EPIC WIN!!!!!!!!!!!!!!!! MUHAHAHHAHAHA GOOD RESULTS FOR $40 in parts!
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EPIC WIN!!!!!!!!!!!!!!!! MUHAHAHHAHAHA GOOD RESULTS FOR $40 in parts!
Last pt at 28' was CM I believe.
And thanks again for being willing to come out in the wet to meet me, I am not so sure I would want to meet some big long haired hippy like dude with a soldering iron and a crazed look in his eye.Quote:
Originally Posted by category4
Still want to test the blinder again once I change the CC unit for higher a current test . the fact that it did Jam give me hope others will be able to self upgrade their (out of warranty hardware)
As for the home made unit, going to pop it up to 2 MHZ and add the other leds. Its gonna be a fun run at the end of the month.
I am going to post on another thread and see if anyone else has dead or broken heads and see what can be made out of them. I still want to see if I can increase the detection of the blinder units and others
Anytime my schedule allows. looks like I'll be out of town for the next few weeks, but that's always subject to last minutes changes!!:eek:
Quote:
Originally Posted by Solion
The Traffipatrol is probably the easiest gun to jam... WITH jam codes. Your 2 KHz would have done it.
I have a feeling you are talking about theTraffipatrol XR?
Yeah , thats the one.
I am just so ramped up now to throw anything and everything at it. but first the marker lamps and we will see where we are .. hopefully on a day it isn't cold or nast or both.
YEEEEHAAAAA May I say!Quote:
Originally Posted by Solion
Fantastic!
I am an M40 carrier. I need to infect my Blinders with a course of good old fashioned ingenuity.
Quote:
Originally Posted by STiMULiYEEEEHAAAAA May I say!Quote:
Originally Posted by Solion
Fantastic!
I am an M40 carrier. I need to infect my Blinders with a course of good old fashioned ingenuity.
I got a few private messages on the power output of the leds at 90 KHZ
I was curious too so I hooked her back up
So here is a quick video of 90 KHZ in action , keep in mind this is is only 7.2 watts not the 75 watts the LI puts out ... However at 90 khz, you can now witness the full power of this fully function battle sta......ER ....lidar jammer
[ame=http://www.youtube.com/watch?v=aVIyfYu_u3E]YouTube - REC-00011.avi[/ame]
:hairfire:
what camera you're using?
I'll assume that's peak power, because if it was average power you probably would not be reading this. What is the average power? I won't pretend to know all of the ins and outs of optical power: I don't. But here's my take:Quote:
Originally Posted by Solion
The diode jammers that use the 75W SPL_PL90 diodes are transmitting a very low percentage of the time. Consider a PLIII: at 200pps it is transmitting one pulse every 5000000 nanoseconds. Say the jammer produces one jamming pulse for each of the gun's pulses. The jammer is transmitting only 0.0005% of the time. Although the peak power is 75 Watts, average power in this case is 375 Microwatts. Typical TV remotes are in the order of 1000 microwatts (if we are to believe LTI). So, even if a jammer doesn't have that great of timing and it takes the jammer multiple pulses to jam each of the laser gun's pulses, radiated power is still very low. These jammers are typically Class I or Class IM.
The old LE-10 patent suggested that they transmitted 7W peak power, and also suggested 2 Mhz (though I was told 4 MHz personally by a Lidatek engineer). At 2 MHz it is transmitting one pulse every 500ns. If each pulse is 25ns in duration, it would be transmitting 5% of the time. Average power would be 350000 microwatts, or 350 milliwatts. These were classified as Class III lasers.
You have 7.2 watts of power. At 90 Khz, that's one pulse every 11111 nanoseconds. If each pulse is 25ns in duration (with LED's it's most likely much longer!) you are transmitting .225% of the time. Average power would be around 16200 microwatts/16.2 milliwatts, at any rate several times that of the diode jammers. So, you're most likely already in the Class III zone. :eek: Please be careful!
Jim
http://crazy-jokes.com/pictures/blind-stickup.jpg
That gives a whole new meaning to the name "BLINDER"
The best way to calculate is if it is measured in watts for radiant flux and watts/steradian for radiant intensity, Ir Leds don't have a coherent beam like lasers do and falloff over distance is pretty seveare. So no real chance of cooking the eyeballs of people unless you are right up on itQuote:
Originally Posted by jimbonzzzI'll assume that's peak power, because if it was average power you probably would not be reading this. What is the average power? I won't pretend to know all of the ins and outs of optical power: I don't. But here's my take:Quote:
Originally Posted by Solion
You have 7.2 watts of power. At 90 Khz, that's one pulse every 11111 nanoseconds. If each pulse is 25ns in duration (with LED's it's most likely much longer!) you are transmitting .225% of the time. Average power would be around 16200 microwatts/16.2 milliwatts, at any rate several times that of the diode jammers. So, you're most likely already in the Class III zone. :eek: Please be careful!
Jim
Calculations for radiant flux are usually related to beams, However radiant power of a led must take in the division of the angle ( think cone shape) While an emitter may have 180mw/sr My angle of half intensity is 10deg.
But you are right ,you should be careful and I won't will be staring directly into at close range Best calcualtion here is my average output is between 3.4w- 4
Overall, however the effect of IR light is mostly heat. Unlike other wavelengths like UV that distroys biological structures . Infrared is much safer than visible light and has a lot less energy.
they use MASSIVE IR arrays for night filming of wildlife (on the order of 200watts) And IR led Flashlights all the way up to 4w are available anywhere . And millitary uses illuminators to 30w
SO no.... Im not going to put my eye out or anyone elses.
Hey it's as solid as sears
http://www.sears.com/shc/s/p_10153_1...0070921x00003a
The camera I use is a little webcam with the IR filter removed . works really well and easy to hook up to the lappy for stuff like this
x2 I was thinking the exact same thing, i was BLINDED just WATCHING THAT ON *VIDEO* HOLY CRAPQuote:
Originally Posted by STiMULi
The UL also throws jam codes, which if you are doing this brute style, you'll probably throw one.
