On 11/16/20 1:50 PM, Chuck wrote:
I've been reading about dimmers here and thought I would try dimming my
outdoor LED lights with one of the Chinese 12-24VDC 30A PWM dimmers
found on eBay and elsewhere.Â* The lights are running at 12VDC and
consume 8.5 A.Â* Dimmer was installed, but noticed right away that it was
very warm.Â* In an hour, almost too hot to touch.Â* Should not have been,
not at the current levels I noted.Â* After several hours, it began to
smoke and burn out.Â* In the meantime, lights went to full brightness and
probably then some.Â* Needless to say, the only way I'll be using any
more of these is with an in line fuse as well.Â* Of course, the dimmer
doesn't have one inside.

That's it, no more Chinese dimmers! I just can't trust them. This
week, I managed to pick up a linear variable voltage and current Astron
12 amp power supply. It won't be as efficient as switching units, but
Astron is apparently a winner with amateur radio folks and reviews tout
its reliability. I looked at the schematic and it seems that all of
their units use the same general design, just different transformers and
components of course as size increases. I like the fact that the
schematics are readily available unlike this Chinese stuff where it is
next to impossible to find one! I have even been able to peek at
several internally online of course, but apparently people often tweak
and modify them and post images and such online. Nice to see the innards.