Lasersaber strikes again. A joule thief king ?

[d3x0r]

I added a copper strip to the outside of the coil (see attached photo). The third winding has been removed.

The circuit is still the same, see:
http://www.overunity.com/14591/lasesaber-strikes-again-a-joule-thief-king/msg402255/#msg402255
http://www.overunity.com/14591/lasesaber-strikes-again-a-joule-thief-king/msg402222/#msg402222

With the copper strip (and an unchanged circuit) the power consumption has gone up considerably fom less than 1 mA to 6 mA at 1.5 Volt (more at higher Voltages). The LED shines brighter. The circuit also has problems starting up, most of the time one has to touch the copper strip to start oscillation.

Connecting the copper strip to any winding (at any side) has no discernible influence on the behaviour of the circuit.

The copper strip has changed the properties of the coil towards more power consumption and start up difficulties (with the same circuit as before addition of the copper strip). The circuit has to be changed to accommodate the chages in the coil.

Greetings, Conrad

looks like this copper strip is shorted; this will be just a loss since the electrons will just freely float around that... something like barbosa-and-leal thread where there's a third, closed winding....

but the akula video clearly shows a notable gap in both the inner and outer foils... these should generate alterating +/- potentials on the edges... mind you it's only most of a turn, so it's going to be a huge step-down in voltage

[conradelektro]

looks like this copper strip is shorted; this will be just a loss since the electrons will just freely float around that... something like barbosa-and-leal thread where there's a third, closed winding....

but the akula video clearly shows a notable gap in both the inner and outer foils... these should generate alterating +/- potentials on the edges... mind you it's only most of a turn, so it's going to be a huge step-down in voltage

We also do gaps. Thank you for the observation.

With a gap in the copper strip (see attached photos) I am back to the original situation (power draw about 0.5 mA) as shown here:
http://www.overunity.com/14591/lasesaber-strikes-again-a-joule-thief-king/msg402255/#msg402255
http://www.overunity.com/14591/lasesaber-strikes-again-a-joule-thief-king/msg402222/#msg402222

Connecting the copper strip (with gap) to any winding does not have a discernible effect. It is like the copper strip (with gap) has no influence at all and does not change the properties of the coil.

It is interesting that a closed or shortened copper strip (as in my last post) does have an effect (although decremental).

I know, there should also be a second copper strip as a first layer. But I am waiting for the 2N1304 transistors before dismantling the coil to add the second copper strip (with gap).

Greetings, Conrad

[d3x0r]

We also do gaps. Thank you for the observation.

With a gap in the copper strip (see attached photos) I am back to the original situation (power draw about 0.5 mA) as in here:
http://www.overunity.com/14591/lasesaber-strikes-again-a-joule-thief-king/msg402255/#msg402255
http://www.overunity.com/14591/lasesaber-strikes-again-a-joule-thief-king/msg402222/#msg402222

Connecting the copper strip (with gap) to any winding does not have a discernible effect. It is like the copper strip (with gap) has no influence at all and does not change the properties of the coil.

I know, there should also be a second copper strip as a first layer. But I am waiting for the 2N1304 transistors before dismantling the coil to add the second copper strip (with gap).

Greetings, Conrad

well... that's nearly as depressing as https://www.youtube.com/watch?v=4wSPZxQXYR4; which indicates just pulsing will extend the runtime a very very long time...


thanx... would it be possible to slip a copper sleeve between the bobbin and core inside; without unwinding...

[conradelektro]

thanx... would it be possible to slip a copper sleeve between the bobbin and core inside; without unwinding...

I will try tomorrow, but the copper foil will be separated from the first winding by the plastic of the coil former (about 1 mm thick). I might have to use a very thin aluminium foil (because there is not much space between core and coil former). Again, a good idea, thank you.

I think it is the transistor 2N1304 which for some reason allows for very narrow pulses on the base (very short on time of the transistor). If the pulses are 10 times shorter than in my circuit (with the BC547C) one would be down to 50 µA (from 500 µA) which would mean a 20 minute run time with the 4700 µF cap.

Greetings, Conrad

[TinselKoala]

For comparison purposes...

http://www.youtube.com/watch?v=BQi4jz2puio

If you get bored, you can skip ahead to around 11:00 for some interesting action.

I'm using a much lower value base resistor than LS so I get a much brighter light, at the expense of current draw and runtime. But of course one can always vary this parallel RC part to optimize for runtime or brilliance.