But, as you said, this is a large step forward, especially for 40 bucks :)
But on the other hand, with visible light you can count on your blink reflex to limit your exposure. With IR, you don't have that luxury. :(Quote:
Originally Posted by Solion
True, but when people talk about IR/UV damage and blink reflex it is in relation to lasers and other coherent wavelengths of light, Now THATS dangerous.Quote:
Originally Posted by jimbonzzzBut on the other hand, with visible light you can count on your blink reflex to limit your exposure. With IR, you don't have that luxury. :(Quote:
Originally Posted by Solion
The most massive difference between an Ir led and a IR laser with collumnating lens is energy diffused vs energy as a beam. and that is where allot of the confusion lays in the arena of damage to the eye. If I had 500mw in an expanding cone (such in a led) you have to calculate the energy reaching the sensor or your eye by the angle of that cone. Rough calculation is at 500mw at 3 feet with 10deg led you would be getting less than .03% of that energy into your eye, at greater distances the falloff is dramatic
A laser keeps most of its energy over a long distances. so at 3 feet that same power is gonna fry a little dark spot on our retina even at 1/2 the power. hell it will do it 10 feet , 20 feet , 30 feet.
Really its safer than most people think. The class 3 laser tag on the LE-10 was all about the rated wattage of the laser diode and did not recognize the lens that was spreading that beam out.. and well , they need to have it for the guy who sticks his eye up against the lens.
That said , I will take my camera today and record the IR comming from my space heater... you think my IR leds are bright? . wait till you see this thing.
x2, lasers are concentrated and directed beams of light, unless, which I don't doubt with Solion, he makes the LED output brighter then the SUN, I don't think anyone needs to worry about being blinded :DQuote:
Originally Posted by SolionTrue, but when people talk about IR/UV damage and blink reflex it is in relation to lasers and other coherent wavelengths of light, Now THATS dangerous.Quote:
Originally Posted by jimbonzzzBut on the other hand, with visible light you can count on your blink reflex to limit your exposure. With IR, you don't have that luxury. :(Quote:
Originally Posted by Solion
The most massive difference between an Ir led and a IR laser with collumnating lens is energy diffused vs energy as a beam. and that is where allot of the confusion lays in the arena of damage to the eye. If I had 500mw in an expanding cone (such in a led) you have to calculate the energy reaching the sensor or your eye by the angle of that cone. Rough calculation is at 500mw at 3 feet with 10deg led you would be getting less than .03% of that energy into your eye, at greater distances the falloff is dramatic
A laser keeps most of its energy over a long distances. so at 3 feet that same power is gonna fry a little dark spot on our retina even at 1/2 the power. hell it will do it 10 feet , 20 feet , 30 feet.
Really its safer than most people think. The class 3 laser tag on the LE-10 was all about the rated wattage of the laser diode and did not recognize the lens that was spreading that beam out.. and well , they need to have it for the guy who sticks his eye up against the lens.
That said , I will take my camera today and record the IR comming from my space heater... you think my IR leds are bright? . wait till you see this thing.
But even then, I've stared at the sun, and eclipses a lot as a youth and despite what they say on TV, my eye sight is a perfect 20/20:eek:
Here is a great example of what I am talking about when we talk about diffused energy, And the frequency of that energy. IR is very safe untill you get it shoved into coherent beams. First,take a look a picture of my 2000W space heater under the table.
THEN look at the video. I don't think anyone has any fears of looking at their space heater, In fact this throws out so much IR that even blocking the lens with my finger, the image is grey from the IR passing through it
[ame]http://www.youtube.com/watch?v=kftZavnxrUE[/ame]
:hairfire:
I think it is great we ask these questions about safety because they do need to be asked, and through it we begin to understand a few things about how things work and how they don't.
ISn't science FUN! :D so the next question is this. if we can assure safety to the public and to ourselves. why not go for broke? Sufficient array of Leds (in the correct NM range) to blind the gun.
Well nothing really, except for power, and if you will throw a jam code or not. So lets talk about the first. Power...on average lets say we get a nice big PNP power transistor to flip with a lidar detector to fire an array of LED's how much would you need? well In amps to drive them about 10. about 4 watts minimum of Ir output should overwhelm the pulses from the gun. Could you do 20 - 30 - 100 , sure. but keep in mind the ammount of current you will need to switch and regulate.
Second, JAM codes... Sadly I don't have a Lidar gun , much less one that will throw a jam code. But IF we are not outputting a pulsed signal and just a constant ON will a gun see that as a jammer? or just a bright IR source.... Hmmmmmmm dunno , Only Cat4 can answer that one for me. Id say if he has a space heater to fire his gun at it and see if it pulls up a jam code. Just an idea in a long list of em
If you COULD jam with a solid on output, why not leave it on? .. well thats simple, you want a triggered on because the same system that jams the detector in the lidar gun will probly jam the detector in your laser/radar detector from light pollution (its why you cant see the stars at night in a city ) . and you want to know when you are being hit.
Why do I have a feeling the MIB or a hit squad is getting ready.....
A space heater is useless against a lidar.
Don't mix up "near infrared" (IR-A ; 700-1400nm) and "long infrared" (IR-C ; 3000-10000000nm). A photodiode (SI-pin diode) has 0 sensitivity in the IR-C spectrum.
You might be able to overwhelm a lidar with a non-pulsed IR source, but you will need a lot more power then 4 watt. You will probably need a very expensive, very dangerous and very power hungry cw ir laser. The receiver end of a lidar is designed to separate background noise (sunlight, xenon headlights etc.) from its short reflected ir pulses, and it does a very good job at it.
A lot less expensive than you might think. You can buy 1.5 million candlepower IR spotlights and floodlights in the 900-950 nm range for about $150 - $250. Its non-laser. Basically a spotlight designed to put a huge amount of candle power in the approximate range and an IR filter to block out any visible light leakage. It'll plug into a 12 v power source such as a cigarette lighter. I linked to a couple of them in a thread somewhere here on the site, to discuss the feasibility of using one to brute force jam.Quote:
Originally Posted by fulcrum
Quote:
Originally Posted by fulcrum
But the IR we care about is in the 904-905 nm area
X2 , the IR comming from a space heater is from about 780 to 980 nm how do I know this? I have a couple of high brightness 950's I was playing with at 100mw/sr and they were very very dim in comparison to the 890's on the same IR camera. there is a limit to the sensitivity of the ccd in the little camera.Quote:
Originally Posted by STiMULiQuote:
Originally Posted by fulcrum
But the IR we care about is in the 904-905 nm area
However I still hold to my claim that 4w as your minimum, and here are the numbers.
