Need advise for a Joule Thief with 20ma 1,2v power source

[ikram85]

Hi everyone!

Normally I come here to learn and make cool projects, but today I need to ask some help. We need to make a led glow, I suggested using a Joule thief but we only have a few components to make it and not much knowledge to make it.
it's giving us 1.2v aprox and 15/30ma aprox, one made with a small toroid works quite well but we need to make one without it.

we have 2N2222a
2N3904
and BC557 transistors
some caps
resistors
two types of inductor 47mH and 470mH
small 3.3v smd Leds

We need to make it small and simple and brigther as possible, any ideas to assemble it? tell me if we need to change some components
thank you for reading me

[mscoffman]

   
Here is a reference to the start of a string of posts about toroid-free JT's on here.
You will have to find a reference pathway for yourself;


---

hi everyone,

I have just uploaded a youtube video of my recent discovery-  Powerful toroidless joule thief
http://www.youtube.com/watch?v=QP8PkgT1T9o

This is the 4th version of my toroidless joule thief circuit as there are other types shown in my youtube channel :sanjev21 which is not using toroid and yet able to light led brightly.This is the final version.

Without the use of  any toroids would take the overall cost building a joule thief circuit to a new low.Here i am talking about avoid buying toroids which cost money unless you got some spares from salvage after which you still need to wind the coils.

The  Powerful toroidless joule thief  circuit can be assembled in less than 5minutes on a breadboard once you got the components ready.

The schematic is revealed in the video.

Component list
2222 transistor
4.7 kohms resistor
10nf capacitor
100uH x 2 inductor
Led

[ikram85]

Thank you very much mscoffman! i'll check that out

[Pirate88179]

Here is another one:

https://www.youtube.com/watch?v=KFswGMJ7QiI


You can make one with an air coil but it needs a lot more turns...like around 1,000 depending upon the other components.

Here is one with an air core:

https://www.youtube.com/watch?v=wNxfsS_2PVU

Bill

[Groundloop]

Hi,

The attached oscillator can be built with SMD components. The two coils does
not need any coupling between them at all. The coils can be separated in distance.
The resistor is there to give the transistor a small voltage bias so that the oscillator starts
and can be from 100K and up to 1M, 1 mega Ohm is typical used here.

Much of the oscillator frequency is determined by the value of the coil and capacitor at
the base of the transistor. 1 to 100 nano Farad will work OK for a LED driver. You can use
almost any type of LED on the output. Good luck with your project.

GL.