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how can I get 19v from my car? Answered

I've got a old Hp e-vectra (p3-633 with about 128Mb Ram) that I'd like to convert into a car-MP3 player with some video capabilities. The input rating is 19v DC with about 3 amps. I know that the alternator outputs about 14v at normal running speed, but how can I gt the 19v I need for the pc? By the way, the current power adaptor is dead, so I can't install an inverter to upscale the voltage to 120v.
   Thanks a lot!


Laptops are made for those who like to travel. Thus car-powered laptop charger-power-supplies exist. I've seen them. I might even have one around here somewhere.  Such a device will take the power it finds at your car's cigarette lighter receptacle, be it 12, or 14, or 15 volts, or even if it varies within this range and has all kinds of electrical noise on it. It will take this somewhat ugly power and turn it into nice, clean, voltage-regulated DC, at 19 VDC, or 16 VDC, or whatever the specification might be.  They make different ones for different voltages.  Although I think seen one that does either 16 VDC or 19 VDC, by way of a little two-position switch on the case that you set to, you guessed it,  either 16 or 19.

Anyway, such things exist, and they work.  Moreover buying one would probably be a lot quicker and easier than engineering your own.  Try looking on eBay, and see if they've got one that claims it will work with your brand of laptop.  If your lucky they'll even throw in the one, special, funny-shaped connector, made just for the power port on your brand of laptop.

Websearch "DC to CD converter". You need to get a moderately high-power oscillating signal so you can put it through a transformer to step up the voltage (remember, in doing so you lose amperage, so the current has to be significantly higher on the input side), then rectify and regulate that to 19V.

Battery —► AC Inverter —►AC-in, DC-out Power supply