Led driver

This is a circuit that will drive leds brightly on 1.5v AA and the circuit will run down to 0.3v and could be used in a torch.Higher input voltages can be used but it would be advisable to use more leds.
Circuit latest- Here is an updated circuit diagram.
http://img15.imageshack.us/img15/1015/updatedleddriverwithadd.jpg

Category:

Science & Technology

Tags:

• slayer
• sec
• exciter
• joulethief
• joule
• thief
• wireless
• energy
• transfer

[therealjammit]

To help speed up the transistor switching and help start and maintain the oscillations, try paralleling the base resistor (24K in your circuit) with a non-polarized ceramic capacitor in the 10 to 20 pf range.

[jonnydavro]

Hi therealjammit.I will try it.Since i made this vid i have added a cap to the led string.I have added a link in the more info section.Cheers.Jonny.

[OnenessApostolicMan]

Did you say you use a 6KB Trigger coil? Where do I get one of those? Thanks

[jonnydavro]

@OnenessApostolicMan.You can get them from most electronics shops or from a disposable camera which has a flash.I got mine from maplins in the uk,I think mouser has them in usa but you can get a camera from anywhere and I have built one with a camera trigger coil and it works great.Check more info for latest circuit diagram.Jonny.

[medi40]

Many thanks in return for replying me. I used the same parts as you did except the transistor which was 2N2222A. I measured the current draw across the 1ohm resistor (in series with the battery positive lead). Did you get the same current consumption for the 2N2222 as well, I wonder? medi

[jonnydavro]

Hi medi40 .The 2222 works fine.Can you double check all connections,especially all diodes as something is amiss.Your current draw should be around 48mA. Have the circuit diagram handy and go through it slowly and let me know if you find anything amiss but one way or another,we will sort it.Jonny

[TriggerHappySnappy]

Hi Jonny

How many mA are you getting across those LEDs? 5mA?

I'm thinking of making a 10 LED(31V) circuit with 3x1.2V NiMH(3.6V) hopefully running at 20mA. Can i use your circuit with a higher resistor to lower the gain? Many thanks

Tan

[OnenessApostolicMan]

@jonnydavro Thanks!

[jonnydavro]

Hi WodeBolder.Sounds like you are getting some interesting results.5mA is very good for 9 leds :-) Mine self starts due to the 24k resistor.What value and transistor are you using?You could try changing the resistor value and the transistor or you could build the touch start of your circuit into a torch and eliminate the switch.Thanks for trying it out and i hope it is of some use to you.Happy experimenting.Jonny

[WodeBolder]

hey jonny.. awesome job!!! i managed to get 9 leds going on 5mA but i had to 'activate' the circuit by touching the resistor (the side connected to the base)... did yours do that?