3x MR11 LED’s faintly flicker, suspected transformer issue.

[LenBeach]

My girlfriend recently bought a house and we changed all bulbs to LED’s for both energy efficiency reasons and as some were blown.

Under the kitchen cabinets were 3 MR11 halogen bulbs, 2 of which were blown. I replaced these with 3W LED’s which work but faintly flicker.

On investigation, the remaining halogen bulb worked in all 3 light fittings confirming there’s not a wiring issue. All 3 bulbs are wired into an old Elektra ET60F1. These appear to only be available overseas but on reading/translating the text on the transformer it reads:
230v ~ 50/60Hz 0.25a ta 50°C SELV equiv 11.5V ~ 10-60W wavelength 0.9 halogen lamps with max. 2m cable

I assume as I have 3 bulbs at 3 watts coming in at 9 watts on total which is below the minimum 10 watt operating range, this is leading to the flickering and I’d need to swap for an LED driver?

The Elektra has provisions for up to 6 fittings powered by the 1 unit, what would be a suitable LED driver equivalent to power all 3 lights?

E-Trafo Leuchtenset m.Scha. 230V 12V/60VA ET60f

Elektronischer Sicherheitstransformator ET 60f 10-60W Dieser elektronische Sicherheitstransformator der Marke ELEKTRA versorgt Halogenleuchten mit integriertem Schalter (z.B. Dreieckleuchten) mit der richtigen Spannung.

b2c.elektra-shop.de

Thanks in advance

 

[ericmark]

Many LED's are designed for 50 Hz AC, toroidal lighting transformer does not care if 1 watt or 60 watt, only electronic transformers have a lower limit, modern electronic transformers will go to zero, as to if worth continuing with extra low voltage it depends if there is an earth, moving to low voltage (230 volt) often means you can use smart bulbs etc. Not sure with MR11, but may want to look at using 230 volt bulbs first.

 

[LenBeach]

Magic, thanks for your help. I’ve ordered an LED driver which I’ll try before moving to 230v bulbs.

 

[Why Not Indeed]

I repaired a "Serious Readers" lamp that had an AC transformer built in. Tried LED bulbs in it, one was fine on AC, the other flickered just enough to be annoying. Shoehorned a 12V DC transformer into it, both bulbs now fine.

 

[ericmark]

I had the problem with G9 bulbs, 230 volt, the bulb is that small to fit inside the covers there is no room in the bulb to fit a smoothing capacitor, larger versions do have the capacitors, but can't fit the cover on them. I would guess the same problem with the MR11, using a smooth DC supply they would not need a smoothing capacitor inside the bulb, but the big question is what is inside the bulb? To limit the current the bulb can use resistors, capacitors or pulse width modulated controllers, and we have no idea what is inside the bulb.

At 12 volt unlikely it uses a capacitor to limit current, but my MR16 bulbs from Lidi were clearly marked 50 Hz, which would lead one to consider a capacitor may have been used, it could have also been to stop bulb becoming a transmitter, but if able to use DC one would not have expected it to be marked 50 Hz.

I have not reverse engineered any bulbs marked 50 Hz, so only guessing, moved house and no longer have any extra low voltage bulbs.