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Author Topic: Lasersaber strikes again. A joule thief king ?  (Read 412369 times)

d3x0r

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #60 on: May 12, 2014, 05:52:48 PM »
so?
sorry ; foils are different than I thought... they're both on the secondary...but not on the same end... a while ago the B image would be closer but move the dot on the right side....

conradelektro

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #61 on: May 12, 2014, 06:03:43 PM »
so?

@alejandroguille

LaserSaber built his coil like shown here http://laserhacker.com/?p=401

Some people say the connections between the copper strips and the windings should be as I suggested (the drawing you posted).

Best is you build a coil like LaserSaber (the same pot core and wire) and then you lead a wire out from each of the two copper strips which you can connect in several ways till it works.

But I think that nobody knows for sure whether the copper strips do anything important and how they should be connected. I also think that the germanium transistor 2N1304 he uses might help to reduce power draw because it has a very low base current and less perfect switching (less collector emitter current if on). I could find some 2N1304 on eBay (not yet delivered), but getting the pot core in Europe is not so easy (that is why I use a different core).

But may be you wait till LaserSaber publishes his latest circuit from his video http://www.youtube.com/watch?v=6B79UJGoNJE

Greetings, Conrad

NickZ

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #62 on: May 12, 2014, 06:33:54 PM »
  Many of the ferrite e-cores that are used in pc monitors and tv sets use a copper strip on the outside of the ferrite core, so there must be a good reason for this.
  Those that can't find copper foil, might try using a strip of aluminum cut out of a soda can.

alejandroguille

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #63 on: May 12, 2014, 07:44:01 PM »
@alejandroguille

LaserSaber built his coil like shown here http://laserhacker.com/?p=401

Some people say the connections between the copper strips and the windings should be as I suggested (the drawing you posted).

Best is you build a coil like LaserSaber (the same pot core and wire) and then you lead a wire out from each of the two copper strips which you can connect in several ways till it works.

But I think that nobody knows for sure whether the copper strips do anything important and how they should be connected. I also think that the germanium transistor 2N1304 he uses might help to reduce power draw because it has a very low base current and less perfect switching (less collector emitter current if on). I could find some 2N1304 on eBay (not yet delivered), but getting the pot core in Europe is not so easy (that is why I use a different core).

But may be you wait till LaserSaber publishes his latest circuit from his video http://www.youtube.com/watch?v=6B79UJGoNJE

Greetings, Conrad

ok, thank you very much!.

conradelektro

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #64 on: May 12, 2014, 08:25:07 PM »
LaserSaber published his latest circuit, see at http://laserhacker.com/?p=406

He seems to use the coil as described here http://laserhacker.com/?p=401

Attached please see a circuit diagram which compares my replication with his creation. My replication is much worse concerning run time with an electrolytic  capacitor. LaserSaber's creation runs for many minutes with a 3000 µF cap, mine only runs about 2 minutes with a 4700 µF cap.

You can see more details here http://www.overunity.com/14591/lasesaber-strikes-again-a-joule-thief-king/msg402222/#msg402222


I am waiting for the delivery of some 2N1304 germanium transistors (bought on eBay), but I will add a copper strip to the outside of the second winding (which is connected to the base of the transistor, after removing the unused third winding). We will see if it changes anything. The copper strip on the outside can easily be added and removed again.

I want to try the coil with a 2N1304 transistor before completely dismantling and rewinding it with two copper strips, one of which should be the first layer. We need the comparison of a coil with and without copper strips.

Before going into pot cores I want to do tests with this more conventional core.

Greetings, Conrad

alejandroguille

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #65 on: May 12, 2014, 08:37:01 PM »
LaserSaber published his latest circuit, see at http://laserhacker.com/?p=406

He seems to use the coil as described here http://laserhacker.com/?p=401

Attached please see a circuit diagram which compares my replication with his creation. My replication is much worse concerning run time with an electrolytic  capacitor. LaserSaber's creation runs for many minutes with a 3000 µF cap, mine only runs about 2 minutes with a 4700 µF cap.

You can see more details here http://www.overunity.com/14591/lasesaber-strikes-again-a-joule-thief-king/msg402222/#msg402222


I am waiting for the delivery of some 2N1304 germanium transistors (bought on eBay), but I will add a copper strip to the outside of the second winding (which is connected to the base of the transistor, after removing the unused third winding). We will see if it changes anything. The copper strip on the outside can easily be added and removed again.

I want to try the coil with a 2N1304 transistor before completely dismantling and rewinding it with two copper strips, one of which should be the first layer. We need the comparison of a coil with and without copper strips.

Before going into pot cores I want to do tests with this more conventional core.

Greetings, Conrad


thank you!

Pirate88179

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #66 on: May 13, 2014, 02:14:30 AM »
  Many of the ferrite e-cores that are used in pc monitors and tv sets use a copper strip on the outside of the ferrite core, so there must be a good reason for this.
  Those that can't find copper foil, might try using a strip of aluminum cut out of a soda can.

Not a bad idea Nick, but I would caution folks to burn off the plastic liner used on the inside of the cans to allow electrical contact in case that is important.  A simple continuity test could show if the liner has been removed enough.

Bill

d3x0r

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #67 on: May 13, 2014, 03:49:55 AM »
2n1304; these are kind of hard to find; only a few germanium transistors are being produced apparently.


saw this demo; they do guitar effects pedals and explain the difference between germanium and silicon diodes for this application..
https://robertkeeley.com/2013/09/germanium-transistors/


lost_bro commented that it has a 0.22V Vbe on.  That's incredibly low; and I can't find any silicon near that.


Did buy some 34/22 3000 perm pot core and some mc34063;


If someone stumbles on a replacement part for the 2n1304 I'd be interested
« Last Edit: May 13, 2014, 06:43:06 AM by d3x0r »

conradelektro

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #68 on: May 13, 2014, 07:51:03 PM »
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

Dave45

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d3x0r

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #70 on: May 13, 2014, 08:10:08 PM »
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

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #71 on: May 13, 2014, 08:56:17 PM »
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

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #72 on: May 13, 2014, 09:02:15 PM »
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

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #73 on: May 13, 2014, 09:16:21 PM »
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

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Re: Lasesaber strikes again. A joule thief king ?
« Reply #74 on: May 13, 2014, 10:02:25 PM »
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.