.

You should have a Zener diode, and 4 diodes or a diode bridge Rectifier and 2 or 3 resistor.

One SURGE resistor, around 1 watt size and with a value of 1 or 2 Kilo-ohms, then the biasing resistor for the LED or LEDs after the diode rectifiers.

The ones I have designed :

220 volts in (hot) = Capacitor + surge resistor + diode bridge ( AC side) = 220 volts neutral

Then Inside the bridge rectifier( DC SIDE), Positive to Zenercathode, Negative to ZenerAnode , then resistor from ZenerCathode + Anode-of-LED -- Cathode LED to ZenerCathode.

Normally, if the CKT dims is because the SURGE resistor may have increased in value due to over heating or Zener diode problems, lastly the resistor & LED may have been damaged as well.

Nando

guruji · « **Reply #3 on:** July 14, 2006, 12:10:03 PM »

Hi Nando thanks for the info I am not a technician that's why I called that a resistor.So in your opinion it cannot be fixed.

Thanks.

Nando · « **Reply #4 on:** July 14, 2006, 12:48:38 PM »

I do not know if it can be repaired or not, you need measure the SURGE resistor and see what value is.

Also one needs to measure the Zener diode voltage and the LED voltage = 1.8 to 2.2 volts .

Nando

guruji · « **Reply #5 on:** July 15, 2006, 07:03:34 AM »

The thing is that I don't recognize the surge resistor or the zener diode.Although I know which are the resistors and the diodes.I measured in ohms the capacitor I don't know if it's right to measure capacitors.It read about 1008 and there was another resistor with same reading.I really would like to fix these bulbs cause they cost me a little.

Thanks anyway Nando.

Nando · « **Reply #6 on:** July 15, 2006, 10:41:41 AM »

The capacitor WILL READ, if good, 1000 + megohms.

The Surge resistor is next to the capacitor, I can not tell you the value or range because you have not given enough information to do an analysis.

The surge R may vary from 1000 to about 4700 ohms and most ot the time is the critical one.

It may be the bad reading of the resistor you say it is the same to 1008

Nando

guruji · « **Reply #7 on:** July 16, 2006, 01:44:44 AM »

Ok the capacitor is reading 1008kohms;there are three resistors one is reading 1006kohms;386ohms and the other 99ohms.I checked the diodeswith a 1.5v battery, all are working although they're giving a bit less about 1.25v.

Is it maybe one of the resistors should give more maybe?

Thanks.

Nando · « **Reply #8 on:** July 16, 2006, 09:00:29 PM »

The 1006kohms is not good and that one should be in series with the capacitor, unhappily you have not tried to draw the circuit, not you have indicated how many diodes, some have 5 each or one with 4 leads and one with 2 leads

Checking configurations it seems that the 99 ohms is in series with the LED .

Change the 1006kohms for a 1800 ohms, 1 watt resistor and check how brilliant the LED is .

Nando

guruji · « **Reply #9 on:** July 17, 2006, 03:21:16 AM »

Hi Nando thanks for the info there are four diodes.So do you think that 1006kohm resistor is faulty?Can you please tell me what part number is that to buy it from an electronic shop cause when ever I go buy a part this guy always ask me for part number of the electronics and sometimes I cannot buy these parts.

I thank you in advance.

Guruji

Nando · « **Reply #10 on:** July 17, 2006, 08:29:22 AM »

The part number is : 1800 ohms , 1 watt 5 % resistor

Also anything from 1200 to 2200 ohms will do : 1200, 1500, 1800, 2200 ohms

Nando

guruji · « **Reply #11 on:** July 17, 2006, 11:44:05 AM »

Another thing Nando please can you give me part number of skotkey diodes for solar panel?

Thanks for everything.

Nando · « **Reply #12 on:** July 17, 2006, 04:26:39 PM »

Guruji:

You need to LEARN to give information for anyone to be able to assist you -- your statement does not say anything but you need a Schttokey diode, there are thousands and NO body knows what you need, because NO body knows what you have.

INFORM in detail

Also, let's know if your lamp was repaired or NOT !!

Nando

guruji · « **Reply #13 on:** July 18, 2006, 04:02:38 AM »

Ok Nando you're right I will try to fix those led bulbs and for sure I let you know.About skotkey you said that there are thousands that's the problem that I did not know that there are thousands.

I was reading and this guy was saying that better use skotkey diodes for a solar panel than normal diodes between the panel and the bank cause they have less loss of voltage.I went to tell this electronic guy shop and he told me that he wanted part number and I stayed infront of him like this :0

hahaha it's true cause sometimes it's like talking chinese to me as I told you I'm not an electrician.Hope you understood what I want otherwise don't worry you've been more than enough of help.

