15 May
2007
15 May
'07
2:38 a.m.
Apparently, you may not realize that a variac can burn up too--variacs
cost a pretty penny. The current limiter is a preventive measure.
Switched mode power supply designs are used in many applications,
beginning with of all places, a modern computer monitor. Variacs have
proven to be a valuable tool to diagnose a lot of symptoms.You may want
to research this small bit of troubleshooting methodology even further.
I wouldn't like to think all our repair manuals have been erroneously
filled with uneducated gibberish.
:)
=Dan
resistance
thus reducing the current. When a unit is functioning
properly without any shorts at nominal voltage, the bulb will just have
a faint dim.This is the oldest trick in the book.
Not so fast...
If you'll re-read my original post on this, my question related not
to using a current limiter in series with the variac, but using one
in lieu of the variac. As many have pointed out, running a SMPSU
from a variac may not produce the desired result.
In fact, I'm wondering if an incandescent with a tungsten filament
alone is best for this, rather than, say a carbon resistor with a
negative temperature coefficient of resistance, which might
ameliorate the inrush current. One could then use an incandescent
for current limiting once the inrush problem had been dealt with.
Any thoughts on this?
Cheers,
Chuck