Sign in with
Sign up | Sign in
Your question

ATX power supply powering car amp problem

Last response: in Home Audio
Share
May 19, 2012 1:19:47 PM

*I'd like to start out that this system works, but there seems to be an issue with turning it on.*
picture of my setup:


So I'm pretty sure I have all the hardware I need but I ran into a little troubling problem. I have a 15 inch subwoofer powered by a car amp and i have a ATX desktop power supply powering the amp. The problem is that when i would touch the remote wire to the power wire of the amp(to turn on the amp), the desktop power supply would just shut off. I have to turn the desktop power supply off and wait a bit before i turn it back on and repeat the process of trying to turn on the amp about 5-15 times until the amp powers on and the desktop power supply stays on.

The hardware I have running all of this is (im pretty sure this system is running at 4ohms):

1200w ATX Desktop Power Supply
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

(Ran a wire from the power check to any ground wire to make the power supply turn on automatically. Then, I took all of the 12V positive wires and merged it into one big wire (something like 4 gauge) and all of the ground wires and merged it together (4 gauge also i believe). Both the power and ground wires are run into the amp and have a little remote wire that i have dangling)

Kicker ZXS1000.1 1000w RMS @ 2ohm
http://www.sonicelectronix.com/item_43594_Kicker-ZXS100...

Kicker 15" CompVR Subwoofer
http://www.audiosavings.com/products/Website/Kicker-10V...


what actually happens when i would try to turn it on is:
1. the power supply would be on, the fan is spinning, all the power supply wires are plugged into the amp except for the remote wire.
2. i would touch the remote wire to the power wire and the red PROTECTION light on the amp would barely light up and die out
3. the computer power supply's fan would stop spinning and it'd be dead
4. turn the computer supply off, leave it off for a few seconds, then turn it back on and repeat step 1-3 for about 5-15 times
*after each try the red PROTECTION light lights up a little brighter/stays on for a little bit longer
5. Finally, the red protection light will stay on for about 3 secs, then the amp would turn on.



Now I have no idea how to fix this but i think the amp just draws so much power that the power supply just cuts out from surge protection or some sort of protection. Eventually the capacitors in the amp/power supply would be powered enough to stay on and turn the whole system on.

i THINK this is how it would be solved:
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Sup...
on step 11 and 12, it points out that i should run a 330ohm resistor from a grey/brown wire(the "power good"/"power ok") to the 12V positive wire that goes into the amp.

Do you guys think this will fix the problem?
May 19, 2012 3:07:28 PM

I can see a few problems in this, but...the 1200W power supply is rated, to combine +12 V, - 12V, 5V, 3.2V, etc...for a total max of 1200 watts...all added together. It does not supply 1200W to the 12 V rail. Therefore, you may not really have enough to turn the amp on in the first place. What is the voltage reading on the 12 volt wires, with the amp ON? I'm guessing, 8.2 volts?

There may be a problem in the power amp also. A bad component may be tripping the protect circuit OR

You have the wiring mixed up...?
m
0
l
May 19, 2012 5:23:46 PM

it was 12.1v on the power line so its right. i mean the setup works as i said. im just trying to see if theres a way to bypass the whole try to turn it on over and over for bout 10 mins
m
0
l
Related resources
May 29, 2012 2:04:51 AM

bumpety bump bump
m
0
l
December 7, 2012 12:11:23 PM

Did you manage to resolve this issue?

I am currently having the same problem. I am using 2 x 700w 38A on the 12V+ rail Power Supply Units. They are powering(Or attempting to power) a bridged 2 channel amp rated at 1200w Peak Power (So more like 300WRMS). This means there should be more than enough power.

The amp is working fine as I have tested it in the car. The power supply unit wiring is okay as it works fine with a different 4 Channel Amp.

But together, it keeps dying. I have tried to use a capacitor but I get nothing then.

