Can someone explain how a joule ringer and joule thief works?

[rushi95]

Hi Brad,

It seems the capacitive coupling is creating an unnecessary amp draw. Any way to avoid that?

I am just wondering what happens at the primary side in a basic JT schematic during the inductive kickback phase? Is the inductive kickback reflected to the primary also?

Rushi

[tinman]

Hi Brad,





Rushi

I am just wondering what happens at the primary side in a basic JT schematic during the inductive kickback phase? Is the inductive kickback reflected to the primary also?

Ok,not sure what you mean there,as you have !primary side! twice.
Perhaps you meant-what happens to L2 (secondary coil) during the inductive kickback cycle.

If so,then as i stated in my first JT post,L2 also inverts,and pulls the transistor off cleanly.

If you place two small LEDs across the 1k resistor as shown in the pic below,and a good 1.5v battery,both LEDs will light up when the JT is running.
This shows you that the L2 coil dose invert during the inductive kickback part of the cycle.

You now have a JT that runs 3 LEDs. 

It seems the capacitive coupling is creating an unnecessary amp draw. Any way to avoid that?

Nine times out of ten,you have a bulb in there,and so the capacitive coupling dose not play much of a part-as with all bifi transformers.
In some cases,the capacitive coupling is needed,as some bulbs will not allow current to flow in both directions--E.G ,LEDs.


Brad

[sm0ky2]

If you want to get fancy, you can wrap a 3rd coil around the toroid
and draw power for a secondary device


https://youtu.be/h9RgjAgSQOg


But whatever you do, do NOT put 2 forward facing diodes
into a capacitor!
No matter the size, it Will explode

[Belfior]

If you want to get fancy, you can wrap a 3rd coil around the toroid
and draw power for a secondary device


https://youtu.be/h9RgjAgSQOg


But whatever you do, do NOT put 2 forward facing diodes
into a capacitor!
No matter the size, it Will explode

Hmm what if you use a spark gap to get the extra energy out?

[rushi95]

you can use pretty much any low voltage source
here is one I did with an "earth battery"

Hi Smoky,

Since last 2-3 days I have been studying about earth batteries, air batteries, water batteries, crystal cells, etc and I do not see any potential in lighting up the bulbs better than AA batteries. Let me know if I am wrong.

What I am looking for is a cheap solution (under 20$ and even less) to light bulbs in homes of poor people. I want to avoid solar panels and big batteries because the cost increases. Joule ringer seemed a good option. What I think is 10-15 minutes of human power would be capable of lighting bulbs for 3-4 hours.

It would be interesting if earth batteries were capable of doing that.