"Jim Lesurf" wrote in message
...
In article , Graham Holloway
wrote:


"Pooh Bear" wrote in message
...


One of the fuses will blow before the other.

What happens to the voltage at the speaker output then? And could it
toast the speaker?

Sounds well dangerous to me.

Far more reliable is to fit 'crowbar protection' on the output to
guard
against
excessive DC. Whatever else - the speaker won't see prolonged DC.
Supply
rail
fuses will blow.


Graham


If either fuse blew, the output would float to zero.

My experience was similar. I tried various kinds of 'problems and faults'
on the designs I played with and they tended to either:

1) Blow one fuse and the output floaded down to zero with no real ability
to o/p current.

2) Blow both fuses almost at the same moment.

I assume this depends a lot on the design details, but I concluded that I
could omit any d.c. crowbar, etc and just depend on the fuses. My concern
was more for the amp than the speakers, though... 8-]

Slainte,

Jim

--
Electronics
http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Jim

My boss was more concerned about £10 amplifiers failing, followed by a claim
for £100 speaker damage.

Graham