How to Boost Voltage from 1.2 (or 2.4) Volt to 12 Volt?

I want to Build a flashlight as small and bright as possible but it doesn't need to last long. I allready got a case i want to use, it has enough space to fit 2 rechargeable AA's and 2 1000mA LED'S + cooling thingy. But to build it I need at least 7-8 Volts (12 woud be better). I only need it for like 10 Minutes between recharging so I don't really care about efficiency. Every schematic and formula will be helpful :) Oh and it would be nice if it's cheap ^^

Thanks from Germany :)

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iceng6 years ago
Here is a simple Maxim part to do what you want.
Maxim will even send you 2 free samples if you log on and ask nice :-þ

A boost converter might do the job you should look them up.
iceng6 years ago
What kind of light needs 12V ??
pro2xy iceng6 years ago
Lol! Those must be interesting LEDs to play with :P
orksecurity6 years ago
Websearch "DC to DC converter". Basically, use your low voltage to run an oscillator, run that into a transformer to step up to something above 12V, then rectify, filter and regulate back down to 12V. Note that you can not get more power than the battery can supply, and in fact will get less due to inefficiencies in this process -- you can't draw more current out of the battery than it can supply, and in increasing voltage you must proportionately lose current capability (power in watts is volts times amps).

You're trying to draw 2 amps of current at 12 volts -- 24 watts -- out of a pair of AA cells. In real time, rather than doing something like a Minty Boost and drawing power over an extended time period. I'm really not convinced you're going to get there, even with lithium cells; check the discharge curves of the batteries you want to use (usually available from the manufacturer's web site).