IR lasers in a lidargun have to comply with saftey standards as set by the US government. This compliance requires that all lasers fired from Lidar guns are "eye safe" or in terms set out by Class 1, Class 1M and Class 2 (however I am not sure if any Lidar guns now are class 2 or above. Professor?)
In short, Lidar output (even if they claim to have 50WATT modules) is very small. because the "on " times of that emitter are very very short. so what once was a mighty 50 watt that could burn flesh, melt steel is now about 50mw. and to be honest probly a little less than that. keep in mind I can buy a 300mw IR laser diode from ebay that I can light matches and cigarettes with (for a power comparison)
So lets take a look at why 4 watts could jam a lidar gun. as I said in a previous post we can ramp up the power quite abit on our side of things because we are not throwing our coherent focused beams of energy. So we are eye safe in that arena. But when I say 4 watts will jam, IS with the caveat of 4 watts of IR in the correct NM range to blind the detector in the gun.
When most people think of 4 watts, they think of the little 4 watt bulb used in a night light. "how could that JAM a gun ?" Well it cant, neither can your headlights because the IR slice of the spectrum of light being thrown out is so small. You may or may not have played with Prisims when you were in science class. but the basics of light breaks down to a rainbow of frequencys that make up white light , a 100watt bulb is only going to put out .0018w of the IR frequency needed to jam a lidar gun. But 4w of that same frequency would require a lightbulb the size of a van to produce it (in white light)
With me so far?
Back to the lidar gun. at 50 mw .. the gun has to be able to see its reflected pulses to calculate the change in distance over time to calculate speed. and this is where a little voodoo sets in. And another caveat, reflectivity.. Oh this is a tough one to quantify as every car is different, every paint is different , every reflector is different. How much power of the pulse is reflected back is in direct relation to the distance it can nail you at. And here is the kicker. the beams divergence over distance is pretty big., at 2000 feet it will cover your whole car and part of the car next to you.
So lets take a moment and ask. Under Ideal conditions, if you mounted a mirror to the front of your car and shot it at lets say 1000 feet. how much energy would you get back to the apeture of the gun.. well if you said 50mw, wrong .. 10 mw , wrong ..2 mw still wrong ... less? I hate guessstimation of maths, without knowing some specifics on a lidar gun , apeture size , divergence ect I will throw out a number. somewhere on the order of .01mw,
Why so low? Well remember our old friend divergence, the laser pulse comming from the gun at 2000 feet is going to be about 6 feet in dia, we will say 3 feet at 1000, even if you had a mirror, the reflected pulse at 1000 feet has to make that same return of a 1000 feet back to you. the beam continues to spread into a 6 foot cone. If you had a 6 foot lens on the front of the lidar gun, I suppose you could focus allot of the energy back into the gun. , That would be fun to see :lol:
but not practical. you are only going to get a tiny tiny slice of the pie back into the Gun with the 2 inch dia objective lens. These numbers change the closer you get , as the cone shrinks. But still you will loose quite abit of power even at short distances.
So with this in mind, how can 4 watts do the trick. Well , it depends on the car and your reflectivity index. 4 watts of 900nm indeed may not work for a car with a silver paintjob or a ton of chrome on the front. Or trucks with large vertical surfaces but for cars with lower front ends and dark in color it may be enough .
Boy did this turn into a long winded MR SCIENCE . but I think peoples understanding of Light and its properties will be helpful to push forward the Hobby of home built jamming.
I'm not aware of any either...Quote:
Originally Posted by Solion
< So lets take a moment and ask. Under Ideal conditions, if you mounted a mirror to the front of your car and shot it at lets say 1000 feet. how much energy would you get back to the apeture of the gun.. well if you said 50mw, wrong .. 10 mw , wrong ..2 mw still wrong ... less? I hate guessstimation of maths, without knowing some specifics on a lidar gun , apeture size , divergence ect I will throw out a number. somewhere on the order of .01mw >
Great resume Solion !
When I compare the output of my Osprey versus a tv remote ,
thru a digital cam set 2 inches form the emitter lens ,
the relative brighness is like 1 to 20 ,
I guess the secret of the sensitivity of the gun is the lens.
It is like a cat"s eye in the dark .
Well sensor technology is some neat stuff. but the real trick is the fact that the lidar guns sensor is set to receive a very very small fraction of IR bandwidth at huge sensitivity. and that is its Achilles heel to overpowering it. To see some really tiny returns that little sensor has got to be incredibly sensitive. Probly on the order of 40,000 times more sensitive than the human eye.Quote:
Originally Posted by Eloi
Sorry, but you are making several mistakes.Quote:
Originally Posted by SolionX2 , the IR comming from a space heater is from about 780 to 980 nm how do I know this? I have a couple of high brightness 950's I was playing with at 100mw/sr and they were very very dim in comparison to the 890's on the same IR camera. there is a limit to the sensitivity of the ccd in the little camera.Quote:
Originally Posted by STiMULiQuote:
Originally Posted by fulcrum
But the IR we care about is in the 904-905 nm area
However I still hold to my claim that 4w as your minimum, and here are the numbers.
IR lasers in a lidargun have to comply with saftey standards as set by the US government. This compliance requires that all lasers fired from Lidar guns are "eye safe" or in terms set out by Class 1, Class 1M and Class 2 (however I am not sure if any Lidar guns now are class 2 or above. Professor?)
