Seeking help on decreasing voltage & current for personal project

a 3 volt regulator and a capacitor to keep it from oscillating would be enough if you are sure of the required volatges. Forget the amps part. The problems you will encounter are making sure the plug has the correct polarity when you are finished. And the regulator getting warm if the camera battery is dead and drawing a lot of power to recharge. The regulator has a tab with a hole in it you can use to attach it to a piece of metal as a heat sink. MCP1827S-3002E/AB is a good regulator choice at digi-key ECE-A1CKA100 is a good capacitor. Might want to add an off switch since the regulator will drain the battery when connected. even if camera is not plugged in. Have fun Tony

I wonder how much current the camera actually draws. The 2.5A is a maximum number, which has a safety margin and does not reflect continuous current draw.

You could use a linear regulator. But the efficiency could be pretty poor. 2/3 of the battery capacity will be 'consumed' by the regulator.

From an efficiency standpoint, a switched mode buck converter or supply would be your best bet. Somewhat more complex and a little more expensive. But efficiencies in the 90%s are possible. So the battery will last longer.

The simplest solution would be to swap your battery pack for a couple of rechargeable NiMH cells. Two Ds connected in series should do the trick.

Thanks Paul, I've spent the last couple of hours making a pack using 2 D cells.

How long should a full charged pack last? Can you explain - why 2 D cells last longer than 2 AA cells - If both produce 1.5 volts. I'm not following

Thanks Aga> Steve wrote:

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Update: I used 2 D cell batterys - I tested the output @ 3.24 volts When I connect to camera nothing happens

Any suggestions

Think of them as similar to gas tanks for your car. A larger tank contains more gas. With more gas, the car can driver farther.

Batteries contain chemicals that react to produce the voltage. If the AA and the D batteries are the same type, then they contain the same chemicals. The D is bigger, so it contains more of them, and therefore lasts longer.

Ed

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What (different) happens when you connect the appropriate 3V wall wart type supply to the camera?

If the D cells aren't working, check the polarity (compared to the wall wart). There should be a little polarity marking near the jack as well.

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Really quite simple, the D size cell carries 4 to 5 times the energy of an AA cell, thus should last 4 to 5 times as long.

same reson a 205l barrel of fuel lasts longer than a 20l jerry can