12V to 5V - how do I do that then.

1,922 posts · joined Apr 2003 · 4 Mar 2006, 9:12 pm

#460958

Got a gizmo I want to run ... sept it wants 5v to run, not 12v (basically comes with one of those 240v plugs that has a 5v power output female connector).

So how to I get 12v down to 5v - with a resistor or something ---- jaycar? what gizmo.....

Cheers

Loves a lolcat

barls Administrator Causer of Chaos and Mayhem

9,473 posts · joined Jun 2004 · 5 Mar 2006, 9:15 am

#461006

a step down transformer or power regulator

“We all pay for life with death, so everything in between should be free.” Bill Hicks
the chaos project - click me

type3lover in the garage...

796 posts · joined Feb 2005 · 5 Mar 2006, 9:29 am

#461010

Dick Smith sell 3 pin voltage regulators that will do what you want. They are only rated at 1 amp so will only run a device with a small current draw.

LM 7805 CT +5V 1A V/Regulator $1.20 each

Cheers!
Toby

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crewcabconnection Being Sid James

1,922 posts · joined Apr 2003 · 5 Mar 2006, 10:57 am

#461031

cheers for that...

Loves a lolcat

tassupervee That really hurts doesnt it!

1,171 posts · joined Sep 2003 · 5 Mar 2006, 11:01 am

#461032

In the Data section of the Jaycar catalogues, you will find some really simple power supply circuits where you can use an LM7805 kind of regulator that you can bias a 2N3055 power transistor to make yourself a pretty much bulletproof and high powered regulated power supply if you need more than about 1 amp continuous.

The circuit is really basic and there are just a handful of parts needed and all the info you need to make it is in that section of the catalogue.

L8tr
E

Im not a complete idiot, quite a few parts are missing....

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 5 Mar 2006, 3:26 pm

#461103

i bought one of those DC to DC converters from cheap skate auto to run my hands free and it was the biggest pos i ever bought
its suposed to drop 12 volts to either 1.5, 3, 6, 7.5 or 9 but it to is only good for 1 amp

Joel

Quoll Officially Full-On Dubber

232 posts · joined Jan 2003 · 5 Mar 2006, 4:50 pm

#461121

I made a dc to dc conveter for a mate to run a ps2 slim line; I used a few voltage regulators in series (or was it parallel?) I think the draw was fairly large like 9 amps or something I just mounted them to a heat sink in a little kit box. From memory you could use a resistor if you know for a fact that it will only draw a consistant amount of current and that the input voltage is always the same.

firefly Slammed & Awesome Dubber

99 posts · joined Jan 2006 · 7 Mar 2006, 12:10 pm

#461644

Firstly look at the item you are wishing to run. Next work out how much current it will draw maximum. Most to the items you will be wanting to plug into such a supply will be under 2 amps. Your best bet willl be to design and build a unit to do it for you as per discussion Tassupervee has raised. this will give you a better outcome and something robust. I would also build it in such a way that you cannot plug it in backwards and thus reverse polarity it. This can be exceptionally bad. Always fuse BOTH the input for the device as well as the feed to your supply. this will protect both the unti you are plugging in and also your power supply.

If your looking at current under 1amp then a simple variable cig lighter socket type device may fit your requirements. just means that you will need to fit a cig lighter so that the supply can be plugged in. This will also give you the added bonus of plugging other 12V cig adaptors etc (like phone charger, or portible dvd into the socket).

Cheers

T

PS: What is the device you are wishing to run??