[FARC] Joule Thief, That dead battery Voltage Booster project
Philip Karras
ke3fl at yahoo.com
Fri Jan 24 04:58:58 EST 2014
"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/null/
"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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