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# newbie question, running a 3.3 V LED with one 1.2 V NiMH

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#### johnlouie

##### New Member
Hi,

I have some 2n2222, 3904, 3906 transistors, 1n4001 diodes and some other parts (resistors, caps). How do I go about designing a circuit to run a 3.3 v LED (as a small flashight) ?

I've seen other circuits, but was wondering if its possible to do it with what I have already.

I guess its more a matter of how to do this, than what's the simplest way to get it done. thanks for any pointers.

John

how to get 3.3v from one 1.2v battery

Hi,

Thanx for the diagram, but I was more interested in a circuit that takes 1.2 volts and can produce 3.3volts (I've seen other circuits, but with other transistors)

And as a challenge, I wanted to learn how to do this with what I had on hand. I'll try to find my 20 yr old transistor book and go from there, or search on google.

Using that old adage, this is more a learn to fish than a quick TV dinner. My line of reasoning is that a resistor can lower the voltage, but what is the opposite circuit that allows for a higher voltage?

Could I achieve this with a 555 timer (and do other things like flash it too)? I'll try to find out if 1.2 volts can drive a 555 IC. Most circuits I've seen use a 9 volt battery- but that might be due to other reasons.

[btw, what did you use to make the diagram?]

thanks,
John

OSC and Vmultiplier

You could use an oscillator (555 or what ever). Have the output of the osc go through a voltage multiplier (just some diodes and a some caps)....

Try searching for voltage doublers on google, that might help.

I do all my diagrams all the time in Microsoft Paint. I have a very large paint file of components, and I copy them as many times as needed, and cut and paste them. I haven't found any CAD program that is any easier than this method.

A dc to dc converter will increase voltage. I believe it amplifies the voltage, inverts it, and uses an inductor to add to the voltage. There was a company that recently developed a complete dc - dc converter integrated circuit that was over 85 percent efficient. I can't remember the company, its not in the tech news anymore, I can't find the link, but here is a link w/ a tutorial on dc convertors.

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