Computer power supply shuts off when charger is plugged in?
02-12-2010, 07:35 PM
#1
Computer power supply shuts off when charger is plugged in?
So I bought a cheap PSU that's rated at 11 amps on the 12v rail, and I'm having issues powering my charger.
All I did to it was ground the turn-on wire so it turns on when I plug it into the wall, but as soon as I plug my charger into it, it shuts off and I have to unplug it and wait 5 minutes before it will turn on again. If I plug the charger into the psu and THEN plug the psu into the wall, no problems. In fact I'm charging a battery with it right now..
Anyone have any ideas why it might not like to be hotplugged? Anyone see this happen before?
All I did to it was ground the turn-on wire so it turns on when I plug it into the wall, but as soon as I plug my charger into it, it shuts off and I have to unplug it and wait 5 minutes before it will turn on again. If I plug the charger into the psu and THEN plug the psu into the wall, no problems. In fact I'm charging a battery with it right now..
Anyone have any ideas why it might not like to be hotplugged? Anyone see this happen before?
02-15-2010, 12:27 PM
#2
Tech Adept
Connect charger then turn on power supply see if that works .... PS is sensing abnormal load therfore shutting it down to prevent damge to CPU thats why it shuts down on you its doing it job !
02-16-2010, 06:58 PM
#3
Sorry if I wasnt clear, I meant to say that I DID connect the charger before turning on the psu and it DID work. But another guy who has the exact same PSU can hotplug his chargers all the time with no isues..
02-23-2010, 12:01 PM
#4
Unexpected Shutdown -- I've made the recommended changes, but when I connect my charger, the PS still shuts down. Now what?? The usage of a PC powersupply as a substitute for a field charger power source falls far outside the intent of the original design specifications. Once the PS is running and stable, the overload circuitry is tuned to detect high current sinks and shut the PS down -- under normal usage, these sinks would be indicative of an internal short in the PC. When a microcomputer is running, powersupply demands change, but these are minimal and are usually associated with optical, hard or floppy drive usage or USB devices being attached. Some field chargers produce a high current sink when first attached and generate a latch into the overload state -- as designed. The specifications state that the PS will remain latched until the load is removed from the rail -- the PS will either automatically reset or may require at least one PS_ON cycle. Even though your PS may have sufficient wattage to effectively drive the charger, the load change is the problem. One method that has been effective is to attach the charger before powering up -- to the PS, the charger now appears as a high draw motherboard and not as a potential short occurring after the PS is stable.
*EDIT* Just found out I can't post links yet.
Just do a Google search for "power supply convert" and the first couple sites should be the ones I'm referring to. *EDIT*Another problem you may run into is your charger giving errors in the middle of a charge. The 12v rail on your PSU doesn't put out quite enough voltage unless you hook up some resistors as mentioned in one of those articles.
If you are going to use a computer PSU I strongly recommend taking your time and converting it right. I tested a charger on one where I simply grounded the green wire like you did and the charger would quit partially through the charge but did eventually get it done after restarting a few times. I figured I'd take the leap and do it right. Now it works great and only cost me about $10 in parts.
Make sure you desolder or heat shrink all the extra wires in the case you aren't using. A short somewhere could melt your charger. I also installed a toggle switch and a couple banana jacks to clean up the box. My plan was eventually to strip it down and paint the case but it never happened. I wish I had a pic to post.
02-23-2010, 01:23 PM
#5
...basically what njballa said. So do like you have been and connect charger first. That's taken from this site:
*EDIT* Just found out I can't post links yet. Just do a Google search for "power supply convert" and the first couple sites should be the ones I'm referring to. *EDIT*
Another problem you may run into is your charger giving errors in the middle of a charge. The 12v rail on your PSU doesn't put out quite enough voltage unless you hook up some resistors as mentioned in one of those articles.
If you are going to use a computer PSU I strongly recommend taking your time and converting it right. I tested a charger on one where I simply grounded the green wire like you did and the charger would quit partially through the charge but did eventually get it done after restarting a few times. I figured I'd take the leap and do it right. Now it works great and only cost me about $10 in parts.
Make sure you desolder or heat shrink all the extra wires in the case you aren't using. A short somewhere could melt your charger. I also installed a toggle switch and a couple banana jacks to clean up the box. My plan was eventually to strip it down and paint the case but it never happened. I wish I had a pic to post.
*EDIT* Just found out I can't post links yet.
Just do a Google search for "power supply convert" and the first couple sites should be the ones I'm referring to. *EDIT*Another problem you may run into is your charger giving errors in the middle of a charge. The 12v rail on your PSU doesn't put out quite enough voltage unless you hook up some resistors as mentioned in one of those articles.
If you are going to use a computer PSU I strongly recommend taking your time and converting it right. I tested a charger on one where I simply grounded the green wire like you did and the charger would quit partially through the charge but did eventually get it done after restarting a few times. I figured I'd take the leap and do it right. Now it works great and only cost me about $10 in parts.
