Joule Thief

[Flux4Energizer]

I just uploaded the continuation of my PIC controlled Joule Thief with Feedback 2 Source on to youtube.
For those who like to see it here's the link: http://www.youtube.com/watch?v=XlfWSlf3BGk
While this video was uploading i was shooting another continuation with a few modifications in the circuit.
The mods i did because nievesoliveras (Jesus) pointed out that the feedback loop had a flaw in it!

@flux4energizer

What you did is what I am studying now. I mean the part of using a pic programmer.

The feedback to the source is not correct. You are charging a battery that is not the source.  Pay attention that the source are the 4 AA batteries.
Nice job!

Please post a schematic if it is not too much to ask.

Jesus

I was quit astonished that he was the only one who pointed out this fact; i really thought that everyone
here on the forum and over on youtube would point out this flaw but nobody did!!!
But this said, i totally agree with nievesoliveras (Jesus); the feedbackloop isn't right.
There is a small amount of energy 'leeking' from the batterypack to the run battery.

I want to point out that these first videos are just for my own educational purpose only.
My main goal was to create a working F2S (feedback 2 source) and i think i succeeded on that part.
The weird thing was that i saw the run battery climb up in voltage so i thought i make a video of it.

So this all said, comming back on the new video i just recorded with the modifications in them.
I modded the circuit using a opto coupler instead of a transistor to isolate the two circuits.
I will upload the video a.s.a.p.

Regards,

Flux 4 Energizer

[Flux4Energizer]

Just uploaded my latest video.
Modded JT with F2S video.
The circuit now holds a opto coupler.
Here is the link: http://www.youtube.com/watch?v=MXtJ8grIFWc

Would like to hear your comments or ideas on this!!!

Regards,

Flux 4 Energizer

[nievesoliveras]

@flux4energizer

Nice 2 videos.

I have questions from the schematic you uploaded to us.
1. There is a connection coming up from the junction of the two 10k resistors of the transistors. Is it forgotten and not connected or its just a drawing slip?
2. The transistor emitters or ground connection are connected to a 16v 10uf capacitor that feeds from positive. Is that correct?

Thank you for sharing your work with us.

Jesus

[Flux4Energizer]

@flux4energizer

Nice 2 videos.

I have questions from the schematic you uploaded to us.
1. There is a connection coming up from the junction of the two 10k resistors of the transistors. Is it forgotten and not connected or its just a drawing slip?
2. The transistor emitters or ground connection are connected to a 16v 10uf capacitor that feeds from positive. Is that correct?

Thank you for sharing your work with us.

Jesus

Thanks Jesus,

The junction on the 2 10K resitors will be your external power source positive connection (this you'll need for the newer type PIC's).
They need at leat 10 Volt at the MCLR to be able to program them.
So you'll connect a 12 - 16 volt power supply at that connection the 13v zener will then zener it to it's needed voltage.

The 16V 10uF is being supplied from the sub-d itself and is placed there to stabilize the 5 volt comming of your serial port.

Regards,

Flux 4 Energizer

[nievesoliveras]

Thank you @flux4energizer!