In short, Lidar output (even if they claim to have 50WATT modules) is very small. because the "on " times of that emitter are very very short. so what once was a mighty 50 watt that could burn flesh, melt steel is now about 50mw. and to be honest probly a little less than that. keep in mind I can buy a 300mw IR laser diode from ebay that I can light matches and cigarettes with (for a power comparison)
So lets take a look at why 4 watts could jam a lidar gun. as I said in a previous post we can ramp up the power quite abit on our side of things because we are not throwing our coherent focused beams of energy. So we are eye safe in that arena. But when I say 4 watts will jam, IS with the caveat of 4 watts of IR in the correct NM range to blind the detector in the gun.
When most people think of 4 watts, they think of the little 4 watt bulb used in a night light. "how could that JAM a gun ?" Well it cant, neither can your headlights because the IR slice of the spectrum of light being thrown out is so small. You may or may not have played with Prisims when you were in science class. but the basics of light breaks down to a rainbow of frequencys that make up white light , a 100watt bulb is only going to put out .0018w of the IR frequency needed to jam a lidar gun. But 4w of that same frequency would require a lightbulb the size of a van to produce it (in white light)
With me so far?
Back to the lidar gun. at 50 mw .. the gun has to be able to see its reflected pulses to calculate the change in distance over time to calculate speed. and this is where a little voodoo sets in. And another caveat, reflectivity.. Oh this is a tough one to quantify as every car is different, every paint is different , every reflector is different. How much power of the pulse is reflected back is in direct relation to the distance it can nail you at. And here is the kicker. the beams divergence over distance is pretty big., at 2000 feet it will cover your whole car and part of the car next to you.
So lets take a moment and ask. Under Ideal conditions, if you mounted a mirror to the front of your car and shot it at lets say 1000 feet. how much energy would you get back to the apeture of the gun.. well if you said 50mw, wrong .. 10 mw , wrong ..2 mw still wrong ... less? I hate guessstimation of maths, without knowing some specifics on a lidar gun , apeture size , divergence ect I will throw out a number. somewhere on the order of .01mw,
Why so low? Well remember our old friend divergence, the laser pulse comming from the gun at 2000 feet is going to be about 6 feet in dia, we will say 3 feet at 1000, even if you had a mirror, the reflected pulse at 1000 feet has to make that same return of a 1000 feet back to you. the beam continues to spread into a 6 foot cone. If you had a 6 foot lens on the front of the lidar gun, I suppose you could focus allot of the energy back into the gun. , That would be fun to see :lol:
but not practical. you are only going to get a tiny tiny slice of the pie back into the Gun with the 2 inch dia objective lens. These numbers change the closer you get , as the cone shrinks. But still you will loose quite abit of power even at short distances.
So with this in mind, how can 4 watts do the trick. Well , it depends on the car and your reflectivity index. 4 watts of 900nm indeed may not work for a car with a silver paintjob or a ton of chrome on the front. Or trucks with large vertical surfaces but for cars with lower front ends and dark in color it may be enough .
Boy did this turn into a long winded MR SCIENCE . but I think peoples understanding of Light and its properties will be helpful to push forward the Hobby of home built jamming.
1) Yes I believe you, when you say that the heater is brighter in your camera then the LEDs. Some (relative) very small part of the radiation is in the near-IR region, and the camera sees a pretty wide part of that spectrum. (From visible to far into the near IR) Because these heaters have such high power, the (to the camera) visible part of the total output of that heater is still brighter then the LED.
But it is totally unpractical to flood (or blind) a lasergun, because a heater is an extremely inefficient near IR source. My guess (and it is really just a guess) is that less then 1% of the heater output lies within the spectrum you need for jamming. So 99% or more of the heater output lies not within the 780-980nm as you suggest.
2) The reflected energy from a lasergun pointed at a license plate at 600ft as seen from the 2" receiver lens by that lasergun is a much more then that of a 4 watt laser mounted on a car at 600ft.
There is one exception to this rule: The laser on the car directly beams into the receiver lens of that lasergun.
And that is the problem here. Any narrow focussed laser mounted on a car will point in the wrong direction, and will simply miss the lasergun. To solve this problem, the laserbeam has to be diverging. (Maybe 20 degrees?) Now make the calculation. A 20 deg diverging laserbeam at a distance of 600ft will project a circle of IR light with a radious of around 100ft ((sin(20 deg) * 600ft)/2) The area of that circle is 31400 sq feet. The area of a 2" lens is only 0.022 sq feet. The lasergun will "see" less then 1/1000000 of the total radiated ir laser light..............
Now I have to simplify things:
- A lasergun at 600ft will project a circle with a 1ft radius.
- The area of that circle is 3.141 sq feet.
- Assume the area of a license plate is 0.25 sq feet
- Then 8% of the laser energy hits the license plate
- Assume the license plate retro-reflects 25% of that energy to the source.
- In this case the lasergun "sees" 2% of its reflected pulse. (Assume the rest of the car doesn't reflect anything)
0.02 is 20000 times more then 0.000001
The lasergun laser is 20+ watt. Do you still think that a 4watt cw laser on the car is enough?
These simple calculations show me that passive flooding of a lasergun is unpractical and dangerous because of the power you will need for it to be effective.
Back to the heater................
Now try flooding with a heater at 600ft you'll need to install a BIG heater on the car. (maybe 20000x100x20 = 40000 kWatt)
3) You're mixing up pulse power and average power. To hide a 20W pulse you need 20W cw. And even that is to low, because light (fotons) add up, and (this is over-simplified) you will end up with 20W spikes on top of a 20W noise level. Again this can be filtered away as background noise, and the gun will still "see" the pulses.
By the way: Things become a lot easier without front license plates.
I think I will take each argument on order and try and quantify my statements,
First what you said:
Quote :Yes I believe you, when you say that the heater is brighter in your camera then the LEDs. Some (relative) very small part of the radiation is in the near-IR region, and the camera sees a pretty wide part of that spectrum. (From visible to far into the near IR) Because these heaters have such high power, the (to the camera) visible part of the total output of that heater is still brighter then the LED.
But it is totally unpractical to flood (or blind) a lasergun, because a heater is an extremely inefficient near IR source. My guess (and it is really just a guess) is that less then 1% of the heater output lies within the spectrum you need for jamming. So 99% or more of the heater output lies not within the 780-980nm as you suggest.
