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

[johnlouie]

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

 

[hamfiles]

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http://www.geocities.com/hamfiles/Light.htm

 

[johnlouie]

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

 

[Prof.Insane]

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.

 

[hamfiles]

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.

**broken link removed**