Speaker Protector With MOSFET

[IrishboyM4]

Any thoughts on a speaker protector using a MOSFET.

Here is one I designed. Uses a SCR as a trip controller.

http://byrne.isa-geek.com/brendan/protector.bmp

[ifrythings]

I'm not the best with this kind of stuff, but I'll give it a shot.

The AC loss detect looks fine, but won't do anything if the SCR is limited by a 2.2M resistor (I don't beleive it will trigger), same goes with the DC detect.

The DC detect system doesn't make sense to me so I'll let someone else coment on it.

Theres no need for a 8 ohm resistor on the relay, why have one end of the speaker grounded and the other go through an 8 ohm resistor to ground, makes no sense to me.

P.S I re-did your schematic, I was having a hard time reading it.

[IrishboyM4]

The SCR is designed to take the bias from the mosfet. It does trigger and the 2.2Mohm resistor and the 16uf capacitor are just a time delay for the turn on.