On Tue, 14 Jul 2009 12:08:38 -0700 (PDT), Vet Tech wrote:

Can someone, who knows about electricity theory please explain the
reasons behind this limitation. And, if more than 3 were connected,
what would happen?

Real transformers as in lumps of iron with wire warpped around them
have fairly hefty inrush currents, toridial (donut shaped)
transformers commonly used in lighting applications have really big
inrush currents. They also produce a spike when switched off. Either
or both of these could kill the semiconductor switch in the dimmer.

Are your lighting transformers large and heavy (lumps of iron with
wire) or small a light (electronic power supplies)? The latter won't
have the inrush or spikes but they might object to being dimmed...

--
Cheers
Dave.