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My suggestion about the heater had really nothing to do with using it as a jamming source. But more to alleviate the fears that my array or any array of
high brightness LED's (not lasers) in the 900 to 905 as being a source of power will not do eye damage. Which is what quite a few people here had worries about. I was using it as a tool to show that high levels of IR come from various sources in our world and we are not walking around with canes.
For gods sake, I am not suggesting everyone stick space heaters on their grills :lol:
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Your quote:
QUOTE :2) The reflected energy from a lasergun pointed at a license plate at 600ft as seen from the 2" receiver lens by that lasergun is a much more then that of a 4 watt laser mounted on a car at 600ft.
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Me: DID I say LASER? .. if you re-read I said IR Led at 10deg. Important difference here. And I think I did mention reflectivity as being an important factor. that IMHO 4 w was your MINIMUM not that it would jam Lidar if you have a massive reflector on your car.
As for your statement of brightness., I would like to take you up on that. have you SEEN a 4w IR LED with an IR camera? today and just for you I will take another quick video of a single 4W 850nm led. I think you and everyone will be pretty shocked. Also as a scale of brightness take a look at this video link. in it he shows the various power outputs of jammer heads. but in it as well you can see the actual rectangle beam coming from the gun. and how little in comparison it puts out to the heads.
http://www.donspc.com/vidpics/IRcombo.wmv
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Your statement:
Now I have to simplify things:
- A lasergun at 600ft will project a circle with a 1ft radius.
Me: Well depends on the gun but most agree at 500ft is 18inches
- The area of that circle is 3.141 sq feet.
- Assume the area of a license plate is 0.25 sq feet
Me: with you so far
- Then 8% of the laser energy hits the license plate
Me: In a perfect world in a vacuum on a tripod, Okay I am there
- Assume the license plate retro-reflects 25% of that energy to the source.
Me: this is where you begin to loose me. because from where I am standing its going to be less than that. but okay.
- In this case the lasergun "sees" 2% of its reflected pulse. (Assume the rest of the car doesn't reflect anything)
And ..... you lost me.. okay like I mentioned before while coherent (laser) light does go farther, divergence is an issue. you are not getting the reflected energy from the 600ft/12 inch cone. you are getting the energy from a 1200 foot/24 inch one. You don't get that back for free.
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The lasergun laser is 20+ watt. Do you still think that a 4watt cw laser on the car is enough?
Again, I think this a misunderstanding of the real power output of a lidar gun. its not 20 watts, its maybe 50mw I can assure you at no time are you getting that much energy. its a class1 device for a reason. the video pretty much proves how bright the reflected energy from a lidar gun is. But give an ahour or so . let me show you 4w.
As promised here is a video of an 850 nm luxon star 4 watt led. I had to do this inside as the weather is for shait today. and I dont want it to rain on my lappy
[ame=http://www.youtube.com/watch?v=jCEDlq4tjGs]YouTube - REC 00015[/ame]
I think people need to understand that there is a scale where maximum saturation occurs. first is in reflectivity and second is the sensor of the gun.
the Guns sensor has an upper limit to how much current it can pass. it is not infinite
so you can saturate that sensor to a point it will not see anything but what you want it to see.
But I do have one admission I want to make here . that led in the video you just looked at .... its not 4 w ... its 2 ....
You're totally wrong about the damage of infrared light to eyes. You can very easily damage your eyes with an infrared 3W led, and the scary thing is that you won't even know it. IR is much more dangerous than normal light because our retinas do not contract when exposed to it. We also don't squint. The IR heats up the retina and causes permanent damage. The problem is that this damage manifests itself in small blind spots that our brain adapts to and tunes out. There very well may be "holes" in your vision that you aren't even aware of.
This has been documented hundreds of times by medical journals, scientists, etc.
Sorry to rain on your parade.
Okay now, first thing I would like to do is show your work. and show me how diffused IR ... NOT LASER .. Diffused IR at 3w burns peoples retenas at distances over 1 foot.Quote:
Originally Posted by computerpro3
Or I am calling you a troll
I am calling you out on such a statement. because it is blndingly silly. While IR LASERS at 3 w will fry a hole in your retina 3 watts of diffused IR from an IR Led is not going to.. SIGH . Lets take a look at a few things here. by your own statement.. that 2000 watt heater throwing massive IR has blinded me.
Every security camera is blinding people. the 4w, 6w 10w IR IR flashlights
have punched holes into your retina. THE SUNLIGHT reflecting off a bit of chrome has punched holes... gawds
Show your work , Show me the scientific evidence of your claim
Show me the energy levels of those claims
Show me medical evidence of your claims
WHY? ... I will do this one more time, just for you. :banghead:
People have this weird idea about energy. The problem comes mostly from a misunderstanding of Physics or they spell it Fizziks
Why is 3w of diffused Ir not going to FRY YOUR EYES. well first thing we have to understand is that stated 3watts IS NOT going into your EYES! Now you can't put your eyeball on the lens of the emitter. But try and understand that Diffused IR from a LED is projected in a cone. just like any other source of light in other wavelengths.
As this cone spreads out the total energy has to be divided by the angle of that cone. NOW you have to figure out the amount of energy you can capture with the objective lens, (we will say 10mm for the human eye)
Do you see the light now? well no you cant .. its Infrared .. but that gets into the last part of beating this dead horse .. :026:
Wavelength....Do you understand the difference between the energy carrying ability of UV Vs IR ? .Its usually measured in eV or energy per photon.. UV B
lets say in 315 nm–280 nm has an eV of 3.94–4.43 eV IR 750nm to 900 nm has an eV of 1.65 to 1.49 ..
Do you get it? .. :rolleyes:
Yes there are Osha standards for steel and ceramic workers to protect their eyes, but they litterally are having to deal with hundreds of thousands of watts of IR and IR into much higher frequencies. For hours and hours daily
You Do realize that on a sunny day we get over 500 watts of IR per METER.. IMm BLIND IM BLIND!
Stop the scare and show your work. This is the last time I will address this that the 4w from my LED jammer running for a max of a couple of minutes are NOT GOING TO PUNCH HOLES IN YOUR EYES Arrrrggghh!
