How hard is it to find the right transformer for led G4 bulbs

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gebbione

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I dont know much about electrics. So far I have replaced all my GU10 halogens to Leds without wondering about Transformers and the like.

With the G4 lights in this bath cabinet https://photos.app.goo.gl/D69SNTbpqtIHLMoH3
I did the same, but here the story is a bit different. The light has this thing called a transformer, obviously new thing for me, and i understand to transform from 240v to 12v, so i just took one out and put the led version that eventually melted all black as you can see from the photo. Now the lights are not turning on, even the old halogen so i assume the transformer is gone too. Still these disk shaped g4 bulbs are 12v.

It looks like these bulbs are 2W and I now need to replace the broken transformer with one that can power these lights. I understand that these are 160mA in power so what kind of transformer can i get able to power G4 12v bulbs from 2 to 4W of power. Is there anything like this and what specifications am I looking for when getting a replacement?

The ones i looked at are all 300mA minimum. (should the transformer also be 320+ because two light bulbs are present ? 160+160?)

Also what is the difference between a transformer and a driver?
 
Do you have more info on the Lamps.
Like the tiles :)

They look like chinese lamps, if theres only 2 fittings, a better option may be measure the cut out and get 2 sealed fittings with built in drivers suitable for the Bathroom Zone
 
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The important bit is the AC and DC
The DC ones will only work with a Driver
Like the 12 volt DC ones sold in screwfix though the lamps need fitting correct polarity.

The AC DC ones will work with a Driver or maybe some Electronic Transformers.
PS ignore any posts from Winston1 slagging off Electronic transformers and if needbe press the ALERT MODERATER button
 
Quick read and it says DC only for disc so will not work with a transformer as these always have an AC output.

You need a power supply with DC output the cob says AC/DC so will work with either a transformer or power supply, what neither advert states is any tolerance I would think you need a supply slightly under 12 volt DC rather than over, it may see odd but with 12 volt because lead acid batteries are often 12 volt we often expect items to work in the range 11 volt to 14.8 volt so it is a bit of suck it and see.

There are devices incorrectly labelled as "drivers" which will likely do what you want, a driver is a current regulated DC power supply used to power LED's but there are also voltage regulated devices which really should be called power supplies but for some reason are often called drivers so google 12 volt LED driver but carefully read the description.
This page is an example note some have minimum output.
 
ericmark said:
Quick read and it says DC only for disc so will not work with a transformer as these always have an AC output.

You need a power supply with DC output the cob says AC/DC so will work with either a transformer or power supply, what neither advert states is any tolerance I would think you need a supply slightly under 12 volt DC rather than over, it may see odd but with 12 volt because lead acid batteries are often 12 volt we often expect items to work in the range 11 volt to 14.8 volt so it is a bit of suck it and see.

There are devices incorrectly labelled as "drivers" which will likely do what you want, a driver is a current regulated DC power supply used to power LED's but there are also voltage regulated devices which really should be called power supplies but for some reason are often called drivers so google 12 volt LED driver but carefully read the description.
This page is an example note some have minimum output.
Click to expand...

Ok none of you guys are actually specific about the Amps. The guy at my local electric shop in Kenton, Harrow just told me that the 350mA that he had might be too much for what I needed and was going to burn them. He told me to look at Maplins but I cannot see anything that matches what i need.

Let's see what you think about the ones i have googled
The last one from Amazon looks alright to me?
 
gebbione said:
The guy at my local electric shop in Kenton, Harrow just told me that the 350mA that he had might be too much for what I needed and was going to burn them. He told me to look at Maplins but I cannot see anything that matches what i need.
Click to expand...
Rubbish, with a true "Driver" yes the milliamps matter often rated 320 mA at 5 ~ 40 volt, but your NOT buying a true driver, your buying a 12 volt power supply and the volts are fixed at 12 volt and the amps will vary according to load so as long as what you have is between the minimum and maximum output of the power supply then it's OK, it does not matter if maximum on the power supply is 500 amp as the voltage is fixed so it will only draw what is required.

So for 2 x 160 mA = 320 mA the 1000 mA supply you have selected should be fine. It is the same as the TLC one linked to, the BangGood one would also work OK you are within the range.
 
gebbione said:
Ok none of you guys are actually specific about the Amps. The guy at my local electric shop in Kenton, Harrow just told me that the 350mA that he had might be too much for what I needed and was going to burn them. He told me to look at Maplins but I cannot see anything that matches what i need.

Let's see what you think about the ones i have googled
The last one from Amazon looks alright to me?
Click to expand...

Where do they get these idiots from in these shops?
 
gebbione said:
I dont know much about electrics. So far I have replaced all my GU10 halogens to Leds without wondering about Transformers and the like.
Click to expand...
Well you wouldn't, as lamps with GU10 bases tend to be 230V..


The light has this thing called a transformer,
Click to expand...
No - it has an electronic transformer:

screenshot_1435.jpg


i just took one out and put the led version that eventually melted all black as you can see from the photo. Now the lights are not turning on, even the old halogen so i assume the transformer is gone too. Still these disk shaped g4 bulbs are 12v.
Click to expand...
12V AC, or 12V DC?

If AC, what frequency?

And where did you buy them, where did they come from?

screenshot_1436.jpg




Also what is the difference between a transformer and a driver?
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These articles cover that - unfortunately they use imprecise terms, but so substitute "12V electronic transformer" for "low voltage transformer" when reading.

https://www.hunker.com/13412754/differences-between-led-drivers-and-low-voltage-transformers

https://www.1000bulbs.com/pdf/understanding-led-drivers.pdf
 
gebbione said:
Ok none of you guys are actually specific about the Amps. The guy at my local electric shop in Kenton, Harrow just told me that the 350mA that he had might be too much for what I needed and was going to burn them.
Click to expand...
Was he selling a constant current supply, or constant voltage? If the latter he was talking nonsense - 350mA would simply be the maximum load the supply could cope with, 4.2W if it's 12V.


Click to expand...
It can't burn anything - it's a 12V supply, 1A is the biggest load it can handle.


Click to expand...
Chinese company - avoid like the plague.


The last one from Amazon looks alright to me?
Click to expand...
A UK company, but new, and how big? Do they have the experience, the skills, and the resources to confirm that what their Chinese suppliers tell them about product safety, certifications and performance is true or not?
 
Today i received the driver and installed it. Attached the disc led bulbs and it seems to work great. I had to make sure i understood how to attach the cable as the old one had a slightly different name and layout, so the new one with PIR and SEC is installed correctly (i think, nothing has blown off this time today)

Thank you all for bearing with my newbie question
 
More likely PRI for Primary thats the mains voltage input and SEC for secondary, thats the output to the lamp.
 
Ok folks, I have another similar problem. Same situation where i want to remove the old bulbs for new led ones.
In this bath I have taken photos of the transformer and electric transformer (there are two boxes here)
https://photos.app.goo.gl/riykkFVmpTwwA7Nj1

You can also see the label for the unit showing that the unit is for 2x 20W halogen bulbs.
The output of the white electric transformer inside the unit (as per photo) is of Max 6.0Amp at 12v

Will this burn the light bulbs and melt too or can I just replace the lightbulbs? What about the other black box with the writing Custom Transformers part number 4451 ...
?
 
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