Any Ideas?
m
0
l
February 3, 2013 7:36:21 AM

did you apply a dummy load to the powersupply. ive seen tutorials where they ad a power resistor inside the unit to avoid the protection light. i think it is because the powersupply is being overloaded to turn on instead of a resistive response from the amp/ normally the computer.
m
0
l
August 19, 2013 12:29:47 PM

ITS BECAUSE YOU MUST HAVE THE JUMPER WIRE FROM THE POSITIVE TO THE REMOTE ALLWAYS CONNECTED. PLACE THE JUMPER FROM POSITIVE TO REMOTE TERMINALS WHILE ALL THE POWER IS OFF AND COMPLETELLY DISCONECTED. THEN CONNECT THE WIRES AND SWITCH ON THE POWER, THE PSU AND THE AMP WILL BOTH TURN ON AT THE SAME TIME. WHEN YOU SWITCH THE PSU OFF THE AMP ALSO TURNS OFF. DO NOT KEEP THE REM WIRE DISCONNECTED AND MAUALY TOUCH IT THATS WHATS MESSING IT ALL UP. IN A CAR THE REMOTE WIRE IS FROM THE HEADUNIT TO THE AMP AND ALWAYS CONNECTED, THINK ABOUT THAT FOR A SECOND, YOURS MUST ALSO BE THE SAME WAY ALWAYS CONNECTED AND YOU ARENT DOING IT LIKE THAT.
m
0
l
September 29, 2013 10:16:11 AM

Hello
I'm having the same problem exactly like you have.. Here my video on youtube about it:
http://www.youtube.com/watch?v=aUxhNO9shRo&hd=1

I have also find another problem

I have hooked up a USB poort on my 5Voltage of my PSU (red wires) so I can charge my phone.
So this works perfect my phone is charging. Only once I disconnect my phone from the USB the fan stops working and the PSU turns off.

Very strange. Did you manage to solve the problem yet?
m
0
l
October 27, 2013 12:25:34 PM

Both of the 12v rail shut off problems, the car audio amp load shutoff when connected and the PSU shut-off when the 5v phone charge load is disconnected maybe related to the PSU you are using. I am having a similar problem when I use the 12v rails to power 12v tungsten under cupboard lights to light my Kitchen counter top. The lights are 12 v 20 w and run at 1.67amps each. I have 6 of them powered so they need 10 amps total to run. Per LT SPICE model of the 20w lamp, the lamp has an inrush current of about 27 amps each at start up, which quickly drops logarithmically to 1.67 amps with in about 1 sec.
I found this possible solution at http://reprap.org/wiki/PCPowerSupply#Troubleshooting

Electronics prepared for PC Power Supplies
Base Load
12V halogen as 5V base load.jpeg

Many PC PSUs (not all) require a base load on the 5V rail to work properly. Connecting an old CD drive or a 12V light bulb (into the 5V rail, see picture) are well proven methods to get this load.

Wether you need a base load or not has to be tried. If even tiny loads on the 12V rail cause the PSU to turn off, a base load is required. Also, a base load never hurts.

Here is some additional discussion on the arduino boards.
http://forum.arduino.cc/index.php?topic=113338.0

PS Update: I hooked 20 w 12v lamp to 12 v rail without the 5v rail load. The lamp briefly lit and the power supply shut off. I reset it by turning the power switch Off (o), disconnecting the black to green jumper (Power turn on). I then hooked up another 20w 12v lamp to the 5v rail red to black, turned the PSU switch back on ( I ) and the lamp on the 12 v line stayed on. It is still lit now after about 10 minutes. SO that must have been the problem. No 5v Base load. I do not know what the minimum base load is to keep the PSU regulating. If any one knows please comment. BTW running an ALTEC BP500U 500 watt PSU.

Here is a little more info about 5v and 12v rail loads for proper operation of the ATX PSU.
http://www.epanorama.net/links/psu_computer.html

