Compact and easy joule ringer needed

[human011]

I have followed some threads on ringer and have seen many variants, specially the transformer used . like aircore and stepdown transformer types .
I want to make a popular light for RURAL INDIA.Most charge lights available are of low quality or costly .
Please suggest a joule ringer built that has the following
*powered by 3V nicd cell that is easily available everywhere
*small transformer , maybe 230v to 12v step down if i could use it will be excellent.
*i dont mind core loss etc if one charge can light 11W CFL/LED bulb for 6Hours
*i can source both 2n3055 ,2n2222 The smaller one 2N2222 will be preferred
--- one CFL--- is enough, preferably low component count

*Air cores are bulky ,maybe if we canuse the 12V EI transformer it will save us from hassle of winding, these trafos are common here

Thanks in advance ,sorry i could not locate the proper schematic however i can see many videos with a compact joule ringer around 1 CFL/led bulb.

[Farmhand]

Good Idea and worthy cause

Hi human011, I think that's a good idea. I think for a Joule ringer or Joule thief
a transformer with three windings is needed, a primary, a feedback coil and a
secondary (output) coil.

Is there a common type of transformer that has these windings with a
suitable turn ratio and wire size for the required power ? That is the question I
guess.

A somewhat standardized circuit to work with some slightly different (recovered)
small transformers, and reliably enough so that a child could turn it on would be
handy.

The only problem I see is with the electrical noise they produce, some people
are "electrically sensitive" and Joule Ringer type noise can make them quite ill.
Animals can also be affected. Adults generally cannot hear in the same range
as children as well, so a device that seems silent to us might be creating an
unbearable ringing sound for children and animals. The last thing we want to
do is drive the kids and the animals mad with a constant ringing for six hours.

If we can take the "ring" out of the Joule Ringer it would be a big step
forwards I think. Shielding ect. might work. Also if they work at 20 Khz or
more would make them silent to most people.

Aside from that I like the idea.

Cheers

[human011]

Thanx Farmhand,
you are actually correct no one likes the buzzzzzz from the ringer .
The good news is the EI transformer version made by the following guy is
in khz range .So for humans it is silent, (cant guarantee about kitty/doggy, i am sure it will be last concern... )

Concept originated from admirable work by member peanutbutter .
This circuit in the video @7:33 actually fits the requirement .
Super Joule Ringer 2.0----The Amazing Peanutbutter model - YouTube

The maker has a pot to tune it, but the sad part is it is running off 12V.
The moment we tune it to take 3V , we can win.

I can get transformer of any special spec but in villages most people cant get access to custom built trafo ,also it will be tough to replace .
So i will pefer to use 230V -to -6V or 230V-to-12v transformers which are available at 0.5$ in most places.
Let me hunt for it.

[human011]

pictorial view

I have made a pic of the required circuit
Some similar circuits :
1)12V-to-120V joule ringer,uses 12v EI transformer: exists(peanut butter model)
-we want to power with 1.5 or 3V,limiting to 2 nicd batteries
2)1.5-to-120V compact joule ringer : exists (known as jeanna's light)
-we want to avoid the toroid and use 12v transformer
3)1.5V -220V using mobile 5Vboost charger exists(KAZAM Light.ASF - YouTube KAZAMs Light)
1.5V-->mobile5v charger->555 circuit->stepdown trafo reverse connected->120V LEd bulb
This one is great uses 555 timer to do PWM and you can easily tune with a 3.6V stepdown transformer reverseconnected to get the light bulb working
Video shows 50mA for pretty good amount of light .Mobile charger creates 5V to make 555 working
-problem here is slight increased cost