I am trying to create a circuit that will take a 24 Vdc supply and turn it into a 12Vdc output if anybody knows how to find a schematic or mite have a schematic laying around so I can build this that would be great or if you have any input on how to get this project done. I am a very green beginner in the avenue of electronics but if you can help I would appreciate it very much.

thanks in advance
daddy

 

Depending on what it will drive (the load) it can be as simple as a voltage divider or an amplifier (attenuator) and as complicated as what's called a buck converter.

Can you reveal what it will be driving and what kind of output current will be necessary?

 

it will be driving a psp car charger I believe it is only 5 amps

 

I am a commercial diver and I dive sat so I am in a pressure chamber and ther is no plugs inside the pressure chamber but I have a 24 Vdc supply and I need to be able to plug my little voltage reducer into the power supply from the chamber and plug my psp car charger into my project here so I can charge my psp.

 

Then you will be after a battery charger circuit. There a many reference design available for free on the web. You will need to know the types of batteries your will be charging. The methods and cutoff/trickle condition vary amongst NiCd, NiMH and lead acid types. The last thing you want to do is make something that will be dangerous or fail.

 

Wouldn't it be a bad idea having electric items in a saturated atmosphere?, sparks and high pressure oxygen perhaps isn't good?.

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I have a car charger already which I believe would act as the battery charger circuit I just need to make the hard plumbed 24 vdc power supply that comes out of the wall in the chamber go into a box that reduces the voltage on the other end to 12 Vdc with a cigarette liter socket putting out 12 Vdc to plug in my car charger for the psp

 

I wonder how the PSP LCD will handle the high pressure.

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Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

we take the psp in under pressure all of the time and no problems at all I have had mine at 900 feet of sea water which is appx. 450 psi and no problems so it is pretty durable. we cant take computers in because of the sealed hdd it will crush not good!
al

 

the o2 and electronics is not really a problem atmosphere in there usually contains less than 10 percent o2

 

use this in the google search and you'll get tons of hits.

"24V 12V stepdown converter"

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L.Chung

 

If you have access, via library or local amateur radio club, to some of the 1990s and early 2000 editions of the Radio Amateur's Handbook there is a 28 vdc to 13.8 vdc converter project good for 10 or 20 amps. It's what I'll call old (but still valid, practical, useful) technology and modifying the design for reduced current is likely as simple as reducing the number of pass transistors. The project is described in detail though I would not say it's so simple anyone could do the project. In terms of performance (capacity, regulation, current limiting) I would say it's overkill but again, the article is detailed so it might be an option.

I cannot tell you if the components used are useful in the chamber. My concerns - at any significant amount of current (you'll be easily in that range) it would seem that failure modes could result in lots of smoke - maybe not fire but smoke. I don't know how well your chamber can clear something like that but I can tell you that many designs, including the one I've described, were not designed to be failure-proof or to fail in a safe (smoke free in this case) way.

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stevez