The reason that it *might* be bad is that the vast majority of solid state dimmers have large chokes in series with their outputs. The function of the
choke is to retard - or '
choke' - rapid, large changes in
current. Normally what this does is reduce
incandescent lamp noise when running ~ 50% by reducing inrush currents when the
triac fires near the peak of the
sine wave. The potential problem in the case of a moving light, for instance, or a
scroller power supply, is that these sorts of devices use switch-mode
power supplies. The very first
stage of an
SMPS is to rectify (using, ie, diodes) and smooth (using capacitors) the incoming (typically AC)
power to create a DC bus. As a result, an
SMPS does not draw any
power until the supply
voltage exceeds the
voltage of the DC bus plus the
voltage drop of the rectifiers, after which
point it can draw a significant amount of
current. So an
SMPS inherently has a large, sudden increase in
current draw 120 times a second (assuming a 60Hz supply).
Now, if the
SMPS is drawing a large amount of
power, then that sudden increase in
current might be enough for the
choke to react to, so the
choke may '
choke' the SMPS--restrict the latter from drawing the
current it needs. If that happens, then the DC bus
voltage will sag, and the next
stage of the SMPS--where the DC bus is inverted at high frequency and transformed to whatever lower
voltage is required--must increase its duty cycle to keep the output
voltage up, which is harder on the components in that
stage and may lead to their premature failure. In the most severe cases, or if the
SMPS is smart enough, it will simply shut off.
On the other
hand, if the
SMPS load is small enough, or a small enough fraction of the total load, then you will be just fine because the
SMPS is so tolerant of incoming waveforms due to that rectification and smoothing in the first
stage.
That all said, if you have a dimming
system with interchangeable dimming modules (ie
ETC Sensor), your best bet is to swap in
relay modules for any circuits that will
power anything other than an
incandescent lamp.