Joule Thief

[jeanna]

Hi
I was just editing my post and I see this about dc

The pulsed dc is not the same as dc from a battery. We know this.

I think we need to be consistent, here, Tesla made the distinction between
"steady" dc and
pulsed dc

these were the BIG differences; and when he referred to the pulses he put them into the same category as AC. At least he did in the lectures I have been reading from 1892.

3 pm lunch time!

jeanna

[resonanceman]

If  I am  right  about the  rotation   thing .......some of the people here might have the  right kind  of coil for the job.

I didn't  make a coil  gun .......but I know some of you did .
What are the  coils for a coil gun like >
Could    a similar  coil be made  for the  collector  coil  of a JT ?
It seems to me that they would  give a pretty  good kick.


gary

[Mk1]

@all

I must stress this a bit concerning the mk4 tesla toy , the use of the coil and transistor .

First the coil are each 12 turns , the drawing is not exact for turns but is for winding direction .

OK now the transistor one is pnp and the other is npn , now i tell you this because the first time i did not use the regular 2222 or 3904 i made a jt that did not work unless i reversed the battery poles , so the negative is the common to both jt coil . That way i found it easy to have 2 jt one pulling from ground and the other from the plus pole .

And this is how i build it ,worked right away that was my third jt so the pickup coil can be improved quite a bit  base resistor value also ...

[resonanceman]

Hi
I was just editing my post and I see this about dc

The pulsed dc is not the same as dc from a battery. We know this.

I think we need to be consistent, here, Tesla made the distinction between
"steady" dc and
pulsed dc

these were the BIG differences; and when he referred to the pulses he put them into the same category as AC. At least he did in the lectures I have been reading from 1892.

3 pm lunch time!

jeanna

Jeanna

I agree 

Pulsed  DC is  very similar to AC

Pulsed  DC  can  have  a rate  of change  that is  similar to AC
Pure  DC  has no rate  of change ..

gary

[resonanceman]

@all

I must stress this a bit concerning the mk4 tesla toy , the use of the coil and transistor .

First the coil are each 12 turns , the drawing is not exact for turns but is for winding direction .

OK now the transistor one is pnp and the other is npn , now i tell you this because the first time i did not use the regular 2222 or 3904 i made a jt that did not work unless i reversed the battery poles , so the negative is the common to both jt coil . That way i found it easy to have 2 jt one pulling from ground and the other from the plus pole .

And this is how i build it ,worked right away that was my third jt so the pickup coil can be improved quite a bit  base resistor value also ...

Thanks Mark

I see on my  data sheet that  MJ2955  is  the  PNP equivilent  to the 3055
That  would be my  first choice .

Abra  electronics  has them

It is possible that  tip2955 and  tip3055 might  be easier to find.
it looks to me like they are the same  transistirs in a newer  package .
The  data sheet  seems to be  about the same ........ I have  the Motorola data sheet .
Near the  bottom it says .
NOTE: For additional design curves, refer to electrical characteristics curves of 2N3055.

gary