On Wed, 15 Apr 2020 11:23:53 +0000, John wrote:

I fitted a couple of G4 LEDs in a Cooker Hood. They flicker a bit - I
suspect they are under-loading the power supply.

Yes, I have a fitting with 6x 12v G4 20w halogen lamps.
It would not even light up with 6 x 4W led lamps in it.
Basic, wound, transformers will be fine, as they always give out power, a
lot of the solid state ones cannot detect the low wattage required by LED
lamps, so do not work.