Joule Thief

[Mk1]

@stprue

its hard to say how many you should be able to put on , but you could very well have over 70 turns , i usually have a single cross over .

also i suggest putting both side on first going one way that will make sure you have the same number on each side, only the go down.


Edit its about 80 inch of wire on each side.

[jeanna]

Hi everyone,
I guess the new server went on pretty easily? I just thought I would try and here we all are.

Dog812,
I think there is something hooked up wrong. I do not believe that you should have the effects you are having.
Just to be sure are you using all new parts?
I think there is something wrong. Lets try to work this out.

stprue,
Beautiful toroid.
MK1 is the expert here. You are in the right hands.

@All,
I made some tests today relating the number of turns frequency and volts. There is no surprise, but confirmation. more turns higher volts lower frequency.

I had to stop in the middle to recharge my scope batteries. I am looking for the right adapter... this is too often.

I gave you the results. Now, I am going to try to add the table I made and see if this forum format will accept it. So, if there is something weird below, just don't worry, I am playing. If it looks like a table then cool.

jeanna

[jeanna]

@All,

As you can see the table is not from the forum table function. Oh well. The screen shot is easier anyway.

All these data mean to me that the next step for me is to get as many turns as possible to get the voltage as crazy high as possible then crank up the base resistor value to get the highest frequency possible and still maintain 110 or 170 volts.

I read in a search that 170 is the peak to peak we get in the states to give us a rms of 120 volts which is what the electric company claims we get, so this may be the reason my led string didn't light when I had 110 volts on a pick up.

jeanna

[dog812]

Dog812,
I think there is something hooked up wrong. I do not believe that you should have the effects you are having.
Just to be sure are you using all new parts?
I think there is something wrong. Lets try to work this out.
jeanna

All new parts yes..
3904, 3/4" torrid, 30 mag wire for secondary, 22 awg white for the primary.. 68 ohm resistor.. 3 x 5mm white LED's
I made the torrid using gadagets method of a single wire , wrap 6 times, leave a inch excess, then wrap the last 6 times.With the inch excess being where you hoop the battery positive.

What could be wrong? And why do you think there is something wrong? Just how fast it is dieing?

[TheNOP]

@Mk1

I forgot to ask you, I have realized the you can make a single crossover or a double when re-winding bak down.  How are yours done because the one you see in the pic's I just put up has both a single on one side and a double on the other.  I ask because even though it can light an led on either side, one of the side is pretty dim.  Do you know what's happening?

on one side you are changing the base's coil impedence.
on the other side you are changing the collecter's coil impedence.
since it is the base's coil that make the transistor oscillate it affect the frequency more then when you change the collecter's coil impedence.
but that is just the short explanation.

what is happening to the base coil is defined by Lenz's law.
a currents passing in a wire create a mag field that induce a currents in any near wires(or in a core).
that currents created by a mag field, if allowed to circulate, will create a mag field that will oppose the mag field creating that currents.

that is the reason i do not talk about coil's resistance but about coil's impedence.
both are a "resistance", but not the same kind of resistance.