Joule Thief

[kooler]

T = 0 hours Initial voltage: 1130mV
T+2 hours: 1137mV
**disconnected oscilloscope and voltage meter**
T+13 hours 1124mV
T+15 hours 1128mV
My question is - is this behavior typical of a bjt or jt circuit (still new to the circuit)?  The battery is a 1.4v ni-cad rechargeable.

Thanks!

hey void109,
yes that is typical of the bjt but not the regular jt..
can you please post your other finds in the bjt thread..
http://www.overunity.com/index.php?topic=9733.msg257118#new

thanks
robbie

[resonanceman]

Hello guys,

Here is the scanned document (of the pic programmer) i promised.
I adjusted one thing tho and this is important!
The zener diode on the circuit (the 5.1 Volt) isn't a 5.1 volt but a 5.6 volt.
This is because of the diode right behind the zener it takes the voltage down and you want a voltage as close as possible to 5 volt so 5.6 volt is the closest!!!

Further the circuit is one on one.
I didn't build it as an ICSP but if you put a header where the socket is it is converted to an ICSP programmer (it's as easy as that).

If any of you guys want to see it in action look at my previous posts for the youtube link.
Enjoy.

Flux 4 Energizer

Flux 4 Energizer


This looks  similar to a project I have been thinking for a while.
My project  is a controller  to prevent  overcharging  a Ultra cap.
I was  planning on using  a LED like your circuit  uses a zenier.
Most red LEDs start conducting  at around 2 V ....... my U cap is 2.7V
I was planning  on  driving one  transistor with the LED .  Once the LED started  conducting it would   power a  transistor  that  would  be connected to different  places on the JT charger .......the places  would   be chosen  to  disable the JT circuit to some degree as the transistor  turns on......There  are many configurations of the JT circuit that will not work well........this transistor  would  just change the configuration  enough  to keep the JT from effectively charging.
My best guess for the location for  transistor is connected to an extra primary coil....... I have not tested it  on a regular JT coil but on my candy cane coils   an extra primary winding makes no difference at all as long as it is not connected to anything.   As soon as you  try to take  some  power off of  it.......the JT crashes.


gary

[Flux4Energizer]

@nievesoliveras

That is really nicely done!
Thank you for making that scematic.

@Pirate88179 / Bill
Thank you for the nice comment, but it's not that hard to understand tho.
If you like i can try to explain the circuit to you.

@teslaalset
I will do a circuit scematic a.s.a.p.
Don't have it completly myself. I just adjusted thing and fiddelt
with it till it worked and as you have seen there are a
lot of alligator clips to run through.

Regards,

Flux 4 Energizer

[Flux4Energizer]

Flux 4 Energizer


This looks  similar to a project I have been thinking for a while.
My project  is a controller  to prevent  overcharging  a Ultra cap.
I was  planning on using  a LED like your circuit  uses a zenier.
Most red LEDs start conducting  at around 2 V ....... my U cap is 2.7V
I was planning  on  driving one  transistor with the LED .  Once the LED started  conducting it would   power a  transistor  that  would  be connected to different  places on the JT charger .......the places  would   be chosen  to  disable the JT circuit to some degree as the transistor  turns on......There  are many configurations of the JT circuit that will not work well........this transistor  would  just change the configuration  enough  to keep the JT from effectively charging.
My best guess for the location for  transistor is connected to an extra primary coil....... I have not tested it  on a regular JT coil but on my candy cane coils   an extra primary winding makes no difference at all as long as it is not connected to anything.   As soon as you  try to take  some  power off of  it.......the JT crashes.


gary

@resonanceman

Hello resonanceman,
I maybe interpreter your intentions wrong, but the way
i understand you, first of al you want to use a led as an overcharge
protection for a supercap.
This can be done but i woudn't go this way and i will tell
you why not. When you feedback the energy held by the supercap the led turns on,
this works great but the led will then take (depending on the led specs) 5mA up
to 20 mA (unless you take a low current one 2 mA).
So that is all loss. I would rather go for a zener in series with 2 parallel
resistors; one going to the negative of course and one going to the base
of a transistor or mosfet. This way you can controle the voltage level of the
supercap much more accurate and you will lose a lot less current
(for really low losses you can even darlington the transistors!!!).

The second i read from your story is that when the charging from the supercap
starts the input should stop (if i understand correctly).
This can be done quit easily; just place an extra transistor or mosfet
acting like a switch.

But now for the real problem; the way i can make up out of your words your JT
works just fine, but when you put a secondary winding on and you want to tap
energy of the JT crashes and doesn't work anymore!
Well this is a problem which sounds very familiar.
I can't tell you exactly what you should do because i don't know what kind of
circuit you're using, but i can explaine.
What probably is happening is you have a JT circuit with a secondary running
some leds well this works just fine but now you take out the leds and put in
a supercap therefor the capacitive load of the circuit changes and therefor the
resonance frequenty changes, when these two are out of sync the JT doesn't do
a thing (or crashes if you like).
You will have to see a JT circuit like a RCL circuit.
I would recomment to use koolers BJT circuit and use a 4k7 or 10k potentiometer
to tweak the circuit to find resonance.

Reagards,

Flux 4 Energizer

[freepow]

  sorry Jeanna,  I meant just using only 10-25 mA draw from the battery powering hopefully 10-15 bright LED's.