On Sun, 27 Nov 2016 11:30:29 +0000, (Roger Hayter)
wrote:

Scott wrote:

On Sat, 26 Nov 2016 22:57:58 +0000, (Roger Hayter)
wrote:

[snip]

If they are toroidal mains transformers (with no switched electronic
supply) they will be perfectly happy with the LEDs. The problem is that
if the transformers produce 12V AC and the LEDs require 12V DC the LEDs
won't work.

I was planning to use AC LEDs and not to buy the cheapest I can find.
As an alternative, I did wonder if I could fit a rectifier after the
transformer output but Mr Google suggest this might produce a
fluctuating voltage.

Depending what sort of rectifier it will produce 100Hz or 50Hz flicker,
which some people at least will find intolerable, and will reduce
brightness. There are design criteria for DC power supplies, and you
could no doubt build one, but by the time you dealt with electrical
safety considerations it would be quite a project and cost more than
getting a commercial LED power supply.

Thanks. Then I will stick with AC LEDs :-)