# Stepping up 2.4V into 3.4V

Discussion in 'The Projects Forum' started by frustratednoob, Dec 21, 2012.

1. ### frustratednoob Thread Starter New Member

Dec 21, 2012
3
0
Hey guys, this will be my first time posting in this forum.
I was just wondering how do you step-up/boost a circuit from 2.4V to 3.4V using a boost converter?
I was searching for that schematic online, but I have found many designs that are somewhat different.

*I'm using 2 x 1.2V AA NiMH Rechargeable Batteries, with a total current of 4600mAh, or 2300mAh each.

2. ### t06afre AAC Fanatic!

May 11, 2009
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How much current do you need? That is also important to know in order to help you

3. ### Audioguru Expert

Dec 20, 2007
10,896
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No.
With two cells in series you get 2.4V at 2300mAh.
2300mAh is not the total current, it is the time duration of a certain current which might be 2.3A for 1 hour. The total current might be 12A for a few minutes.

4. ### ScottWang Moderator

Aug 23, 2012
6,588
1,021
If you use 1.2V x 3 then you will get 3.6V/2.3A.
If you use boost converter may like this:
W_in = 2.4V x 2.3A = 5.52W
Assuming transfer effiency is 80%
Iout = 5.52W/3.4V = 1.623A
If you use pwm then the output current could be Iout_pwm = 1.623A / 2 = 0.812A

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