23 Dec
2010
23 Dec
'10
8:37 p.m.
Agreed! My favorite is a series lamp in the 40-300W
range to limit
current and run the SMPS
with a light load (10% of rated). If there is a short the lamp lights
to limit current and all is good
it's dim or no glow.
Yes, I do that too. I also use a ;series light bulb' with unknown linear
supplies, it saves my nerves if the transformer has shorted turns or
womething. IT may also protect a lienar supply's transfdofmer from
further damage if there's a shorted rectifier or similar.
For SMPSUs I have a pair of240V bulbs in seres which I connect in the +ve
DC line between the mains smoothing caapciotor and the chopper circuit.
This will limit the chopper current if something goes very wrong, andf
while it may not save the chopper transistor, it will stop tracees
getting blasted off the PCB.
Of course owing to daft EU regualtions, cuitable ight bulbs are getting
harder to find. Idiots!
And as I said in my messag,e I'm with you andEric, I would never try to
'run up' an SMPSU on a variac.
-tony