Joule Thief

[hazens1]

Built my first 555 timer led driver. It runs with a single 1.5v or 2. It's brighter with 2 cells. I got the circuit from Bill Marsden at this link..
http://forum.allaboutcircuits.com/showpost.php?p=117641&postcount=6

Many thanks to him..

Here are some pictures running on 2 AAs. Voltage is dropping about 0.025v every 10 minutes drawing ~50ma. LEDs are really, really bright. Blinding even at an off angle looking at them. Not sure what Henry the coil is. Does anyone know how to calculate that? Looks like the coil is about a 40-50 turn, fine wire on a bobbin ferrite core about a third of an inch tall. I followed the attached circuit almost exactly except the coil and the cap. I think my cap is ~735pf according to my DMM. I'm driving my 4.5v AAA push light circuit with it. I may package this back up into the push light and run it off 2 AAAs instead of 3. I'm going to buy some more from Wallmart. My plan is to come up with a few comparable driving cicuits with 555s ands JTs and compare to the original and see how much better my modifications are. My DMM sampling in the meter view software for the first graph was 1 sample per second and the second one sample per 10 seconds.

In the second sampling, you can see the voltage of the 2 AAs drop from 3.100v to 3.050v over about 20 minutes time.

Transistor is oscillating at a frequency of 93khz, the pulse width is 6.8 micro seconds and the pulse duty is 63.2%

My other plan is to combine a classic JT circuit with this one see what the difference is.

Enjoy

[innovation_station]

hello all

@ dog i will build you what you need sorry not to reply via pm yet ...

if you like to do it yourself is a great idea 

GUYS    WELL I WAS DOING YES ANOTHER DEMO TODAY ....... BUT NOT INVESTORS   

LETS SAY ...  IT IS A LIKED THING 

ok but the kool part is this..... im gonna do a video of it lol


EVER CHARGE A BIG CAP FROM A DEAD AA BATTERY .... AND A MK2 COIL ... LOL !?!?!?!?!?!?!?!

I DID TODAY

       

WARNING    BE CARFUL.......

im sure many remember my mot unit ......  lol   

TIME TO DO IT WITH A DEAD AA.....


IST!!

[dog812]

Hey everyone , thanks for the reply..
I just dont know enough about these to make my own design that will work.. and since i am selling these to people I want to make sure they are going to work for reliably for a long time. over and over...
.. i would be willing to buy a design from someone even.. and then make it on my own..

If you are interested please email me to discuss..
dog812 @ gmail.com

[innovation_station]

OK

i have a design for you i have built tiny ones ... 


they work a long time ......

they can lite as many leds as you like ...

ist


powed by a watch battery ... 

how many do you want ...

the finished ring mesures 3/8"

i can tune to whatever you want as an output....  as in powering leds 10 20 50 100   dont matter to me .....

[Mk1]

@ist

Take one of the mk2 toroid and make a positive feed back system , mine charged cap even faster with that system , to do so you take one coil of each side and connect them in series , test to make sure to get the best output , do the same with the second set of coils , then rectified on the negative you keep as negative for cap and the positive side of bridge you send to the not rectified coil , check again for the right phase then take the output of the coil (made for the second set of coil) And that will be the plus side to the cap. it is worth the try !

So you tried feeding the 6 mk2 with the 2 of 3.6v pack , good that was the idea for the divider in the first place that is how it was design , but the question is can you keep those in working range with the coils feedback?

Ist , even if i don't really like money promises , i am not against your kits idea , i have many , but we need a good supply of good toroid and that is the major issue i have , since they all are different we need to make sure they work all the same . Don't you think ? if we need to redesign every new shipment ?  not really good idea.

.