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Author Topic: Experiments and Anomalies  (Read 133194 times)
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Apart from the pulsing aspect of the SJL, Lasersaber makes a fundamental error in assuming the current measurement for the high frequency / pulsating LED's is the same as for the LED's driven by continuous current, as measured by an analogue meter of this moving coil type, which is not designed to take AC / pulsating DC current measurements.

Hoppy
« Last Edit: 2014-05-15, 08:41:50 by Hoppy »
   
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It's turtles all the way down
slider said:
Quote
Do you have an LED circuit that would raise the bar here ? Something we might in fact assist LS with, by replicating ?
It would cut the stumble, which is a very good point if we can build on and with that library.

Unfortunately there is no bar or standard goal except perhaps run time. Power output of the lights is not "standardized" or even measured as a goal.
Is the LED visible in a darkened room? in normal light? in outdoor sunlight? under a microscope? Is there a standard LED to be used by participants?

Nor is voltage and current input measured. If you are only looking at uA draw it is only a part the story. P=ExI

For a contest or to see if one is really making progress, it is necessary to nail down some of the parameters e.g most optical power delivered for one hour by XXX type battery or xxx uf capacitor. Besides accurate measurement, you  need to take lab notes to see if you are really making an improvement.

Be it a soap box or formula race, certain constraints are needed to be spelled out. If there are no constraints or no goals, then it is easy.

So I will ask slider and all few questions for starters. Right now the goal is nebulous. Define exactly the goal.

Which of these would be a viable constraint or goal:

Power input
Run time
Amount of optical power delivered (How is the output measured eye or sensitive light meter, peak or average power?)
Number of active components allowed
Number of passive components allowed
Size of the assembly*
Weight of the assembly*
*(including power source)

It is well known in the art that pulsing an LED can be a large advantage in apparent light output to the eye over steady DC current so LS's latest video and test is not a revelation.

That is one of the reasons multiplexed LED displays have been popular for the last 45 years or so.
« Last Edit: 2014-05-15, 15:06:42 by ION »


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Well reading from post 39 onward's,my first thought was-here we go again,the big gun's telling the small fries that there is nothing special with what were doing,but have no input as to how we could make thing's better. We see this all the time,on all of the forum's-EF more than most. But reading ION's last post,he dose have a good point. What exactly are we trying to achieve?

Quote ION: people are fooling themselves if they think there is anything special about Lasersaber circuits.

Looking back on many of my experiments,he is right-there is nothing out of the ordinary happening with LS JT circuit's.
Slider-look back at the work you done on the cool joule setup,and the variation's you made on it.I think that was right up there(if not better)than any of LS SJR circuit's.

Then there is my window motor i made ,with mag lev bearing's-have a look at how efficient that was-and this is spinning a good sized rotor.
https://www.youtube.com/watch?v=67R5ksfFF14


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Well reading from post 39 onward's,my first thought was-here we go again,the big gun's telling the small fries that there is nothing special with what were doing,but have no input as to how we could make thing's better.


That's a bit harsh on the ninnies IMO.   :'( The big message to the small fry is make sure the measurements are fit for purpose before being swallowed by the sharks. In this respect much has been said on the subject and practical advice given by the ninnies. Remember the pre-occupation on the FE fora is debating whether this or that device being claimed as self-running, is in fact self-running. To do this we all need good quality documentation and measurement data for replication, which is very rarely available.

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That's a bit harsh on the ninnies IMO.   :'( The big message to the small fry is make sure the measurements are fit for purpose before being swallowed by the sharks. In this respect much has been said on the subject and practical advice given by the ninnies. Remember the pre-occupation on the FE fora is debating whether this or that device being claimed as self-running, is in fact self-running. To do this we all need good quality documentation and measurement data for replication, which is very rarely available.

Hoppy

Such a small statement to pull from a much larger post Hoppy-makes me look bad lol.

I believe there is a way to make a self running device,but the materials to do this,i just dont have. But will be getting in touch with slider-maybe he can get the required materials together.


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Such a small statement to pull from a much larger post Hoppy-makes me look bad lol.

I believe there is a way to make a self running device,but the materials to do this,i just dont have. But will be getting in touch with slider-maybe he can get the required materials together.

Have you thought about scaling-up your Window Motor and comparing efficiency with a conventional PM motor? I'm quite impressed with your WM demo. Would you share the circuitry with others on this forum?

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Have you thought about scaling-up your Window Motor and comparing efficiency with a conventional PM motor? I'm quite impressed with your WM demo. Would you share the circuitry with others on this forum?

Hoppy
I would be happy to share the circuit Hoppy. But i must warn you,this circuit caused quite a bit of trouble over at TEEP(when i was a member there).How ever,this trouble led to a new forum being built by myself and a man called timber jack.That forum ofcourse is the IAEC.The circuit is on that forum,but at the moment,all forumco forum's seem to be down???. I will dig it up for you as soon as i can. But i would like you to watch the following video,and this may explain as to why i am a little critical of those that think they are above and beyond other experimenters.I was one of the !small fry!,that loved trying all sorts of different combinations of circuit's. the one the window motor is running,was by far the best one i came up with. But it seem'd that one of the moderator's of TEEP decided that my circuit was dangerous,and could explode at any time.This resulted in him stopping all my post-even though i had shown a video of the circuit running quite fine.All other member that came to my aid,and said the circuit was quite safe,were banned for 3 day's.
Anyway-this is the result from one of those member's.

https://www.youtube.com/watch?v=70T7NrYXM_4


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@Tin Man,

Unfortunately, I get an error on the link you gave.