:badputer:
Am I the only 1 who don't know that the h@ll they are talking about? Maybe this is the reason I failed engineering class.
dont worry they got off topic a bit...Quote:
Originally Posted by DrCoke
Yeah , sorry about that everyone.
Now that is cleared up...YA science,
Lets talk about the HMLJ ... actually decided today to call it the HMLT Spyder P2.
(home made lidar transponder spyder(8 heads 4 front 4 back) prototype 2)
Today I started in on the second set of heads for the headlights. these will be round and will fit into the turn signal lamp housing. turn lamps will work as per normal since it is a doughnut shaped assembly that surrounds the original lamp.
Tested for the ammount of loss through the amber lens using the 2 watt Led in the previous video. the answer is ... almost none, upon closer inspection with the IR camera I discovered that the polycarbonate of that lense looks nearly transparent in the Near Ir.
However , do to refraction the whole friggin headlight housing is one big glowy bright mass of IR now. I think my headlight shots are well and truly protected to be honest.. but wont know till testing day.
Photos to come soon. Or untill it freaking warms up.. went out this evening to put my headlight back on in the cold... at night .. gods that sucked.
I'm looking forward to your testing results! Appreciate the work you're putting into this and sharing with the community.
You really don't get it. Do you???Quote:
Originally Posted by Solion
You can buy a 75w Osram pulsed laser diode for less than 50$.
It will output 75w PULSED power in very short pulses of a few ns per pulse. If you make the pulses to long, the diode will be destroyed. If you pulse it with a too high frequency it will also burn out.
The average power output of this laser is extremely low, and (in general) not dangerous. But this little laser diode will be very visible/detectable close to a very dangerous cw laser with thousands of times higher average output power costing more than 2000$.
Why do you think you can see a xenon strobe light flashing next to a 500watt halogen floodlight? The average power of the halogen light is much higher than the average power of the strobe light.
Why do you think you can hear the sound of a firecracker going of close to a passing freight train? There is so much more (sound) energy from the freight train. Again the pulse power of the firecracker is much higher than the average power of the freight train.
Why do you think a laser gun works so good in bright daylight? (Read your own post about the amount of near IR in sunlight)
The other effect that works against passive blinding is the fact that light output is cumulative. The laser pulses will be added to the light level of the constant on source. These pulses can be separated from the background noise using specialized photodiode based receivers. (As used in any lasergun)
Read something about photodiode (pulse) receivers, especially about handling high ambient light levels and/or separating ns pulses. Whole books have been written about these subjects.
Forget passive jamming with LED's it simply doesn't work with modern laser guns. You need a pulsed source. The switch on speed to full power has to be within 1-50 ns, the switch off time is not critical. A pulse frequency of a few 1000 Hz will not work with most laser guns. (Of the 4 laser guns I own, only the European LaserPatrol can be jammed this way) If you want to jam other guns, you need pulse frequencies approaching 1MHz or even more)
Again, passive jamming normally doesn't work. I tried it with a few hundred 880nm HP infrared LEDs. I still have about 1000 of them here. Passive jamming only works a little bit on bad reflecting targets. The type of laser gun also matters.
By the way, if you want to measure and or compare brightness of different infrared sources (including laserguns, LED's etc) then a video camera is a very bad tool for it. Remove the IR filter of a digital photocamera, and make longer exposures (in the dark) without clipping the image. You can use photoshop etc. to get the bit values of the pixels. As light is cumulative, it will give you much better information.
Okay well two things today, First the newest of the switching units I Just finished.Quote:
Originally Posted by fulcrumYou really don't get it. Do you???Quote:
Originally Posted by Solion
You can buy a 75w Osram pulsed laser diode for less than 50$.
It will output 75w PULSED power in very short pulses of a few ns per pulse. If you make the pulses to long, the diode will be destroyed. If you pulse it with a too high frequency it will also burn out.
See photos below. this one is 12ns Tf/Tr and will be used to run the other sets of diodes.
Second is to address fulcrums statements here and set a couple thing straight about what I am doing.
If I was trying to build a clone of a Blinder or LI, Let me say emphatically That I could. would it take time, Yes .. would it be something anyone could build? Not a chance in hell. This was to see what could be built for under 50.00 and could such a device actually jam anything And the answer is yes. I managed with 40.00 to Jam a PLIII to 28 feet consistently CM and 128 feet on a headlight shot. Will these sorts of numbers hold up on other guns? Well at the end of the month we will all find out for sure. Would love to test again sooner. but I will take what I can get.
But lets take a look at the analogy's Fulcrum has stated here.
Quote : Why do you think you can hear the sound of a firecracker going of close to a passing freight train? There is so much more (sound) energy from the freight train. Again the pulse power of the firecracker is much higher than the average power of the freight train.
ME: Well, How much of the sound created by the freight train is in the same frequency range created by the firecracker? How about a train full of firecrackers! can you honestly tell me you will pick out the one you set off? this sort of thought experiment only works if your comparison is apples to apples and not apples to cucumbers..
Quote: Why do you think you can see a xenon strobe light flashing next to a 500watt halogen floodlight? The average power of the halogen light is much higher than the average power of the strobe light.
ME : Again with the apples and cumbers. lets take that and flip it on its head how about an massive strobe light putting out 90khz and you set the little one in front of it. You are going to be able to tell the difference?
Quote: Again, passive jamming normally doesn't work. I tried it with a few hundred 880nm HP infrared LEDs. I still have about 1000 of them here. Passive jamming only works a little bit on bad reflecting targets. The type of laser gun also matters.
