Thread: inrush current
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Default inrush current


"Scott Lane" wrote in message
...

"Wiebe Cazemier" wrote in message
...
Hi,

A friend of mine is trying to repair an active woofer of a speaker set,
which
started to blow out the primary fuse suddenly. The problem would appear
to be
in the torroidal transformer, because even when nothing is connected, the
fuse
blows. We decided to be stupid and put in a 2A instead of 1A fuse. It
didn't
blow, and the primary current was only 20 mA. All secondary voltages were
normal. (two assymetric outputs, and one symmetric with center tap).

So, it would appear the inrush current is very high. But, because the
device
worked normally in the past, it would appear that the inrush current
suddenly
increased. Is this possible? To be more precise, is this possible when
all the
secondary voltages are normal? If so, how?

Thanks in advance.

Sounds like a shorted woofer coil. Sometimes they won't show a short until
you 'push' on the cone, or until it moves when you apply signal to it.
Scott

I rather think not, as if you read the whole thread, you will see that the
OP has carefully stated, on more than one occasion, that the fuse is blowing
with absolutely nothing connected, except the transformer primary ...

Arfa