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Author Topic: Lasersaber strikes again. A joule thief king ?  (Read 412379 times)

Farmhand

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #285 on: July 06, 2014, 01:02:01 AM »
Nice work Tinsel, I noticed those little logic gates are very sensitive like that. It can be an interesting and a useful thing to be able to
detect signals and either collect them as Pirate said or amplify them. And the simpler the circuit the better.

Another part for the "Wanted" list.

Did anyone notice if Lasersaber ended up getting some dollars back on his prototypes ? I think a lot of us deserve to be able to
make some money back on working prototypes if we choose. Doing so might improve the build quality of some people like me as well.
Not that we all should go and buy 3D printers or anything.

..

P.S. If we sell a prototype we should include a schematic drawing on paper and a maybe a PDF or something with some information
and disclaimer with safety warning "if needed".

..

Pirate88179

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #286 on: July 06, 2014, 01:19:12 AM »
This one is powered by the CR2032 or other 3v battery. The transistor is a very sensitive, high input impedance FET, a field effect transistor. The ambient electric field (DC from a charged piece of plastic, or AC from a Tesla coil or Slayer Exciter type circuit) is picked up (charges or discharges) by the Gate of the transistor which opens the channel from Drain to Source, lighting the LED with power from the battery. The field just switches the transistor, it doesn't power it.
So this is different from the electrosmog harvester, which is actually powered by resonating with the electromagnetic field of the smog source. The electrosmog harvester needs its power source to be AC RF at its resonant frequency. The Electrostatic Field detector  isn't powered by the field, and works best with a DC field produced by a static charge, either positive or negative, but it will respond to an AC field too but not as strongly.
It's a neat little circuit and should work with most any high-impedance FET. A CMOS logic gate can also be used but doesn't give the graded quasi-linear response to the field strength the way the FET does.
It's pretty  neat to be able to control the brightness of the LED by wiggling a piece of charged plastic a meter away. The charge can be from rubbing a comb thru your dry hair, or acrylic plastic against cloth, or the E field of a tesla coil, or etc.  The actuating charge builds up on the gate so this distance will change as the gate charge leaks onto or off of the gate. I tried a 10 meg resistor as pullup or pulldown for the gate, didn't work, must use at least 100 meg I guess.

Duh!  I saw the mention of the 2032 and skipped right over it.  Still, I think the idea of being able to run a single led from ambient energy (electrosmog) would be a worthwhile endeavor.  I have this ongoing argument with a buddy of mine who is an engineer. (electronics)  He claims that if I harvest energy from a local radio station (50,000 watts) it will cost them more money and they will have to up their output.  My argument is that that transmitter has no idea if one radio is tuned in, or 150,00 radios.  He says I am wrong.  He especially got mad when I asked if his engineering degree was mail order.  Go figure.

Bill

SeaMonkey

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #287 on: July 06, 2014, 03:00:42 AM »
Quote from: Pirate88179
I have this ongoing argument with a buddy of mine who is an engineer. (electronics)  He claims that if I harvest energy from a local radio station (50,000 watts) it will cost them more money and they will have to up their output.  My argument is that that transmitter has no idea if one radio is tuned in, or 150,00 radios.  He says I am wrong.  He especially got mad when I asked if his engineering degree was mail order.  Go figure.

The Ground Wave Losses in AM Band propagation are
enormous within the several mile radius of the transmitting
antenna as losses within the soil and all metallic objects in
the signal path including the electrical grid.  Only about 50%
of the radiated energy from the antenna becomes sky-wave
or long range (more than ten miles) radiation.

Any energy your "harvester" may extract from the ground wave
would not even be noticed by the station. Even if you were able
to capture several hundred watts.

magpwr

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #288 on: July 06, 2014, 04:49:06 AM »
The Ground Wave Losses in AM Band propagation are
enormous within the several mile radius of the transmitting
antenna as losses within the soil and all metallic objects in
the signal path including the electrical grid.  Only about 50%
of the radiated energy from the antenna becomes sky-wave
or long range (more than ten miles) radiation.

Any energy your "harvester" may extract from the ground wave
would not even be noticed by the station. Even if you were able
to capture several hundred watts.

hi SeaMonkey,

This is something interesting you mentioned about the power output of actual transmitting AM station.

I'm now curious what is the estimated electrical power usage in watt or kilowatt of a typical AM station transmitter.I have not started searching yet merely for knowledge purpose at this moment.

-----
Just found a very interesting less known facts about actual transmitter stations.
http://www.oldradio.com/current/bc_am.htm

quotes from site for ref-
In 2000, WHO, Des Moines, IA, with a 300 degree tall, sectionalized radiator has the highest reported efficiency of 471.54 mV/m/kW at 1 km. With it's 50 kW input, the radiated field is equivalent to 85 kW input to a "conforming" radiator.

