Confused about DC-DC PSU for laptop

**Donny Bahama** · 09-18-2006, 07:14 PM

All the DC-DC supplies in the online store seem to be designed for connection to a motherboard (i.e. 12V and 5V outputs) but if I'm using a laptop (which wants a 19.5VDC 3A supply) and I want to replace the PSU brick and power the laptop via the car's 12V system, is there something commercially available? Or do people typically build these themselves using Radio Shack parts? I'm comfortable soldering/assembling something like this, given a schematic and a component list, but I don't have the electronics knowledge to design it.

This seems like a super-basic question. I searched for the answer but didn't find it. If there's a good thread on this topic, please point me to it.

**fixerofallthing** · 09-18-2006, 07:29 PM

http://store.mp3car.com/ProductDetai...Code=PWR%2D010

**Donny Bahama** · 09-18-2006, 07:36 PM

Thanks.

OK, now that I've seen the price on that (ouch!) is there a DIY link somewhere?

**DarquePervert** · 09-18-2006, 09:25 PM

Ouch?
My DSATX (made to use with an ATX motherboard) was twice the cost that Carnetix.

This hobby ain't cheap.

**Donny Bahama** · 09-19-2006, 03:04 PM

Expensive is relative... my wife is disabled and we're struggling to get by on my income. This hobby can be cheap; I have an old laptop sitting around doing nothing. I also have an old Pocket PC with built in Wi-Fi. I can't afford a touchscreen LCD, but I can use NetRemote to control the laptop via Girder (I have licenses for both) with RoadRunner as the front end and my only cost is the power supply. If I can get that done cheaply, I can probably scrape up the money to do this.

**Rob Withey** · 09-19-2006, 03:10 PM

Just get a laptop car adapter from ebay.
Forum rules preventing me from posting a link, but they are easy to find.

**Donny Bahama** · 09-19-2006, 07:25 PM

Thanks, Rob!

**geeky_hawkes** · 09-23-2006, 03:00 PM

Caution though, i brought one from ebay finally got round to using it (my laptop also want 19v and 3amp) and the bloody thing started smoking! It also stopped providing dc power. I checked the input and it was below the ampage stated as max input, likewise the draw from the laptop was below the max output.

As said there are cheap ones on ebay, but might be worth spending the extra few $$ over the most basic of items on flebay!

**DarquePervert** · 09-23-2006, 03:07 PM

Originally Posted by Rob Withey

Forum rules preventing me from posting a link, but they are easy to find.

Post your link. Nobody's going to smack you down for pointing a member to a seller of laptop car adapters.

**gameboy** · 09-24-2006, 01:14 AM

what is the voltage on your laptop battery

i've been able to do this with three(3) different laptops, all different brands:
1. goto raido shack and get a adapter that fits in the laptop where your ac brick would plug in
2. goto wallmart and by something cheap that has a cig lighter plug on it(or just buy it at rag shack also)

3. connect the 2 above together, and plug in your laptop that way.

most laptops have a 9v batter, and take a 19v supply to put a full charge on them. 12-14 volts will not harm them in most cases

DISCLAMER: TRY THIS AT YOUR OWN RISK, I ASSUME NO RESPONSIBLITY FOR ANYTHING THAT MAY GET DAMAGED.