Joule Thief

[WayneJT]

Bill

has no one tried to tap into that trigger coil you are talking about...2000 + volts from a 1.5v battery sounds to me like it must be useful for some lighting even if the cap is used.

I will take your advise and go out and buy a Fuji with the black switch as this seems to be the one that lights up all of those Leds.

Wayne

[Pirate88179]

Wayne:

To my knowledge, the problem with the trigger coils is that it needs a large voltage "burst" like it get from the large cap.  This only last for a second but that is all it needs.  It can not be constantly driven by the transformer, the juice is just not there.

Think of a bucket of water...(the cap)  it takes a while to fill it but then you can dump a bunch of water out all at once...but once the bucket is empty...it must be filled again.  It can not continue to put out that volume of water continuously.

That is my understanding anyway.  I am no expert by any means.

Bill

[crowclaw]

Wayne:

To my knowledge, the problem with the trigger coils is that it needs a large voltage "burst" like it get from the large cap.  This only last for a second but that is all it needs.  It can not be constantly driven by the transformer, the juice is just not there.

Think of a bucket of water...(the cap)  it takes a while to fill it but then you can dump a bunch of water out all at once...but once the bucket is empty...it must be filled again.  It can not continue to put out that volume of water continuously.

That is my understanding anyway.  I am no expert by any means.

Bill

Spot on Bill,  Merv

[Pirate88179]

Merv:

Thank you.

Bill

[protonmom]

It looks to me as though the camera companies recycle the good parts and put them on a new board each time a camera comes back in.  I have found  you can never tell exactly which  board you will get by just looking at the box or the button.  Many times I have opened two of the exact same box, and found a different board in each.

I was working on a 230 board by Fuji, and I tried out the trigger coil along with the normal setup.  My tester LED lit very brightly and stayed lit for a long time, but then there was suddenly a puff of smoke, which I assume was the tranny…..but the LED remained lit.  I found it odd that the led was still lit even though the tranny had expired.  I removed the battery, and felt the components to see if any were hot, but none were.  I then tested the transistor, and it showed a reading on both legs with the pos on the base.  So, maybe the transistor did NOT fry.  Maybe it was the transformer…but if it was the transformer, then why did the led remain lit after the puff of smoke?  Or, did the trigger coil still have enough juice in it to keep the led lit for that period of time until I removed the battery?  Or, maybe it was the battery that puffed?  But the battery still works.  So what was the puff of smoke? 

Here is a pic of my latest cfl creation….the protonM, using fuji of course!  Not bad for a cfl running off an AA battery.