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I've been thinking of writing up a primer on LED pulser circuits. This would include:

Capacitor discharge type

Inductive discharge type

Brute force from power source type,

It would include techniques for building regenerative switches, simple 2 transistor multivibrators SCR, PUT, unijunction, optimizing flyback converters, blocking oscillators (aka Joule Thief and many other methods, including a circuit description what is actually occuring in Lasersabers latest offering.

I talked about goals and constraints because I've worked as a designer in industry where the circuits I came up with were produced by the tens of thousands or even hundreds of thousands. some went into millions of units sold.

When doing this the engineer must have a target goal for the end product, a set of specifications that he must shoot for, then explore every means to build the circuit.

 In the final analysis he should use thrift in the design such that unnecessarily expensive or material wasting approaches are not used, yet the circuit must be robust and deliver uniform performance over a wide range of tolerances stack up in the components, temperature, humidity etc.

Where cost is no object, and these other factors are not considered, such as if you are producing a one- off for your own use with exotic or costly materials, then we are talking a whole new ball game.

But again I ask what is the goal? Any contest must have specific rules spelled out clearly.

Who can state the contest rules for the LED pulser?


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@Tin Man,

Unfortunately, I get an error on the link you gave.

Hoppy
I just tried it Hoppy,and seems to work fine for me ???.


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I just tried it Hoppy,and seems to work fine for me ???.

OK, got it now, thanks.
   

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I've been thinking of writing up a primer on LED pulser circuits. This would include:

Capacitor discharge type

Inductive discharge type

Brute force from power source type,

It would include techniques for building regenerative switches, simple 2 transistor multivibrators SCR, PUT, unijunction, optimizing flyback converters, blocking oscillators (aka Joule Thief and many other methods, including a circuit description what is actually occuring in Lasersabers latest offering.

I talked about goals and constraints because I've worked as a designer in industry where the circuits I came up with were produced by the tens of thousands or even hundreds of thousands. some went into millions of units sold.

When doing this the engineer must have a target goal for the end product, a set of specifications that he must shoot for, then explore every means to build the circuit.

 In the final analysis he should use thrift in the design such that unnecessarily expensive or material wasting approaches are not used, yet the circuit must be robust and deliver uniform performance over a wide range of tolerances stack up in the components, temperature, humidity etc.

Where cost is no object, and these other factors are not considered, such as if you are producing a one- off for your own use with exotic or costly materials, then we are talking a whole new ball game.

But again I ask what is the goal? Any contest must have specific rules spelled out clearly.

Who can state the contest rules for the LED pulser?
I have always found that a friendly contest brings out the best in design's-like the pulse motor build off's myself and Russ have held.\
Maybe we pick a V/input amount,and then using one of the small solar garden light led's and solar pannel,we make a light box,and send the power from the solar pannel to a cap with a resistor(of say 100 ohms) across it,and see who can get the lowest P/in for the highest P/out. But as this is Sliders thread,maybe he could give the specific's of the test setup.


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LaserSaber modifies circuit, adds diodes, reaches a 5-hr run on 3300 uF cap.

http://www.youtube.com/attribution_link?a=BnUoHNCcpdU&u=/watch%3Fv%3DFOUrRXINDqY%26feature%3Dem-uploademail

New circuit given (see link with vid). 

He's talking about a flashlight device at this point.
   

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LaserSaber modifies circuit, adds diodes, reaches a 5-hr run on 3300 uF cap.

http://www.youtube.com/attribution_link?a=BnUoHNCcpdU&u=/watch%3Fv%3DFOUrRXINDqY%26feature%3Dem-uploademail

New circuit given (see link with vid). 

He's talking about a flashlight device at this point.

Ah come on-are you kidding me???. OK-this is getting built tomorrow,and i do have the smaller pot core's he speak's of.


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Yes, Five HOURS is pretty cool...  Looking forward to your build, Tinman.
I'm jumping in as soon as I get back to my electronics bench (this weekend or Monday.  visiting family today in Colo )

diagram shown below.  Note that the direction of the LEDs  "may need to be flipped"   Interesting...  So which way works the best?
Guess we'll find out.

   

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Yes, Five HOURS is pretty cool...  Looking forward to your build, Tinman.
I'm jumping in as soon as I get back to my electronics bench (this weekend or Monday.  visiting family today in Colo )

diagram shown below.  Note that the direction of the LEDs  "may need to be flipped"   Interesting...  So which way works the best?
Guess we'll find out.


[/quote:
I would say the LED's would have to be fliped depending on winding direction to battery polarity.Once up and running,i think i would like to try something a bit different-as pictured below.


