Led down lighters flickering

[Guitar_man]

Swapped my kitchen halogens gu 5.3s, 3 in parallel, wired off a 12v lv transformer for b and q leds(as I can't seem to get halogens).
However the lights flicker after a time and go out eventually. I bought another transformer, swapped it out. Same problem. Also rewired the lights now with new cables
Any ideas? Am I missing something?
Cheers,

 

[davelx]

Can we have a photo of the transformers, and details of any markings. Suspicion is that they are switched mode psus with a minimum load rating which the new leds do not meet.

 

[winston1]

You need LED power supplies to power LEDs.

 

[delmel]

Anything in B&Q which is Led is unlikely to be much good in terms of quality and especially performance. LED have drivers not old low voltage transformers which although if extremely good ones may work but will always be less efficient and cause earlier led failure. Consider converting to GU10 as the LED lamps are much more widely available and easy to change also have drivers built in. Again make sure its a good one or you will be dissapointed

 

[Guitar_man]

Will photo today. I have 3 new leds. All flicker. Surely they are all not faulty. Will photo the transformer today. But again both exhibited the same problem. The leds are pretty hot to to the touch when they flicker. They also flicker when only two are connected. Note the don't flicker unless they have been on a while. Not impressed so far with new led tech. They're expensive and dont appear to work!

 

[bernardgreen]

Not impressed so far with new led tech. They're expensive and dont appear to work!

LED ( Light Emiting Diode ) technology is good. An LED is a small component that converts electrical energy into light

A lamp is more than just an LED element,

Lamps that mis-use the technology and/or incorrect installation create the problems. Mis use of terms like driver, transformer, power supply confuse the matter

A lamp with nothing but an LED element ( or elements ) needs a controlled DC current supply from an external driver, the driver must control the current through the LED element and not the voltage supplied to the LED element. The voltage that appears across the terminals of the LED element ( or elements ) is determined by the LED element(s) and NOT by the driver.

A lamp with an LED element ( or elements ) and an integral driver requires a voltage controlled power supply. The integral driver in the lamp will determine how much current flows through the LED element(s)


Some integral drivers require an input of 230 volts AC, some require an input of 12 volts DC,

 

[Guitar_man]

Pics

 

[flameport]

That transformer is designed for halogen lamps with a minimum load of 35W. It will not work properly with LEDs.

 

[winston1]

Will photo today. I have 3 new leds. All flicker. Surely they are all not faulty.

They are not faulty. Read my post number 3:

"You need LED power supplies to power LEDs."

 

[bernardgreen]

You need LED power supplies to power LEDs.

You need a power supply to power lamps that use LEDs using an integral driver for the LED elements

 

[Guitar_man]

Ah, so the transformer needs to specify for Leds. Makes sense! The guy sold me the wrong things. So I need a bulb with the driver integrated into the fitting?

 

[winston1]

Ah, so the transformer needs to specify for Leds. Makes sense! The guy sold me the wrong things. So I need a bulb with the driver integrated into the fitting?

NO. You want a DC power supply or LED driver, not a transformer. All LED lamps have drivers integrated in the fitting. With GU10 types the (internal) drivers expect 240v, with GU5.3 types the (internal) drivers expect 12v DC or (sometimes) 12v AC 50/60Hz. Halogen power supplies (like yours) run at tens of kHz which can damage LEDs designed for DC or 50/60Hz.

 

[bernardgreen]

Winston..... If the lamp has a driver integrated into the lamp then the supply external to the lamp cannot be a driver.

A driver forces a set current through the load ( LED element ). That current forced into the lamp can destroy the driver inside the lamp.

 

[Guitar_man]

So I need to take the transformer back to the shop and ask for one suitable for Leds?

 

[winston1]

Winston..... If the lamp has a driver integrated into the lamp then the supply external to the lamp cannot be a driver.

A driver forces a set current through the load ( LED element ). That current forced into the lamp can destroy the driver inside the lamp.

If you say so. So you are saying a driver is a constant current device? What is often sold as a driver is generally a DC power supply (constant voltage).