A directional station, WWL, New Orleans generates a reported 3934.902 mV/m at 1 km

INTERNATIONALLY -  Continental Electronics has delivered AM transmitters at the 2 Megawatt level to the broadcasting organizations of several countries. It is reported that several fought a tendency for this level of RF power to melt and fuse the insulators and sand around the tower.

 

SeaMonkey

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #289 on: July 06, 2014, 07:21:40 AM »
Quote from: magpwr
-----
Just found a very interesting less known facts about actual transmitter stations.
http://www.oldradio.com/current/bc_am.htm

quotes from site for ref-
In 2000, WHO, Des Moines, IA, with a 300 degree tall, sectionalized radiator has the highest reported efficiency of 471.54 mV/m/kW at 1 km. With it's 50 kW input, the radiated field is equivalent to 85 kW input to a "conforming" radiator.

A directional station, WWL, New Orleans generates a reported 3934.902 mV/m at 1 km

INTERNATIONALLY -  Continental Electronics has delivered AM transmitters at the 2 Megawatt level to the broadcasting organizations of several countries. It is reported that several fought a tendency for this level of RF power to melt and fuse the insulators and sand around the tower.

Very interesting finds.

The WHO tower in Des Moines (300 degrees tall) is nearly a full
wavelength which is designed to reduce the ground wave portion
of the radiated field and maximize the sky-wave portion of the
radiated field at a very low angle.  High technology at work.

The WWL New Orleans directional array is a group of towers
oriented to direct the bulk of the radiated energy to the North
thus producing a beam of very intense field strength.

Many of the AM Powerhouse stations of the 30s, 40s and 50s used
such directional arrays.

If they were designated "clear channel" they could maintain their
full power throughout the night time hours.  All other stations had
to reduce their power at sunset to 5 KiloWatts or less to minimize
long distance skip which could interfere with other distant stations
sharing the same frequency.  Some went to a night time power of
1000 watts or even less so were very hard for AM DXers to copy
at night in order to obtain a QSL Card.

Radio Programming back in those years (30s through 60s) was much
different than it is today.

pavqw

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #290 on: July 06, 2014, 10:38:28 PM »
What transistor do you recommend to do experiments with JT/SJR? I've used MPSA18 but all are burned now :( I want to order some transistor from Farnell but this one is not available in low quantity.
I am searching for something very efficient but available, cost is not relevant. I prefer NPN, it could be for low power.
Also do you have tip for ferrite core?

Thanks

TinselKoala

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #291 on: July 06, 2014, 11:27:57 PM »
What transistor do you recommend to do experiments with JT/SJR? I've used MPSA18 but all are burned now :( I want to order some transistor from Farnell but this one is not available in low quantity.
I am searching for something very efficient but available, cost is not relevant. I prefer NPN, it could be for low power.
Also do you have tip for ferrite core?

Thanks

Most any NPN will work in a basic JT circuit. Most any combination of windings on most any bit of ferrite will work. Once you have a setup that works, you can start changing things around to get the best efficiency. Turns ratio, wire size, ferrite material, ferrite geometry, base resistor, capacitors, all of these and more are the variables that will determine your efficiency. Different transistors will work differently in different circuits.

Here's a video showing a bunch of different NPN transistors that will work, most of them obtained for free from CRT tv chassis.
http://www.youtube.com/watch?v=tuFWC-yyIyU

Here's another video showing my latest SooperLooper JT with some transistor data.
http://www.youtube.com/watch?v=BHI7LnVWBlY
Transistors tested in the above system, with "start" and "stop" voltages as described in the video:
2n2222a  0.436, 0.111
BC337-25  0.420, 0.102
2SC3198  0.443, 0.111
MPSA18  0.430, 0.123
2n3904  0.491, 0.177
2n3704  0.434, 0.109
1802 N711  0.425, 0.100
200-32 F340  0.427, 0.127
CEN PN3643  0.428, 0.135
9287 N710 EBC  0.436, 0.103
2n2219  0.434, 0.142
2n2219a  0.417, 0.134
2n3053  0.424, 0.127

My "Current" favorites for low voltage JTs are MPSA18, BC337-25, 2sc3198, and 2n2222a (metal can).
For high voltage (neon lights) use 2n3055 or 13003 or similar.

I have just started testing the 2sk170 FETs that I received a couple of days ago, in conradelectro's circuit.