Make sure you desolder or heat shrink all the extra wires in the case you aren't using. A short somewhere could melt your charger. I also installed a toggle switch and a couple banana jacks to clean up the box. My plan was eventually to strip it down and paint the case but it never happened. I wish I had a pic to post.
03-04-2010, 11:38 AM
#7
Whoops, forgot all about this thread. In the past few weeks I have been using the psu as-is, just connecting the charger to it before plugging it in. But I will go grab a heavy duty resistor and do as suggested, see what happens. When you guys say the 'low' voltage rails.. do you mean 5 or 3.3?
03-04-2010, 11:56 AM
#8
Whoops, forgot all about this thread. In the past few weeks I have been using the psu as-is, just connecting the charger to it before plugging it in. But I will go grab a heavy duty resistor and do as suggested, see what happens. When you guys say the 'low' voltage rails.. do you mean 5 or 3.3?
03-04-2010, 11:58 AM
#9
Yes, the 5v rail.
I wish I could post links but here is a snippet from the site I went by:
I used the 2x 1 Ohm 10 Watt resistors on mine and it's worked well. When he says they generate extra heat though he ain't lying. I have them mounted to the inside of the case with a small heat sink directly on the outside of the case, with thermal paste between all and zip-tied in place. The heat sink gets up to about 120F after being on a few minutes and stays there. Honestly I can't tell you if that much resistance is needed. A single 10 Ohm 10 Watt resistor may be plenty.
Keep in mind adding the resistor will only increase your voltage which will help the charger out a bit. It won't allow you to plug the charger in while the power is on. That's a built in fail-safe that I'm not sure you can override.
I wish I could post links but here is a snippet from the site I went by:
By using two easily obtained 1 Ohm 10 Watt resistors (Radio Shack), we can wire them in series across the +5 volt (red/black) output and increase the load on our power supply with an attendant increase in output voltage on the 12 volt line. Both resistors will be running at about 65% of their rated wattage and will not be damaged by overload. However, they will get very hot -- the single 10 Ohm resistor was dumping about 2.65 watts while each of the 1 Ohm resistors will generate nearly 2.5 times that. To keep them cooled down, it is strongly suggested that both be attached to the PS case with heatsink compound to help reduce heat buildup.
On the power supplies I have tested, all produced higher voltage levels, with increases of .15 to .2 volts and total output of 11.85 to 12.06 volts.
If you are converting your PC power supply with the intention of driving a field charger, you might consider the substitution indicated above to get a little more voltage. Be mindful that the conversion comes with a tradeoff in the form of more heat. However, a little care in heatsinking your resistors should provide a reliable and long lasting source for regulated DC power.
On the power supplies I have tested, all produced higher voltage levels, with increases of .15 to .2 volts and total output of 11.85 to 12.06 volts.
If you are converting your PC power supply with the intention of driving a field charger, you might consider the substitution indicated above to get a little more voltage. Be mindful that the conversion comes with a tradeoff in the form of more heat. However, a little care in heatsinking your resistors should provide a reliable and long lasting source for regulated DC power.
Keep in mind adding the resistor will only increase your voltage which will help the charger out a bit. It won't allow you to plug the charger in while the power is on. That's a built in fail-safe that I'm not sure you can override.
03-04-2010, 01:08 PM
#10
Hmm, I was thinking maybe loading the 5v rail would reduce the 'shock' to the system and not make it shut off anymore. I got very close to 12v when I checked it with my multimeter the day I got it, and since the only thing I charge with it is a 2 cell lipo at 8.4 volts, I can't say I really care if I get 11.8v or 12v from the thing. :P
03-07-2010, 12:14 AM
#11
Ok, well thanks for the info guys. I went out and got 2 x 1ohm resistors and put them in series for 2 ohms total resistance. Since Current, I, is equal to Voltage divided by Resistance, I know I was pulling about 2.5 amps through. Since Power equals Current times Voltage, I also know that it equates to 12.5 watts, which is almost 1/10 of what the PSU's maximum power rating is. And 12.5 watts of heat is a lot. Low power soldering irons are about double that. It got burn-you hot within minutes, even with a sink on there. So I did some checking around and re-read that article linked, and it turns out that a single 10 ohm resistor will easily suffice. That equates to half an amp of current, and 2.5 watts. MUCH better. Half an amp is the absolute minimum to keep the PSU happy, and now I CAN hotplug my chargers without it shutting off. Further, the maximum temperature the case of the PSU got up to was only 100*F (room temp = 70*F roughly).
So, now I know wtf was going on, and have fixed it. Maybe this thread will prove useful to anyone who has the same problem and finds it in a search..
So, now I know wtf was going on, and have fixed it. Maybe this thread will prove useful to anyone who has the same problem and finds it in a search..