Using PC power supply as general laboratory power supply

Many people seem to have nowadays many old PC power supplies from old comouter aroudn them and seem to want to use them for some other applications. The PC power supplies supplies many voltages (+-12V, +5V etc.), but using those power supplies successfully takes some knowledge. The PC power supplies are generally switched mode power supplies that do not like run without a load (power supplies usually automatically shut down themselves then they see no load). The AT standard power supplies do not have any special signalto stay on. They are designed to work on certain power loadsrange correctly. If they are loaded less or more than they are designed to work they will shut down themselves. Generally you need to load the +5V output enough (usually 1 amprere to many ampreres minumum load needed depending onpower supply unit, youy might need to test this).The motherboard or old hard disk connected to power supplytakes at leas this minimum load, so keep the power supplyhappy. If you do not want such devices near you, you need to have some other type of load you can use, for examplewell cooled power resistor to +5V output or a 12V car headline bulb connected to +5V output (12V bulb willglow red/yellow when powered with +5V and take enough powerto guarantee that minimum needed load). The minimum load on +5V is needed, because PC power suppliesare generally regulated at +5V output. The controllign loopon the switching power supply works well on normal load conditions, but in case of too little load causes generally the+5V output to rise to too migh voltage, which leads to theshutdown of the power supply when it detect the overvoltage. Whatever power supply you want to use the best approach is tocheck the PSU spec: some require a minimum current draw on some rails. It is quite easy to provide this by means of a power resistor or power resistors. What is said above is usually valid for most other computer power supplies as well.All modern PC power supplies are nowadays built to match the newer ATX standard. Those power supplies have more signals on their connector for example for turning them on and off. If you plan to use this kind of power supply, you need to take care of the minimum load details told above. In addition to this you need to find out the details how you are supposed to turn this kind of power supply on. To activate ATX power supply, only PS_ON is needed. PS_ON can be activated by connecting ATX power output pin 14 (PS_ON) to pint 15 (ground). Some ATX PSUs also require a load on the main +5V to start (could be even damaged without enough load). Most but not all require a load on +5V to regualte properly, a few require aload on +12 as well. PWR_OK signal has nothing to do on ther controlling of ATX power supply operation. PWR_OK is an output from the supply. "PWR_OK is a "power good" signal. It should be asserted high by the power supply toindicate that the +12 VDC, +5VDC, and +3.3VDC outputs are above the undervoltage thresholds.
m
0
l
November 10, 2013 2:01:16 PM

your problem is simply this:

whenever you touch the remote shut off wire to the positive terminal on your amp, you automatically activate the protection circuit on your amplifier, it will never work. What you need to do to fix this is find a wire (usually your best bet is the power antenna wire, this is on every single aftermarket in dash stereo wire harness to provide the functional option of maintaining your power antenna's functionality with the car, also it is only activated when you turn the key in your car to acc or on.) and run a similar gauge wire from that back to the remote terminal in your amplifier. You will no longer trip the protection circuit on your amplifier, and everything should function properly. The reason is a remote terminal is the secondary power source required to turn on an amplifier, if you stupidly and I mean stupidly run a jumper from the remote terminal on your amp to the hot positive, your amp will never shut off and eventually drain your cars battery, and even worse if you have a cheap amplifier like boss or pyle, which are not cea 2006 compliant, I have seen the terminals with a jumper ran from the remote to positive actually melt, and even cause damage to components. Remote stands for remote shut off and it should be connected to a power source in the car that only activates with the ignition of the car (That is why I say to use the power antenna wire because it is easy to locate, typically it is blue with white stripes or vice versa. You could use something else but you would have to open the interior fuse panel and find a wire that only activates with ignition of the car). Regardless of the power source you use it will still pull power from the cars electrical system, and when the car is off and there is no alternator going to give it a charge, you eventually get dead cells in your battery. The only way around this which makes absolutely no sense is to run the remote wire to a hot power source and install a toggle switch, but you would have to remember to flip it every single time you get in and out of your car, when if you just did what i told you, I am sure you have some 16 gauge wire laying around, along with electrical tape, and maybe if you know what your doing a soldering iron and solder, you could simply pull the head unti from the dash, find the power antenna wire, solder (or tape) a wire to it, pull it through the bottom of your dash, tuck it under the carpet (avoiding the rca side unless you like ground loop noise) and hook it into the remote terminal of the amp SIMPLE. Trust me, I cannot begin to tell you how many people I see make this stupid mistake. Read your amplifier instruction manual before installing any amplifier into your car. Good luck! ;)  Also, why would you use a pc power supply to power an amplifier, when a 4 gauge amp kit with a fuse able link, costs around 25 dollars at the right online retailer, and pulling a 4 gauge wire through the rubber gasket in the firewall and tucking in under the carpet and hooking that into an amplifier then grounding, ect., just sounds like a lot less work than all that power supply bs your talking about... Just my opinion though, I don't mean to be a d**k or anything, just curious.
m
0
l
April 21, 2014 6:01:50 AM

To resolve this turn on issue with multiple remote connections, use a basic relay switch the same square plug in relay they use for car alarm systems. There are tutorials all over the net as well as YouTube! This will definitely resolve your remote turn on issue! Good luck and hope you get this done

m
0
l
!