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That really is cool O0

I will have to try this, hopefully this weekend

regards

Mike 8)


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My approach to building an efficient and practical low current LED torch would be to first ascertain its best frequency response using a FSG. In the case of my 3W LED chips, best response is when square wave driven at around 1.4Mhz.  I would then decide on the most efficient driver, which may not necessarily be a coil based oscillator. This oscillator would be capable of frequency adjustment and low frequency modulation of the optimum frequency for lowest current working v acceptable light level.

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It looks like the purpose to these experiments is becoming defined, as a flashlight.
I agree about that question...let's have a practical purpose to aim at.
Or, when it doesn't run forever in a microwave, what can we do with it ? lol

In the experiments with the earlier similar circuit, Itsu mentioned the use of a cap across 2 points to fire it up reliably. If using a pot core with a bolt, I found that connecting a wire between the *correction at 3.08pm* positive side of the LED and bolt also fired it up. Just another method if folks encounter a dead circuit. Perhaps a Piezo BBQ lighter would work, as shown by JonnyDavro years ago for coils.

Those SMD ceramics are very appealing. For recycling from say old laptop boards, press the soldering iron against 1 end and lift to 45 degrees, then gently do the same on the other side...or then take a flashlight and spend 20 minutes hunting around on the floor  ;D
MPSA18 as a choice is interesting - http://www.redrok.com/NPN_MPSA18_45V_100mA_0.625W_Hfe400_TO-92.pdf
Darlington level current gain with tiny 50nA Collector cut off.
« Last Edit: 2014-05-16, 21:08:24 by Slider2732 »


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I would be happy to share the circuit Hoppy. But i must warn you,this circuit caused quite a bit of trouble over at TEEP(when i was a member there).How ever,this trouble led to a new forum being built by myself and a man called timber jack.That forum ofcourse is the IAEC.The circuit is on that forum,but at the moment,all forumco forum's seem to be down???. I will dig it up for you as soon as i can.

Hi,

Would it be interesting to see what you did out of B-e-d-i-n-i stuff and others.
We are all in same jungle running on different circles around same stones.... ;)


P.S> For some reason B-e-d-i-n-i (######) got filtered in forum. Peterae, can you check if profanity filter works correctly?
   
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@T-1000 Yeah, that happened a while back. As I understand it, Mr. Berdini apparently found something amiss with how his work was being discussed on this forum and that resulted in his name being a word for the profanity list !


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Regarding the latest LS circuit:

The Lasersaber circuit is unique in that it uses the small interwinding capacitance of the first and second windings to couple the switch on / switch off current to the base of the transistor allowing for a fast charge / discharge of base current, hence efficient switching of the transistor. This is less dissipative and provides stiffer peak current base drive than most JT circuits which use just a resistor. The interwinding capacitance also effectively limits "on time" by discharging, thus preventing saturation, hence the high switching efficiency.

The XEE2 circuit adds a small capacitor across the bias resistor to effect fast switching. This is commonly called a speedup network in the art. There are even better ways to effect base drive, depends on the goal, which is never carefully or clearly defined.

The waveform is not unique, I can get the same waveform and duty cycle with a totally different circuit and with just one winding.

If you want to increase inter winding capacitance and get more of a kick into the base of the transistor, you could lightly twist the two wires and wind them as a pair instead of separate layers.

What LS circuit does is provide a very sharp pulse with very low duty cycle, hence the long run time. LED's put out a lot of light with very short high current pulses, but it also shortens their life if you exceed the peak current rating.

The pot core and circuit is not the only way to get this sharp pulse, there are numerous methods.


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Regarding the latest LS circuit:

The Lasersaber circuit is unique in that it uses the small interwinding capacitance of the first and second windings to couple the switch on / switch off current to the base of the transistor allowing for a fast charge / discharge of base current, hence efficient switching of the transistor. This is less dissipative and provides stiffer peak current base drive than most JT circuits which use just a resistor. The interwinding capacitance also effectively limits "on time" by discharging, thus preventing saturation, hence the high switching efficiency.

Well not unique,as i posted in reply 31 on this thread.This is one of his earlier versions that i found ran in the same way-quite by mistake. I knocked the emitter wire of the globe by mistake,only to find it kept running.
https://www.youtube.com/watch?v=U-LAc52pOZ0


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Hoppy

I'm too old school (and cheap) to buy expensive chips to light LED's when I can do a good job with a two transistor multivibrator circuit, although those parts are nice all in one solutions and very efficient. I've got tens of thousands of transistors in stock.

Also, I'm not really interested in entering any contest where the light output is so dim as to be unusable just to get the extended run time as the goal. In the end, you've got to expend some power if you want a usable flashlight, and it all boils down to the efficiency of the LED's and the driving circuit. I haven't seen any magic here.

I also would encourage folks to read the data sheets of LED's carefully such that they limit peak currents and not prematurely degrade the LED's light output.

Tinman: I was just giving LS a small kudo. The use of interwinding capacitance to help along a blocking oscillator is certainly not new.


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