Me too. Real easy and works flawlessly.Originally Posted by rando
I just use the +12v output from the PSU to turn on my amp. It works without any problems. I suppose (depending on the internal switching circuitry of the amp) this could be a bad thing for the PSU. If you're paranoid, hook your +12v battery lead to the amp turn-on signal through a relay. Switch the relay with th +12v output from the opus. Throw in a diode across the relay coil to make things even safer.
Not to upset anyone, but as far as a ground larger is better but not necessarily needed. The load (i.e. the amp) is before the ground. In witch case the amperage is consumed by the load, and if you measure current flow on the ground side of a circuit you should find only milliamps. If you find a larger amount then you should check for a voltage drop in the ground side, this is done by using a VOM. With the VOM set to 12 volt scale connect the positive lead to the ground side of the amp at the terminal. Then the negative lead to the negative side of the battery. Now power the amp and this will show the amount of “voltage-drop” in your ground wire. This should be less then 0.1 volts. POWER DOWN THE LOAD (your amp). Then now switch the meter to the 10 amp scale and the lead for the positive at the meter also to the 10 amp port. Power on your load and you will see the amperage drop in your ground this should also be less then 0.1 amps. You will also be able to watch start up draw ( the amount needed start your circuit ) If any of you reading are greater then this you will need to find a better ground location or move to a larger ground wire.
As for powering from the power supply I would always use a relay or transistor. Just to prevent a failed amp from doing damage to your power supply. Just image your amp goes bad shorts to ground (or the wire get shorted on is way to the amp) boom, boom out go the lights. If hard drive looses power on a write now you have data loss.
There will be he same current flowing thru the ground wire that is on the power wire. The current doesn't "get consumed". It's not really a physical thing. Current is the term for electrons moving thru a circuit. The same number of electrons that leave the neg side of the batt, go into the positive side.Originally Posted by lawrence
When you hook up the meter in parallel like that, you aren't measuring the current going thru the ground wire. You are only measuring the current that would rather find it's way thru the meter, instead of your ground wire. I guess you could use some math to determine the actual current thru the circuit. But you'd need to know a few variables, like the ammeter's resistance.
then why is the switch that is needed on a ground side. so much smaller then as on the power side ? that is why all asian car manufacures use ground switches and only power control as nessary. aslo try this take a basic cicurt measure voltage drop along the cicurt and you will find that the volts do drop. p.s. please explane if all the electrion that are in the possitive side are then in the negitive side how does the battery go dead?
“It's not really a physical thing”--- as we proved in 1977 @ Fermilab in Batavia ill electrons are a physical thing ,simple explanation= you can see, feel, touch, hear, and see the effect of a electron i.e. therefore it is physical.
Electrons are physical objects. "Current" is more of a concept, I guess.
Not sure what you want me to discover by measuring the voltage drops. But it doesn't prove your point. Current is the same thru both the power wire and ground wire. I'm not going to try to explain it here. Pick up an old electronics textbook (19th Century or newer), and read the first chapter.
A battery goes dead when all the free electrons leave the neg side and come to rest on the positive side (<-- simple explanation). When you charge a batt, you remove electrons from the positive side, and put them on the neg side.
Actually, running a ground wire directly from the battery to the amplifier is probably the best thing to do. It eliminates a Ground Loop from happening. That's not a good sign. If you care enough, you need to reroute all your grounds to the SAME GROUND POINT, and that outta be the battery, this way the battery acts as a large power filter. So the power out of the battery should be just as clean as coming from a cap.
WEll, reroute all the ground wires from your audio devices. Don't try doing it to the entire car.
i had an amp to sub, i wanted to be able to turn this off seperate from HU
i took a wire from acc to a switch to my amp this also means if you forget to switch it off your amp wont eat you battery,
check with you amp manufacturer tha remote voltage can vary for diffrent systems 5v to 12v
Audio = 100%
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