Pocket PC Power Supply

[cj_eds]

Does anyone have a PPC that has a 5v 3A power supply? If so do you also have a car adapter at the same rating?

I've been trying to get a car adapter but unfortunately they never state their current rating - usually because its a lower current. The cf-gps I use sucks too much current so drains the battery when used with a lower rated supply. When I use it in the PC cradle that has a built in 3A supply its fine however.

Any car chargers for iPaqs etc that are definitely 5V 3A I can butcher to meet my requirements! First I need to know one I can buy and know its the rating though.

[dieselnut]

I have an Axim, 5 Volts, 2 amps... if you're reasonably versed in electron hearding, how about Maplins for a voltage regulator IC or two, you'll get a fixed 5 volts, you just need a big-ish heatsync for passive cooling.

Matthew

edited to add: [url]www.maplin.co.uk/module.aspx?TabID=1&criteria=regulator&ModuleNo=7939&doy=3m6[/url]

Two of those will set you back £1.22 you just need some stripboard, a fused ciggy lighter plug, heatsink, and an ipaq cable (a standard jack plug?)

Should set you back less than a tenner including case if you're in need

Edited by dieselnut on Saturday 3rd June 00:25

[cj_eds]

dieselnut said:

I have an Axim, 5 Volts, 2 amps... if you're reasonably versed in electron hearding, how about Maplins for a voltage regulator IC or two, you'll get a fixed 5 volts, you just need a big-ish heatsync for passive cooling. Matthew edited to add: [url]www.maplin.co.uk/module.aspx?TabID=1&criteria=regulator&ModuleNo=7939&doy=3m6[/url] Two of those will set you back £1.22 you just need some stripboard, a fused ciggy lighter plug, heatsink, and an ipaq cable (a standard jack plug?) Should set you back less than a tenner including case if you're in need Edited by dieselnut on Saturday 3rd June 00:25

The maplin home made one was the first attempt, but it all ended up in smoke and burnt skin
Th emphasis should be on the big heatsink

[Zad]

Dropping 13.8V to 5V at 2A would generate (13.8-5)*2 = 17.6 Watts.

Now consider how hot your 15-20W soldering iron gets

A 2A regulator is unlikely to be able to deliver 2A at that sort of voltage drop without a really fancy heatsink. You could use a resistor or diode string to help dissipate the drop, but far better would be to use a 5A device or a bypass transistor.