Halogen to LED

pheran

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Anxious to reduce the demands on the domestic battery bank, I am in the process of changing the halogen bulbs in the 8 main cabin downlighters with LEDs (12 element, G4 fittings). I naively assumed that the LEDs were like the halogens, ie it doesn't matter which pin is connected to + or -, but on those I have bought, it obviously does!

So, it seems I am stuck with reversing the supply cables on each of the fittings, unless I can locate some central point covering them all, which after a cursory look, doesn't seem likely. Or has someone got a better idea..........please!
 

Chris_Robb

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Anxious to reduce the demands on the domestic battery bank, I am in the process of changing the halogen bulbs in the 8 main cabin downlighters with LEDs (12 element, G4 fittings). I naively assumed that the LEDs were like the halogens, ie it doesn't matter which pin is connected to + or -, but on those I have bought, it obviously does!

So, it seems I am stuck with reversing the supply cables on each of the fittings, unless I can locate some central point covering them all, which after a cursory look, doesn't seem likely. Or has someone got a better idea..........please!

I thought G4 bulbs just had pins, which can be put in either way round - just put them in the other way round????
 

pheran

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I thought G4 bulbs just had pins, which can be put in either way round - just put them in the other way round????

G4 do indeed have pins. But because the LEDs are polarity sensitive, the only way they will work (on my set up) is if I put the platter on which the LEDs are mounted into the downlighter housing upside down!! Sort of defeats the objective! ;)
 

pheran

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I suggest buying some more, this time with a full-wave rectifier in the input. This allows them to work with either polarity.

If you give me a link to the type you want, I'm sure I can find you some.

These are the type I now have (off eBay).

G412SMD5050LED.jpg


http://www.ebay.co.uk/itm/111145541...eName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Many thanks for your offer of help.
 

Plevier

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I have used some like that but you get noticeably more light from ones with 9 x 5630 chips like these http://www.ebay.co.uk/itm/390816609627?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

One of the photos of those shows a bridge rectifier on the back, but the text says polarity sensitive which is contradictory. I'll find out the truth when they arrive, hopefully next week.

If you need any end pin G4 ones I have just bought a trial one of these http://www.ebay.co.uk/itm/151258008...eName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 and it is excellent but a bit less light than the 10W halogen. Nicely encapsulated and an even light spread.
Nicely packed in a smart little box labelled "LED Blub"!
I have also ordered some of http://www.ebay.co.uk/itm/151268823...eName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 similar design but twice the power.
 
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These are the type I now have (off eBay)...
For less than a quid each I doubt you will get more than the basics.

These ones will do what you want, but are a lot more expensive: http://amzn.to/1j0rWha

I suggest you desolder one of the wires and replace it with a longer one, looping round the other to reverse the contacts. You might even get away with re-using the same wire, they are normally too long. Put a dab of epoxy on the loop to hold it in place.
 
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pheran

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Many thanks for all the suggestions. Looks like I'm going to take off my cheapskate hat and buy something more expensive!!

In the meantime,and as a experiment, I am quite taken with Nigels suggestion that I could

....desolder one of the wires and replace it with a longer one, looping round the other to reverse the contacts. You might even get away with re-using the same wire, they are normally too long. Put a dab of epoxy on the loop to hold it in place

The pins on those I bought are indeed too long and would need trimming back anyway so I'll give it a go. At less than a quid each, it isn't really going to matter if I make a complete b*lls-up, and who knows, it might just salvage something from what it seems might have been an unwise purchase.
 
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