Joule Thief

[jadaro2600]

This is also funny, because not everyone has VHS tapes anymore, or heat resistant enamel paint for that matter ( as I mentioned ) ..I like your idea though, ..using the tape as a core crossed my mind before also - though, I never actually tried it.

I used to have a bunch of tapes, big and small, for whatever reason they were thrown away though.  I have a few small ones, I might try to implement an inversion of what you just mentioned, and place the tape around the outside.  Post a Picture if you can, you've made an innovation.

Lately my joule thiefs have been working without capacitors, but this probably has something to do with my LED's I'm using.

[Mk1]

@all

the toroid , there are many thing to know , first the need to circuit to switch in there range , they decide , some need more turns to be effective with those you can still get 30 v dc pickup coil , if you go bifilar all around the toroid , make sure to not go over the the the ends of the jt coils. In a better toroid you can go lower jt coil turns , but there only good at there own frequency , now if you want instant gratification stick to ferrite core most are good , what is cool about it is that it works at a wider range of freq , so you should get result for the get go , that said they need testing to be sure the design could not be improved . Some need more voltage those are bad for this toy.

Keep those wires tight !

Mark

[Mk1]

The  voltage  I was talking about is  measured by hooking a bridge   across the  diode .......then  a cap  to the bridge  and messuring the  voltage  on the cap     I got  2.9v  for  the  bifilars separately  and  2.7V with them in parrallel

I get confused , but i just want to make sure didn't use bridge and diode , so could you give more details

[jadaro2600]

I hate to interrupt any thought processes here, but is it maybe a good idea to use switching diodes to rectify the current coming off pickup coils?  ( 1N914/1N4148 ) seems to support signals up to 100mHz...they're also cheap and abundant.

[resonanceman]

I get confused , but i just want to make sure didn't use bridge and diode , so could you give more details

MK1

As far as I know the  best  way to measure the output  of a JT is by rectifying the  output  with a diode bridge  then  charging  a cap  with the bridge .........that is what I was doing .


gary