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roscoe1129

Multiple Amps Or Accesories On Remote Lead

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THank for showing but does it really matters what relay you uses?

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Before using a relay, realize that:

1. Most power amps and processors require between 10 and 20 mA of current to power the turn-on circuit

2. A "bosch" type relay requires between 110 and 120 mA of current to power the coil

3. Most source units are capable of between 250 ma and 500 ma or current on their turn-on leads (this will be specified in the owners' manual)

Finally, connecting a relay as shown to the turn-on output of a source unit could actually damage it. I would strongly recommend installing a diode across the coil of the relay (in reverse bias - stripe side to turn on lead and non-stripe side to ground). When power to the coil of a relay is turned OFF, the electromagnetic field within the coil collapses. This can in some cases result in a very large voltage spike traveling up the turn-on output of the source unit, which could damage it. The diode will shunt this spike to ground, thereby making the addition of the relay harmless.

Some auto relays have a diode across the relay already. Would these types be good enough to use?

Edited by David12460

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Before using a relay, realize that:

1. Most power amps and processors require between 10 and 20 mA of current to power the turn-on circuit

2. A "bosch" type relay requires between 110 and 120 mA of current to power the coil

3. Most source units are capable of between 250 ma and 500 ma or current on their turn-on leads (this will be specified in the owners' manual)

Finally, connecting a relay as shown to the turn-on output of a source unit could actually damage it. I would strongly recommend installing a diode across the coil of the relay (in reverse bias - stripe side to turn on lead and non-stripe side to ground). When power to the coil of a relay is turned OFF, the electromagnetic field within the coil collapses. This can in some cases result in a very large voltage spike traveling up the turn-on output of the source unit, which could damage it. The diode will shunt this spike to ground, thereby making the addition of the relay harmless.

Damn now that i've read this im scared lol... Should I use a relay or not? Cuz I donno wtf a diode is so I will not have one...

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Damn now that i've read this im scared lol... Should I use a relay or not? Cuz I donno wtf a diode is so I will not have one...

you can buy a diode at radio shack, i think a 2 pack is $1.99. but the relays i have now already have a diode across the terminals on the bottom

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hmm im quite stupid, cause i didnt really understand that one lol. i know what a relay is and everything, but not exactly how id run more than one remote wire from amps to it, and which relays to use, and how much to even fuse the remote wires for lol

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I didn't realize this thread had sparked so much confusion since I posted almost a year ago. This topic is really quite difficult to explain in a forum thread. But, I cover relays and diodes in great detail in my book Automotive Wiring and Electrical Systems. I also dedicated a third of a chapter to the use of a Digital MultiMeter (DMM). Within my discussion of how to use a DMM, I show exactly how to determine the current requirements of nearly anything - including the turn-on circuit of an amplifier.

Pick up a copy of the book and you'll have my over twenty years of experience in car audio at your fingertips. I promise you that your money will be well spent!

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I realize this thread hasn't had activity in a while but I have one question to any one who can answer it.

In using a relay, couldn't SPST relay be used instead of a SPDT?

I only ask because even with the SPDT relay, only one of the two contacts is being used.

Or does the SPDT relay have something over the SPST relays that is needed?

Thanks.

EDIT: Used a SPST relay. Works just the same.

Edited by MAG-nanimous

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I thought I would be cool and order up some nice sockets for my relays I'm adding....... Now I get the fun task of rewiring them so they fit my needs.

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