TinselKoala

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #292 on: July 06, 2014, 11:31:40 PM »
Two great Ebay sellers are "thaishine" and "utsource". Check them for small quantities of the desired transistors.

pavqw

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #293 on: July 07, 2014, 12:45:44 AM »
Thank you very much! I've ordered some of them from Farnell, it should arrive in 1 day. I'll try 1F capacitor too :)

d3x0r

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #294 on: July 12, 2014, 05:08:51 PM »

Charging a 3000F cap; never finished charging... moved down to 100F instead to experiment...

https://www.youtube.com/watch?v=AmABqSn9ocw


Lasersaber is using 11V 1F caps which are Nek/tokin; I found them for $6.99 at a Cute Digi... they had some components but not many.
Illinois Capacitor, Inc. makes 25F 2.7V I found at allied elec for $3.39.  put 4 in series and you get 10.8V, 6.25F for $12... slightly more than double the cost for 6x the capacitance :)  But these were clearance....

d3x0r

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #295 on: July 14, 2014, 10:10:46 AM »
Was considering that maybe 'tesla torch' isn't horribly far off... "Ka4ep torch" err "kacher torch" might be better name :)
(simplified,  start resistor omitted)

second image:
My modifications end up drawing more power... but mine won't run without a cap(not sure where to put the other end; to power rail works; I have a couple other ideas to try) on the top end of the secondary (inducter to base)... and adding a diode on the primary ends up looping that energy around the coil (red circle); and doesn't affect normal run, but if a diode is additionally added from the base to ground(green), then it reduces power used....  instead of a diode the voltage is high enough to add a couple more LEDs...



Edit:
Wound a new coil that's 4 turns and lots of turns... 30uH and 27mH... on tiny ferrite... connected low inductance power->collector; and now drive a larger load at lower voltage (0.7V-1V 30-40mA); 10 5V white LED High and 10 Low.
top is full sinwave, biased a little towards the low side; no resistor.
« Last Edit: July 14, 2014, 01:00:22 PM by d3x0r »

d3x0r

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #296 on: July 14, 2014, 02:01:15 PM »
Figured out where to put the cap... between the top of the coil and the load; reduces power consumption slightly
Now base diode doesn't help under-voltage as much; only goes to a square wave of like -5V but does help power consumption slightly.
2n2222 transistor
Running frequency is about 100Khz; and reverse calculating capacitance from frequency and inductance yields about 93pF... which I assume is the internal capacitance of the coil... it's a nice sine wave.  Added a series capacitor to the load; too small of a capacitance fails...
Ground connection to the load can either be the low side of the cap or a real ground, doesn't affect current draw much.
Does not require startup; but I'm using a hand generator which generates slight spikes in voltage which tickles it enough I guess... I did have a 1M resistor to tickle the base but whether it's connected or not doesn't matter.


Circuit running under 2V generates +/-50V... at 2V is about 40mA consumption at 0.6V goes down to about 10-20mA.


https://www.youtube.com/my_videos_annotate?v=2D5HuxmlyjY


Edit:
Was able to add a slight recovery to power from the load... it measures that there should be a voltage change; but not very much... 50mV (x10 probe, 500mV across 100ohm resistor... 5mA + and - approximately... but it's only for a very short time... )  I think some of it is lost being in-phase with the power used... it does add a hair of brightness at no more current usage....
« Last Edit: July 14, 2014, 04:18:20 PM by d3x0r »

d3x0r

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #297 on: July 20, 2014, 04:36:26 PM »
So for a while I've been trying to figure why there's a dead space and then a sudden burst of oscillations. (on LS's device)
'ferroresonance'.  once it fires once, with the right load and various other conditions there's a burst of activity where the low voltage on collector side actually re-fires the transistor again with a slight ringdown, until another long pause before the gate voltage goes high again.  These tiny pot cores do have a very tiny gap in the center post... since if you torque a screw that doesn't go very far out cracks them.... ferrite being non malleable and very brittle.


I was targeting a higher brightness; which leads to a continuous oscillation; which leads to higher current draw. 


@TK
I was playing with a electro-smog harvester also; I thought I was close, but ended up I was just tuning to a sub-harmonic of the square wave I was testing with... most of the harvester has to be inductance? ... like if I calculate 1200000Hz (1200Khz) 2nF I get 8.7uH; which is like 8 turns of wire at about 3.5 inches... which picks up my frequency from the function generator, but gets not enough power for 1 LED... but at 33pF (533uH) how do I overcome the capacitance that's in the coil to get down to 33pF?  I mean the capacitance in just the wire exceeds that when using many feed?
I found this calculator http://hamwaves.com/antennas/inductance.html  ; but the design capacitance yields a negative number?  -9568.867751635291 
[strike]for a 5mmx50mm coil of 50 turns using 0.015mm wire ... hmm maybe I should use reasonable values [/strike]
for a 50mmx20.2mm coil of 100 turns of 32g (0.202mm) wire yields -0.785pf at 1.2Mhz frquency; (401.3uH)... hmm guess the induction is too high at that point...




