Joule Thief

[jeanna]

All JT circuits I've seen have AC. A bridge rectifier is not going to do it. Pulsed DC has both DC & AC. You'll need a filter to remove most of the AC.

Or you can simplify it by using a super or ultra cap instead of a bulb, and suddenly your measurements become easy since it becomes all about DC measurements.

Of course they would become almost zero as well. And nolonger show what the output is.
[Or is that why you said it? Were you being sarcastic?]

But it seems that you do not understand what is happening here.

In a joule thief with a secondary the pulses occur over time which is the same as ac but not sinusoidal.
At the C-E junction it is all pulsed dc.
After all there are 2 diodes if you look at the C-E as a kind of diode itself.

The last thing in the world you want to do in a joule thief is remove the pulses.
That is all there is.

jeanna

Hi guys anybody have bought a Ucap cause I'm trying to put a little charge in it and nothing is coming back 

I have not had much either.

I got 0.34v from the 0.8v passing through my earth battery.
Later, I got it up to about 0.9v at the C-E junction at the expense of my secondary staying on.
I can probably add a series inductor to the secondary and have it work, but it is quite an accomplishment to have both work at the same time... so hats off to gadget's success.

edit... oops I forgot to say I never did put that second diode there, which is why I never posted this. I have not really replicated it properly.

jeanna

[jeanna]

Hi
somebody try to connect cap to base coil ?
cap bright up led with high value of base resistor.
I think with cap we can reduce base curent.
in picture it is what I test.

Hi tysb3,
I am posting an old reply I made to test this.

It is dense with information and needs study, but it was an accurate test for what you are asking.
The results are taken from the secondary(pickup) wires.
I hope this helps you.

EDIT
oops that was testing the effect of the base cap (that is what we named this ) on the pickup secondary volts.

The next 2 pix are tables that show different ampsdraw using different caps.
btw
101= 100pF
102=1000pF
103=10000pF
104=100000pF

[xee2]

@ kooler

How to get more power.

[gadgetmall]

I was wondering, here, if since we use voltage to primarily light a CFL, ..wouldn't it be interesting to fix a twist bulb in acrylic, so that a constant thermal gradient can be held.

I'm thinking that a large component of the light emissions may be sustained by the current producing additional heat, and therefor a heat insulated CFL would produce more light if it were thermally insulated.  Perhaps this clear version would move heat transfer away from the glass tube

Just a thought.

I'm doing Just that with a spiral cfl . I will encase it in a casing of liquid lucite . I was doing this to potect the bulb from brakage but i guess it will serve insulation as well . . I'll show it when i complete the jeanna light . Mine will have a screw in connector so i can change different bulbs

Also i was Given the proper way to measute Ce  output current with the diode . Simply put a resistor across that junction say a  1 or 100 ohm resistor and then measure the current . It will be darn close !


Gadget

[jeanna]

@ kooler

How to get more power.

Xee2,
Did you wind them separately?
I am thinking about the recent winds that shared the same primary... I think kooler made one of these?

Anyway, did you ?

thank you,

jeanna