Thanks again.

Nando · « **Reply #14 on:** July 18, 2006, 07:24:20 AM »

Let's try again.

Where are You located ?

You need to SUPPLY information of WHAT YOU HAVE to be able to assist you -- you go back to the SCHOTTKY -- I know the SCHOTTKY DIODES - but I do not know what you have to fix.

So inform in a proper manner -- DETAIL WHAT YOU HAVE -- the whole thing !!

Nando

guruji · « **Reply #15 on:** July 18, 2006, 11:14:14 AM »

Hi Nando I am in Malta Europe.I have a 10w solar panel and would like to do a diode with the bank of batteries.If this type of diodes skotkeys are better than other diodes I would use these with future solar panels.

Hope I was clear cause it shows that contact is getting a bit difficult.

Tell me what you want to know exactly Nando regarding my solar panel?.

Thanks.

Nando · « **Reply #16 on:** July 19, 2006, 11:41:51 AM »

Guruji:

The contact is very difficult because you do not communicate fully, it seems that you assume that I or all in the group can read your mind.

Question made with generalities get generalities as answers -- because one can not give you an accurate answer to your needs if your question does not inform fully.

Like the SCHOTTKY question which is done with generalities for future use and to answer you I would need to give you a long list of diodes with explanation for each diode or case, I do not like to write books for such answers.

I do not have the diode nomenclature for the European types.

For a 10 Watts get a SCHOTTKY diode at least 1 amp and 30 Volts -- there are many values in Europe and or the world that change nomenclature depending on the country or world Zone of interest.

Check for 2, 5, 10 amps with 30 volts breakdown and buy one with the highest current you can afford.

For panels with higher current, use one that is at least 3 times the current of the panel -- to reduce the voltage drop to a minimum.

Nando

guruji · « **Reply #17 on:** July 19, 2006, 12:33:11 PM »

Thanks Nando it's true but as you said my mother language is not english and these electronics I don't know nothing on them,I am a musician not a technician but it's ok; still you understood what I wanted.

You have a great mind Nando for electronics and communication good good.

Great minds Great humbleness Great communicators.

Nice keep it up man.

Thanks.

guruji · « **Reply #18 on:** July 20, 2006, 09:03:10 AM »

Nando no luck about the led bulb it did not work I changed that resistor but invain.The leds were very dim now.Leave it now better luck next time.

Bye bye.

stevec5000 · « **Reply #19 on:** August 31, 2006, 01:29:41 PM »

It's common for white LED's to get dim in just a few weeks of continuous use.

I know they always say that LED's last a long time, thousands of hours usually,

but that's a lie. Red and green LED's usually have a long life but white and

blue ones do not. I've been struggling with this problem myself and I've tried

4 different kinds of white LED lamps but they all go dim in just 2-3 weeks.

Some get really dark sooner than others but they all tend to turn a bluish

purple and get dark and keep getting darker the longer they are on.

The only solution I've found is to get new LED's and replace the old ones,

however, the new led's don't last any longer than the original ones did

in the case of 5mm LED's.

One solution I'm considering is switching to a new type of surface mount

LED that is much brighter and also is supposed to have a longer life,

the LUXEON I 1 Watt LED from Philips that is used in high power flashlights.

They are relatively cheap since being replaced by the more powerful LUXEON 3 LED, $2.95 each from Tek-Tite.com, http://www.tek-tite.com/src/product_info.php?id=2985.

The data sheet is available here, http://www.luxeon.com/pdfs/DS25.pdf

The LUXEON I LED's are very small and put out a lot of light and are rated

by Philips to put out 70% of lumens at 50,000 hrs but are not

directly interchangeable with the older 5mm LED's since they use 350ma

of current, not 20ma and get hot so they have to be glued to a heatsink for

cooling. For these reasons they wouldn't make good replacements but need to

have a new lamp designed to use them. I'm thinking of using a switching supply

with 12-15V. DC output to power 3-4 LUXEONs in series.

I'd be interested in knowing if anyone has any better ideas or if you

have run across any white 5mm LED's that actually last very long that

would be good for replacements in dim LED lamps. Thanks.

ghurd · « **Reply #20 on:** August 31, 2006, 04:07:33 PM »

See what I said in your other post.

http://www.fieldlines.com/story/2005/10/5/223956/664

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Author Topic: Fixing a 240v Led bulb (Read 3710 times)