4 x 5mm LED's off one D cell?

4 x 5mm LED\'s off one D cell?

I want to run 4 20mA blue LED's off one D cell using a boost circuit.

I figure that if products like the ARC AAA can run 1 LED off 1 AAA cell with decent runtime then what I want to do with 4 LED's and a cell with 14x the capacity should be OK.

Is my reasoning sound or have I forgotten something?

Streak

Re: 4 x 5mm LED\'s off one D cell?

Why stop at 4? /ubbthreads/images/graemlins/grin.gif

Re: 4 x 5mm LED\'s off one D cell?

You will have no trouble running off a D. That's only 80ma...a D battery is good for at least a few amps.

Re: 4 x 5mm LED\'s off one D cell?

a d is approimately 3-4 amp hours...

might i suggest a linverter or similar?

neg

Re: 4 x 5mm LED\'s off one D cell?

an alkaline d is 18ah iirc.
[ QUOTE ]
Neg2LED said:
a d is approimately 3-4 amp hours...

might i suggest a linverter or similar?

neg

[/ QUOTE ]

Re: 4 x 5mm LED\'s off one D cell?

WHHHHAAA?????????? omfg.........

neg

Re: 4 x 5mm LED\'s off one D cell?

Yes an alakline D is 18000maH and a AAA is about 1200maH.

Re: 4 x 5mm LED\'s off one D cell?

yeah... on the energizer site it says 18,000mAh http://data.energizer.com/batteryinfo/product_offerings/alkaline/energizer/alkaline_consumeroem.htm

Neg...I think you are thinking of a rechargeable D cell /ubbthreads/images/graemlins/smile.gif

Re: 4 x 5mm LED\'s off one D cell?

I thought aa had about 2500 mAH
and I think ( not sure )
that the internal cell resistance on a d battery is higher
and the 15 to 18 am hour spec for a d cell is based on a really low current drain spec.

Re: 4 x 5mm LED\'s off one D cell?

[ QUOTE ]
markdi said:
and the 15 to 18 am hour spec for a d cell is based on a really low current drain spec.

[/ QUOTE ]

It is, but it still has significantly more than 3-4 amp hours even under high drain. The 4 LEDs the original poster is talking about is an extremely low drain, so it will run for quite some time.

Re: 4 x 5mm LED\'s off one D cell?

battery charger said

It is, but it still has significantly more than 3-4 amp hours even under high drain. The 4 LEDs the original poster is talking about is an extremely low drain, so it will run for quite some time


How do you do the quote box ?


very true It will run for quite a while

MD.

Re: 4 x 5mm LED\'s off one D cell?

[ QUOTE ]
Streak said:
I want to run 4 20mA blue LED's off one D cell using a boost circuit.

I figure that if products like the ARC AAA can run 1 LED off 1 AAA cell with decent runtime then what I want to do with 4 LED's and a cell with 14x the capacity should be OK.

Is my reasoning sound or have I forgotten something?

Streak

[/ QUOTE ]
The relative capacity between the AAA and D cells depends a bit on current drain but your 14X sounds reasonable. For your application, the convertor board out of a Dorcy 1AAA LED light would be excellent. It would drive the 4 LEDs in parallel at around 20mA each.

Re: 4 x 5mm LED\'s off one D cell?

Ummm your leaving out one thing. The AAA runs off of one cell, with one LED, but it has a boost circuit. The D cell has way more capacity, but it has the same voltage as the AAA.

I would higly recommend a boost for a single cell with 5mms.

Alkaline D cells should have about 18 amp hours. I have seen D cell rechargeables as high as 11 amp hours.