You could try a CarNetix P1260 in front of your PW-200
Can you run Regulator IC's in parellel. I found some IC's that are 12v at 5amp and I want to run a few of them to get 15 - 20amp output. I'm currently having a problem with my PW-200-M power supply because the system works great when the car is off but when I start it the power supply shuts down because the voltage goes up to 14.6volts. If i put a few diodes in line I can drop the voltage down to 13 and the computer runs great when the car is running but when I turn the car off the voltage drops down to 11 and my hard drive spins down and the system goes down hill fast. I need to way to maintain 12volts continuously to my PW-200-M. I want to avoid buying bulky external power supplies. I want the whole power assembly to fit in my double din case with the full size hard drive and EPIA M10000 main board.
You're confused. I run my Epia 10000 with a Morex 120 and a Carnetix as the regulator. As far as 18+ volts, I don't know what you're talking about. The 1260 puts out a regulated 12 volts and survives crank.
Mike runs Carnetix, he can answer your questions in more detail but if you're just trying to run a M10000 and a full sized hard drive, you'll do fine with a 1260.
Also, to your question, I believe that running linear regulators in parallel to power large circuits requires a voltage balancing circuit of one type or another as one regulator is sure to have less resistance than another and will overheat as a result.
I was looking at the wrong Carnetix. The one I was looking at was the 140 watt guy. Looks like the 1260 does output the 12v but only up to 60 watts which is not enough to run my Epia, Full size HDD, CD burner and 2 USB hubs with lots of peripherals. Thanks for the info on the regulator. I'm thinking with all the hassel I might be better off with an inverter and a shutdown controller with a relay activator for the Inverter.
What IC's were you looking at?Originally Posted by Deadnick
You can in theory paralled them, but the parts either need to have built it load sharing or you need to put together your own subsystem for that. Switching regulators can be synchronized for that purpose.
If you don't do something about load sharing, you will most likely have a shorter than expected life expectancy of the parts.
I have found you an argument; I am not obliged to find you an understanding.
You probably don't need to parallel them. Get a 12v and 5v regulator, and use those to power the HD and CDROM. in other words, connect the 12v and 5v outputs to the HD and CDROM only, but keep all the grounds connected to the rest of the computer and you will be fine (I have powered a CDROM off a separate supply many times when I brought it in to work on it on my bench and it refused to work properly with the added power consumption of the CDROM) The epia itself shouldnt' be drawing a ton of current... mine is under 2 amps I think. As for the USB peripherals... well, you can leave them motherboard-powered, if one 12v regulator is enough... or you can power them with a separate 5v regulator. My guess is that if you remove the load of the CDROM and HD from the motherboard's power supply then you should be able to handle it with a single 5A reg to the mobo. Someone can correct me if i'm wrong, but USB 2.0 is supposed to be a max of 500mA per port, so even if you use the 2 ports on the mobo and the 2 on a header, you are still only at about 2A for the USB devices... ie - 10 watts.
I would say try it out! Try it first without the USB devices, and make sure the comp can function OK with just a single 5A reg powering it. Then add the USB devices and make sure it can still function. If it doesn't, then you could get a 5V reg and power the USB devices separately (or use an externally powered hub instead of bus-powered)
make sure the 12v regulators you are looking at behave properly when the input voltage is low. Some regulators don't behave like you'd expect when the input voltage is not greater than the desired output voltage + dropout voltage. (ie - if a regulator has a 1v dropout voltage, and 12v output, then if the input voltage falls below 13v, it may have an output of slightly less than 12v, or it may be far less, depending on the device)
I'm not trying to sound like a commercial for Carnetix, but if the 1260 won't work, try the 1290. It puts out 90 watts. If you need more than that, go with an Opus for 150 watts.Originally Posted by Deadnick
Okay I made a decision. I need an inverter in my car to run other peripherals so I figure why not just have it run the computer also. I have a 1500 watt (3000 peak) inverter with a noload draw of <400ma so it wont drain my battery leaving it on for a few days. Now I can run my CarPC and survive a crank no problem. The inverter only cost me $80 US at Costco and does a fantastic job. Not only does it survive a crank but last night I ran a shop light and my CarPC off it for 7 hours while I was working in the car and my battery voltage only dropped .2volts in that time so this thing is rediculously efficient. I'm not so sure that the DC-DC stuff is that much more efficent and if it is I really don't need to be that efficient because right now I beleive my CarPC will run for 24+ hours without draining my battery. Anyways thanks for all the help guys but I decided that the inverter is definatly the way to go. As for noise in the video and audio there is not a trace. My old inverter had a little bit of noise in the line but this one handles it way better. Now I just have to buy a stereo amp so I dont have to use head phones with my CarPC