[FARC] Joule Thief, That dead battery Voltage Booster project

[David Kindred]

That Mark is one smart gentleman!

Thanks for sharing your experiences, Phil, and the links. I would have had
NO clue how to debug the problems and would've needed help from a generous
ham, like Mark, as well.

73,

--David, K3PO

-----Original Message-----
From: farc-bounces at mailman.qth.net [mailto:farc-bounces at mailman.qth.net] On
Behalf Of Philip Karras
Sent: Friday, January 24, 2014 4:59 AM
To: ccarc; Frederick AmateurRadioClub; Mid Atlantic
Subject: Re: [FARC] Joule Thief, That dead battery Voltage Booster project

"Making A Simple Joule Thief (made easy), by ASCAS" :
http://www.instructables.com/id/Making-A-Simple-Joule-Thief-made-easy/

I want to thank everyone who tried to help for all the suggestions. I have
my circuit working thanks to Mark, AB3KS who invited me over to his place in
Frederick. We looked at what I had done and he pointed out that I had
attached the wrong wires of the wound toroid together making mine into a
non-inductance winding. See wiki: Bifilar coil
https://en.wikipedia.org/wiki/Bifilar_coil This shows the Non-inductive
bifilar winding connections which is how I connected my toroid. I totally
missed the importance of the two dots on the windings in the schematic.

Someone may know so I'll ask, of what use is the non-inductive version?

Anyway, once correctly connected my circuit was working just fine. I
discovered that a Tor-62 core, wound with 25 loops has an extremely low
inductance of about 45 uH measuring between the two ends so that 50 loops
are being measured. With only 25 loops measured my meter registers 000. This
inductor then causes an oscillation I measured of around 500KHz with a 1
Volt battery where as a single 20 loop inductor measured at about 120 uH
causes the circuit to oscillate at about 5KHz.

Here are some other links I came across after Mark helped me, some of which
clearly showed what I was doing wrong and others show much more clearly how
to do it correctly.

Joule thief
http://en.wikipedia.org/wiki/Joule_thief

Good schematic and O-scope trace shows what my scope showed.
http://www.bigclive.com/joule.htm - Clearly shows how to connect the
windings of the ferrite cord inductors.

"Joule Thief" Circuits, crude to modern... by Dave Kruschke
http://www.instructables.com/id/Joule-Thief-Circuits-crude-to-modern/step5/n
ull/

"Joule Thief" - no IC and no Transformer, by Dave Kruschke
http://www.instructables.com/id/Joule-Thief-no-IC-and-no-Transformer/

73 de KE3FL,
Phil
AEC Carroll County
OES, ORS, & VE
http://cs.yrex.com/ke3fl
Karras' Corner: http://blog.solidsignal.com/content.php/1005-karras-corner
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