"Can I make the mute mode activate the second there is DC on the output?"
And this would do what?
This is a crowbar:
http://www.diyvideo.com/forums/attachment.php?postid=49718
If the amplifier is FUBAR the mute circuit or the SPIKE circuit will not protect the speaker.
If you did something to cause the DC that you can correct, the SPIKE circuit in the chip will protect it from the crowbar.
And this would do what?
This is a crowbar:
http://www.diyvideo.com/forums/attachment.php?postid=49718
If the amplifier is FUBAR the mute circuit or the SPIKE circuit will not protect the speaker.
If you did something to cause the DC that you can correct, the SPIKE circuit in the chip will protect it from the crowbar.
soundNERD said:
Try out UPC1237. This is a simple speaker protection circuit.
http://www.promelec.ru/pdf/upc1237ha.pdf
No, about the input connection, The resistor to ground is soldered across the end of the input wires, not the board. So, if the wire would break, then the input is floating, and the output on the speaker goes to about 20V. So, when that happens (which it has) I want the mute to flip on to protect the speaker. I know if the amp fails, then the mute pin wouldn't stop the DC, but that I am not worried about.
Actually, if the speaker has a fuse, will it blow if there was any large voltage on the speaker?
Actually, if the speaker has a fuse, will it blow if there was any large voltage on the speaker?
Mute circuit
How about this, connect a relay between the mute pin on LM3886 and the negative supply and activate the relay (to open it) whenever you have a lot of DC show up on the output, like 20V.
Use a relay activated by a high voltage (12-20V) and just connect the ouput to this relay The relay will certainly be activated by 20V, just make sure in normal operation you don't exceed the relay activation voltage. I suppose you could drop the voltage with a resistor to use a more sensitive relay. Now resetting the relay may be interesting but if you choose the right type of relay it may reset itself when the voltage goes below the "set" threshold.
How about this, connect a relay between the mute pin on LM3886 and the negative supply and activate the relay (to open it) whenever you have a lot of DC show up on the output, like 20V.
Use a relay activated by a high voltage (12-20V) and just connect the ouput to this relay The relay will certainly be activated by 20V, just make sure in normal operation you don't exceed the relay activation voltage. I suppose you could drop the voltage with a resistor to use a more sensitive relay. Now resetting the relay may be interesting but if you choose the right type of relay it may reset itself when the voltage goes below the "set" threshold.
First, why should the wire break? I assume that your amp looks tidy inside. It's not very good the either of the inputs float but see to it that this never happens. If you are worried about this pulldown resistor I'd suggest that you connect it closer to the IC. My advice to you is to make good connections everywhere. The LM38xx is very safe and hard to destroy _if_ it's connected properly.soundNERD said:
If would probably not protect for harmful DCsoundNERD said:
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