I guess the capacitance should be as small as possible to get the most voltage out of it in resonance; which is what my caps between the coil and load end up doing... without the cap at the top I can't drive as high of a voltage load.
I remember from way way back when my dad made me a crystal radio; no power and it made the headset work pretty well.
Although; I don't get why the capacitance of the wire itself disappears.


--------
So then headsets; 2000ohm high impedance are sold; several look like the headphones my dad had (from military; he used to work on radar in alaska but anyway)... so not much current must be used; since (being generous) to get 12V... that's 6mA... would be curious how much current your smog harvester is actually harvesting.


some guy Evaluating 'airnergy' device from RCA that charges a battery from wifi harvesting.
https://www.youtube.com/watch?v=P8s3Xjeg0sk  (take 8 years to charge your battery)


another product http://www.powercastco.com/products/powerharvester-receivers/  power receivers for 900Mhz (phones) 23 dBm(200mW, hmm dBm relates to a log of W somehow), 4.3 V 100 mA (max)  ; (recommended usage to receive radio power and power remote sensors which in turn generate a radio signal; recycling the power)


-----
I guess falloff is (power out=100 kW/(4·pi·r2) ) for a 100kW source... so if I needed (2.7V@30mA) 0.081W, I could be 3939m from the source...
so if there was a 5MW source 500m away one could get 1.59W (5000000/(4*3.14*500*500)).  I'm not sure that would be enough for Ruslan's device.
(according to http://electronics.stackexchange.com/questions/4664/stealing-energy-from-radio-towers-or-power-lines discussion)
---
I built a resonant tank that's good for 60Hz; but I don't know how to get power into it since it's based on a pot core.

TinselKoala

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #298 on: July 20, 2014, 10:36:44 PM »
Big caps take long time to charge... and to discharge. I've taken to putting "bleeders" on my big caps in JT experiments so I don't have to wait so long for them to get down to interesting voltage levels. A momentary contact pushbutton and a 1R or 10R in series, across the cap.

I've seen periods where the big caps will rise in voltage while powering the LED load. This is dielectric recovery, not energy from the circuit going back into the cap, and it happens most strongly just after a heavy discharge -- like by using the bleeder circuit -- and going back to normal discharge loads. The LEDs will shine brightly and the voltmeter on the cap will show a steady increase in voltage for a while. This can even be repeated several times with the supercaps I'm using, 10F @2.7V.

As far as tuning goes... it is theoretically possible to tune to a given frequency with arbitrary combos of caps and inductor values that satisfy the resonant tank formula, but I have found that there is a "balance" of sorts between capacitance and inductance that seems to work best. I don't know how exactly this optimum balance can be calculated. Maybe it is "pF ~= nH" or something like that. In any case I think the capacitors are more lossy than the inductors we usually play with, so a larger cap will waste more of the power in the tank than a larger inductor will. But the larger inductor will lose more by RF radiation than the large cap will.

The Ruslan thing: He has shown videos where he is actually inside the transmitter building of the FM radio station. I think he is probably a lot closer than 500m when he does his demonstrations. And there is much less fall-off in the near field, it goes more as 1/r rather than 1/r2.  I have also just last night completed a wireless power transmitter that could easily be concealed in a coat pocket with the transmitting loop around waist or shoulders, and could be powered by a small LiPo battery. This apparatus will light up the Electrosmog Harvester or other co-resonant circuits out in the middle of a desert far from any radio stations or other sources of power... as long as I don't let you search my clothing.

Getting power into and out of the pot core coil itself isn't as hard as it might seem... after all the core is connected to other circuitry. And suitable receiving antennae can be concealed relatively easily.

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

 ;)

If you have any JFETs handy... try the ConradElektro/magpwr 2sk170 circuit!

d3x0r

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #299 on: July 20, 2014, 11:59:28 PM »
Getting power into and out of the pot core coil itself isn't as hard as it might seem... after all the core is connected to other circuitry. And suitable receiving antennae can be concealed relatively easily.

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

 ;)

If you have any JFETs handy... try the ConradElektro/magpwr 2sk170 circuit!
But at 60Hz a suitable receiving antenna ?  quarter wavelength is 4,100,000 Feet :/ 


Ya I saw that mosfet version; was thinking of playing with that. ( http://www.overunity.com/13175/25mv-joule-thief-powered-by-peltier-merely-using-our-body-heat-free-energy-247/msg410419/#msg410419 )  I don't have any JFET..I think... just power mosfet; but I think that just changing the core winding ratios can overcome that... most of the fets I chose for low gate capacitance