ME: Well we can agree that 880nm Leds don't work for brute jamming. I tried them in my first test to a resounding utter fail. Then I went to the Varshay 890's and got 28foot jam on PLIII
QUOTE: Forget passive jamming with LED's it simply doesn't work with modern laser guns. You need a pulsed source. The switch on speed to full power has to be within 1-50 ns, the switch off time is not critical. A pulse frequency of a few 1000 Hz will not work with most laser guns. (Of the 4 laser guns I own, only the European LaserPatrol can be jammed this way)
ME: Did you even read through the whole build so far?...egads , let me help you .. here are the Vishay Leds I am using now with success 30ns Tr/Tf
http://www.vishay.com/docs/81313/tshf5210.pdf
Quote: The other effect that works against passive blinding is the fact that light output is cumulative. The laser pulses will be added to the light level of the constant on source. These pulses can be separated from the background noise using specialized photodiode based receivers. (As used in any lasergun)
ME: Okay this is just flat out wrong. I don't know where you got this information but lets look at the statement here, You are suggesting the light from 2 different emission points traveling in opposite directions are going to accumulate.. That the light traveling from your gun to the LED's is going to have an additive effect vs a light pollution effect. I suppose you can see the milky way in the middle of a city as well.
QUOTE :Why do you think a laser gun works so good in bright daylight? (Read your own post about the amount of near IR in sunlight)
ME: that statement was to put to bed the fear mongering idea that my IR leds were going to melt peoples eyeballs like raiders of the lost ark. But your statement was to use mine about power to prove your point?. NO, 500 watts per square meter from the sun will not cause problems because the frequency range the lidar gun SEES is a tiny slice of that. in like .023 watts... arrrgghhhhh!
ME: EGHH I have a headache in my spleen now , for the sake of science and our viewing audience let me explain why your statement has a few massive holes in it . some thought experiments for a moment. And why a passive jammer can work.
First lets talk about light, You cant actually see light untill it strikes something to illuminate it. or excites a material (like in your retina) to turn it into signals for your brain. So how we live most of our lives with light is seeing reflected light off of objects. Or exciting things like phosphorous.
If you take a laser and shine it at a car bumper, the reflected light is what you see. same for a lidar gun. the reflected light is how it determines distance. There is nothing magical about pulses. reflected energy is reflected energy. so at a set distance you will get X amount of MW to the receiver of the gun.
With me so far?, Okay. SO lets take a couple of handfuls of IR LEDs and throw it into the equasion. The amount of reflected light from the lidar gun remains the same (except in cases of emmitive saturation) from your bumper You don't get any more light to help you. My leds are not helping your laser. The best you can do is try and detect the DIFFERENCE between the levels. However , if you are throwing out enough IR what happens is that the signal gets lost in the noise. Pulsed or not. you have saturated to the highest level of the sensors ability to detect the tiny tiny changes. But you DO have to have enough to do it< And I do for the PLIII and I will have more.
what it depends on is the reflectivity (there is that word again ) of the item you are shooting.
Lidar sensors, gated or not have a maximum sensitivty and a maximum output. take a look at typical IR sensor PDF. http://catalog.osram-os.com/media/_e...00043391_0.pdf
There is no such thing as a sensor with infinite sensitivity.
At a distance light blooms into one big blob. you can look at cars comming down the road and see how the radiant cones comming from their headlights merge into one another untill they get close enough to be able to tell them apart. This effect at a distance works to cover a large portion of the car. where as the power continues to keep going up the closer I get to the gun.
Now then. I am going to continue with the build and test it against all of Cat4's guns. I will be testing with both Pulsed and NON pulsed sources to drive the leds. If it works in NON pulsed with the margin of error in comparison to other Jammers then I have changed jamming forever. If it works with the 2mhz driver unit again within the margins of normal units, Then I have built the cheapest effective jammer in the world.
WIN WIN , it already jams the PLIII. So the hall is rented, the orchestra engaged .. lets see if I can dance.
For what it's worth, the M20/40 line of Blinders used 880 nm LEDs and jammed the PLIII pretty well. They have since improved their LEDs (probably got something closer to 904).
Since I have the M40 any step forward is real progress. From what I understand the M40 (especially on my car with 4 heads in front on a Subaru Impreza WRX STi) will do the trick in my area but I would much rather have the HMLT Spyder P2 with some of the transmitters in the HLs.
I would bet from what I am learning from Solion I could move 2 heads to the rear and the have front and rear SNAGS (Speed Not Available at Gun) = Current JT/FG [Avoiding the use of the character "j" for obvious reasons]
Where can I get tickets to the Dance?
You will find my response in bold-blue....
Quote : Why do you think you can hear the sound of a firecracker going of close to a passing freight train? There is so much more (sound) energy from the freight train. Again the pulse power of the firecracker is much higher than the average power of the freight train.
YOU: Well, How much of the sound created by the freight train is in the same frequency range created by the firecracker? How about a train full of firecrackers! can you honestly tell me you will pick out the one you set off? this sort of thought experiment only works if your comparison is apples to apples and not apples to cucumbers..
The anology with light on average and peak power fully applies, except for the fact that sound is not really cumulative. Make a recording of this example and view it in a wave editor. You will see exactly what is happening.
Quote: Why do you think you can see a xenon strobe light flashing next to a 500watt halogen floodlight? The average power of the halogen light is much higher than the average power of the strobe light.
YOU: Again with the apples and cumbers. lets take that and flip it on its head how about an massive strobe light putting out 90khz and you set the little one in front of it. You are going to be able to tell the difference?
I don't know why you ask this, but yes you will be able to tell the difference:
a) If the pulse frequency of the small one is different than the massive one you can seperate the signals by first sampling the combined signals, and then look at the frequency/amplitude spectrum by using filtering techniques like bandpass or fourier analysis.
b) If the pulse frequencies are the same and 100% in sync, you can detect the small one by looking at the amplitude of the combined signals. (Analog threshold filtering, yes light works cumulative)
Going back to your initial reply. Trying to hide a stobelight in a flood of 'normal' light is an almost perfect and understandable representation of what you are trying to do. The question in your reply only blurs the subject.
Quote: Again, passive jamming normally doesn't work. I tried it with a few hundred 880nm HP infrared LEDs. I still have about 1000 of them here. Passive jamming only works a little bit on bad reflecting targets. The type of laser gun also matters.
