Strange mixer inputs

[KA4HJH]

>Apparently, these big monitor speakers have a fuse and a mini light bulb for
>protection. The fuse was fine, but one of the light bulbs was marginal! I am
>not sure electrically what the light bulb is being used for, but the problem
>was tracked down to that and replacing it did the trick!

Sounds like a ballast. Non-linear thermistor.

There was a guy whose model train kept derailing and shorting out his 
electronic throttle, frying transistors, blowing fuses, or tripping 
breakers constantly. He was too lazy to fix the track, but 
fortunately a friend suggested putting a 12V taillight bulb in series 
with the throttle. Now every time there was a short the filament 
heated up from the increased current, increased its own resistance, 
and limited the current enough to prevent anything from blowing.

Don't know if that's what's going on here but it's a good story.

Terry Bowman, KA4HJH
"The Mac Doctor"

ICQ: 45652354