05-09-2018, 05:32 PM
#12
Reviving this ancient thread seeing my issue is similar....
I am trying to power a charger from a psu already in my computer and also am unable to hotplug the charger. Kind of killed all the hard work I did installing an xt60 panel mount and making some pretty wires.
Yes I have plenty of wattage to spare on my single 40a 12v rail for the charger and yes it works fine for the entire charge if plugged in before i start the PC. However Id really like to be able to hot plug it.
I'm thinking of trying an anti spark setup to plug in the charger so the instant load on the psu is initially less and hopefully doesn't force it to go into protection mode. Catch is it will have to come to full power fast enough that the charger doesn't display the "low dc voltage" error. Has anyone tried anything like this that can give some advice if it will work before i go out and buy more stuff for this project?
Cheers
I am trying to power a charger from a psu already in my computer and also am unable to hotplug the charger. Kind of killed all the hard work I did installing an xt60 panel mount and making some pretty wires.
Yes I have plenty of wattage to spare on my single 40a 12v rail for the charger and yes it works fine for the entire charge if plugged in before i start the PC. However Id really like to be able to hot plug it.
I'm thinking of trying an anti spark setup to plug in the charger so the instant load on the psu is initially less and hopefully doesn't force it to go into protection mode. Catch is it will have to come to full power fast enough that the charger doesn't display the "low dc voltage" error. Has anyone tried anything like this that can give some advice if it will work before i go out and buy more stuff for this project?
Cheers
05-09-2018, 08:18 PM
#13
Reviving this ancient thread seeing my issue is similar....
I am trying to power a charger from a psu already in my computer and also am unable to hotplug the charger. Kind of killed all the hard work I did installing an xt60 panel mount and making some pretty wires.
Yes I have plenty of wattage to spare on my single 40a 12v rail for the charger and yes it works fine for the entire charge if plugged in before i start the PC. However Id really like to be able to hot plug it.
I'm thinking of trying an anti spark setup to plug in the charger so the instant load on the psu is initially less and hopefully doesn't force it to go into protection mode. Catch is it will have to come to full power fast enough that the charger doesn't display the "low dc voltage" error. Has anyone tried anything like this that can give some advice if it will work before i go out and buy more stuff for this project?
Cheers
I am trying to power a charger from a psu already in my computer and also am unable to hotplug the charger. Kind of killed all the hard work I did installing an xt60 panel mount and making some pretty wires.
Yes I have plenty of wattage to spare on my single 40a 12v rail for the charger and yes it works fine for the entire charge if plugged in before i start the PC. However Id really like to be able to hot plug it.
I'm thinking of trying an anti spark setup to plug in the charger so the instant load on the psu is initially less and hopefully doesn't force it to go into protection mode. Catch is it will have to come to full power fast enough that the charger doesn't display the "low dc voltage" error. Has anyone tried anything like this that can give some advice if it will work before i go out and buy more stuff for this project?
Cheers
05-10-2018, 06:05 AM
#14
or buy a non crappy power supply.
Server grade powersupply
I'm reading this correctly, your trying to power a charger from a powersupply hooked up in your pc?
Are you trying to load the PSU from that initial charge or smooth out any spikes in voltage?
Server grade powersupply
I'm reading this correctly, your trying to power a charger from a powersupply hooked up in your pc?
Are you trying to load the PSU from that initial charge or smooth out any spikes in voltage?
05-10-2018, 02:54 PM
#15
It is a corsair RM550x. Never missed a beat. Pretty sure its just the sudden load causing it to go into protection rather than a quality issue? Also are spikes in voltage a concern? Seems pretty stable at 12v even under gaming load and the charger can take a DC input between 11-18V so I had assumed any small changes wouldn't be a concern.
By trying a heavy cap, any suggestions on which and how or a diy post to point me to? Played with resistors plenty of times but not so much with capacitors and the diy antispark plugs I've found seem to use resistors.
Thanks
Edit: I was trying to avoid buying another PSU as I charge connected to the PC usb pretty often. The PC only uses about 60w most of the time and not much more than 300w when gaming so was hoping to avoid buying another PSU and just use the extra juice the PC PSU already has. Charger is up to 200w but I will only ever use about 150w of that and I have a monitor on the AC line already so it's easy to keep an eye on.
By trying a heavy cap, any suggestions on which and how or a diy post to point me to? Played with resistors plenty of times but not so much with capacitors and the diy antispark plugs I've found seem to use resistors.
Thanks
Edit: I was trying to avoid buying another PSU as I charge connected to the PC usb pretty often. The PC only uses about 60w most of the time and not much more than 300w when gaming so was hoping to avoid buying another PSU and just use the extra juice the PC PSU already has. Charger is up to 200w but I will only ever use about 150w of that and I have a monitor on the AC line already so it's easy to keep an eye on.
Last edited by icekreme1002; 05-10-2018 at 03:05 PM.