YOU: Well we can agree that 880nm Leds don't work. I tried them in my first test to a resounding utter fail. Then I went to the Varshay 890's and got 28foot jam on PLIII
Depends on the lasergun and more specifically on the filter installed between the lens and photodiode. If these are the simple low pass type (like the one you removed from your video camera) then 880nm might work just as good as 905nm or 950nm. If the gun has a sharp narrowband filter, then the wavelength of the jammer LED or laser becomes critical, and it should match that of the lasergun or it will be blocked by its filter. I personally have experience with 2 guns that can be jammed perfectly with a standard 880nm or 950nm LED. (LaserPatrol and PLIII)
Test again on a modern LTI or LaserAtlanta........... The PLIII is extremely easy to jam compared to many other guns. The good old days when you could even jam a gun with bright headlights are really over.
QUOTE: Forget passive jamming with LED's it simply doesn't work with modern laser guns. You need a pulsed source. The switch on speed to full power has to be within 1-50 ns, the switch off time is not critical. A pulse frequency of a few 1000 Hz will not work with most laser guns. (Of the 4 laser guns I own, only the European LaserPatrol can be jammed this way)
YOU: Did you even read through the whole build so far?...egads , let me help you .. here are the Varshay Leds I am using now with success 30ns Tr/Tf
http://www.vishay.com/docs/81313/tshf5210.pdf
Nice powerfull and fast LED, but you will never be able to switch them that fast with your current design. (Read some of the older posts) To reach that switching speed you also need a very well designed driver circuit.
Quote: The other effect that works against passive blinding is the fact that light output is cumulative. The laser pulses will be added to the light level of the constant on source. These pulses can be separated from the background noise using specialized photodiode based receivers. (As used in any lasergun)
YOU: Okay this is just flat out wrong. I don't know where you got this information but lets look at the statement here, You are suggesting the light from 2 different emission points traveling in opposite directions are going to accumulate.. That the light traveling from your gun to the LED's is going to have an additive effect vs a light pollution effect. I suppose you can see the milky way in the middle of a city as well.
Do you really think that???? Did you do any research on the behaviour of light? Light is cumulative. If you point a lasergun on a car with a jammer, then the light received by the lasergun is an addition of its reflected light and the direct light of the jammer.
Light is cumulative.... Why are you using multiple LEDs???? Yes, because the total output of your jammer is the addition of the output of the individual LEDs. If you point 2 flashlights or 2 LEDs or 2 lasers at the same spot on the wall, that spot will be brighter with 2 lightsources than with only one. It is as simple as that......
And to prove my point further; Yes indeed! you can take pretty nice pictures of faint astronomical objects in light polluted city skies. It is a standard technique used in astro photography using CCD camera's. For example you take 10 pictures of the same region of the sky, you make sure these pictures are not overexposed (clipped) by the lightpolution. The next step is aligning the images and then totalling the value of each pixel of the 10 aligned frames you have in to a new frame. What will happen is that the noise (light pollution) information which has a random character adds up differently in each picture, but the data of object your interested is (more or less) the same in each picture. You will end up with a resulting image that has a greatly enhance signal to noise ration. You then substract a fixed value from each pixel in the resulting image to remove the light pollution part, and then expand the contrast. Et voila a faint astronomical object photographed even in a light polluted night sky.
Astrophotography happens to be one of my hobbies, don't tell me light is not cumulative, you are so 100% totally wrong on this matter.
Maybe you don't believe me just read this http://www.astropix.com/HTML/J_DIGIT/COMPEXP1.HTM or many other articles on the same subject.
YOU: First lets talk about light, You cant actually see light untill it strikes something to illuminate it. or excites a material (like in your retina) to turn it into signals for your brain. So how we live most of our lives with light is seeing reflected light off of objects. Or exciting things like phosphorous.
If you take a laser and shine it at a car bumper, the reflected light is what you see. same for a lidar gun. the reflected light is how it determines distance. There is nothing magical about pulses. reflected energy is reflected energy. so at a set distance you will get X amount of MW to the receiver of the gun.
Just to get things clear: The amount of reflected light is not how a lasergun measures range and/or speed. The amount of reflected light is used by some laserguns to adjust the bias of its photodiode to make the noise filtering more effective. (In other words setting a threshold level to isolate the reflected laserpulses from ambiant noise or light from a passive jammer)
With me so far?, Okay. SO lets take a couple of handfuls of IR LEDs and throw it into the equasion. The amount of reflected light from the lidar gun remains the same (except in cases of emmitive saturation) from your bumper You don't get any more light to help you. My leds are not helping your laser. The best you can do is try and detect the DIFFERENCE between the levels. However , if you are throwing out enough IR what happens is that the signal gets lost in the noise. Pulsed or not. you have saturated to the highest level of the sensors ability to detect the tiny tiny changes. But you DO have to have enough to do it< And I do for the PLIII and I will have more.
what it depends on is the reflectivity (there is that word again ) of the item you are shooting.
Lidar sensors, gated or not have a maximum sensitivty and a maximum output. take a look at typical IR sensor PDF. http://catalog.osram-os.com/media/_e...00043391_0.pdf
There is no such thing as a sensor with infinite sensitivity.
I would love to have a discussion on photodiode based pulse detectors, but you should first research the subject before writing about it. If you don't understand or agree on even the most basic principles on light, then a discussion about the subject is a waste of time.
YOU: At a distance light blooms into one big blob. you can look at cars comming down the road and see how the radiant cones comming from their headlights merge into one another untill they get close enough to be able to tell them apart. This effect at a distance works to cover a large portion of the car. where as the power continues to keep going up the closer I get to the gun.
And your point is?
YOU: Now then. I am going to continue with the build and test it against all of Cat4's guns. I will be testing with both Pulsed and NON pulsed sources to drive the leds. If it works in NON pulsed with the margin of error in comparison to other Jammers then I have changed jamming forever. If it works with the 2mhz driver unit again within the margins of normal units, Then I have built the cheapest effective jammer in the world.
WIN WIN , it already jams the PLIII. So the hall is rented, the orchestra engaged .. lets see if I can dance.
You're right on this one. Try jamming other guns first before you start to dance..........
why does everything have to end up in a pissing contest. its not about who is smarter but about the journey. good luck - hope to see the results soon.