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78 Comments
- OIF2_IFTE, on 10/12/2007, -0/+3now I havent build one from this component list yet, but here is a bit of a parts list for the construction of your MIRT.
componet list and part numbers
http://mouser.com/
Description: Schematic designator: Part Number: Price Each:
(2) 100K Resistors R2 & R4 660-CF1/2L104J $0.05
1K Resistor R3 660-CF1/2L102J $0.05
Controller ICNE555 IC1 512-LM555CM $0.33
500K Multiturn Potentiometer R1 652-3006P-1-504 $1.55
2N2222 Transistor (IR Driver) Q1 511-2N2222A $0.86
2N3055 Transistor (IR Driver) Q2 511-2N3055 $1.68
.1uF Ceramic Capacitor C2 140-50Q9-104Z $0.26
.47 uF Electrolytic Capacitor C1 140-MLRL50V.47 $0.08
www.bgmicro.com
Description: Part Number: Price Each:
High Power IR Array LED1007 $12.95
www.radioshack.com
Description: Part Number: Price Each:
8-Pin Retention Contact 276-1995 $0.69
PC Board 276-159 $2.29
Cigarette Lighter Adapter 270-1509 $3.99
I didnt get this list from i-hacked, but i spent a while refrencing the best parts i could find from mouser.com, radioshack.com and bgmicro.com. - silvershadow21, on 03/14/2008, -0/+2You're never going to read this, and I'm not sure why I'm even posting this, but it would be 18845 ohms. I was just looking through here to scrounge up any more info about it and I recently calculated it myself.
- kevincadogan, on 10/12/2007, -0/+2did anyone get the part #'s from mouser.com???
- toolwerx, on 10/12/2007, -0/+2If anyone happens to have the part numbers for mouser.com please post.
thanx in advance - xcomm, on 10/12/2007, -0/+2I read a little more info if any one has built this... if you change the rate to 14Hz you will have a higher priority.
“Low Priority� is generally considered to be 10 hertz (10 flashes-per-second) while “High Priority� is 14 hertz. The MIRT is only availabl in “HIGH PRIORITY� 14 hertz. - TheHyena, on 11/01/2007, -0/+1yeah, I think it was just the camera I was using made it look red... and make sure that its truly solid by going frame by frame and that you have a 30 fps camera... or make sure the fps is fast enough and that you have a number so that you can calculate the hertz. what are you pushing the board down on? I believe that mine is fully functional but the frequency is off, and since i don't have my own camera, and the person I was borrowing one from is now in New Zealand... work has kinda stalled for now. if any of you are in the denver area and want to loan out a camera though...
The Hyena - magician13134, on 05/10/2008, -0/+1Actually, it can, however most remotes aren't powerful enough to work. The Extra High Powered TV-B-Gone designed in the forums at www.ladyada.net has enough power and allows codes to be added, so that will work, in fact, I'm finishing mine up right now, I just needed to verify that it was indeed 18Hz.
- kingm1k3, on 03/02/2009, -0/+1R1 is a potentiometer so yes it is adjustable. I'm not sure what kind he has pictured there but you usually just turn or slide something.
- superchuckles, on 10/12/2007, -0/+1for those wondering about the low power from the schematic on i-hacked...... eliminate the 2n2222 (not needed) & you will find your power output will increase along with the LED brightness. if you want to get the timing perfect, you can use a potentiometer from the output & plug into mic input on sound card & use the sound card as an oscilloscope. if you don't have the timing software, no problem.... record a 60hz hum (easy to find..... just grab unshielded mic wire & instant hum) and compare peaks on 60hz to recorded output of mirt... should be 6 peaks for every 1 peak on the mirt.
- velox, on 10/12/2007, -0/+1I'd really hate to see anyone actually using this, but it's always fun to learn HOW to. That's an interesting article. I especially liked the physical method listed at the bottom of the page.
- audeo, on 10/12/2007, -0/+0So, the I-hacked circuit has been scrapped. Instead, a Xenon strobe with an IR pass filter is going to be constructed and housed in a custom plastic case. Parts are on order. The IR pass filters are pricey though... The last step is to find/build focus housing.
- erckgillis, on 10/12/2007, -0/+0My partner commented on these as illegal, but suggest a IR Mag-light flashlight with the necessary frequency is easier to conceal/explain and has both high power LED's and Xexon bulbs with IR filters avail off the shelf.
We just need a drop-in flashing module! 14.1Hz please...
See
http://www.xenopuselectronix.com/xeled/index.html
http://lumitron.com/Mini-mag%20AA-IR-hood.htm - erckgillis, on 10/12/2007, -0/+0Ok, have been lurking, now my 2 cents.
You need a powerful multi-watt IR "illuminator" or "Military IR strobe". Even a medium power IR laser would work with optics to get a decent IR beam wide enough to target the Traffic detector.
http://www.roithner-laser.com/Kit.htm
Perhaps mounted in the sun visor this would allow 'aiming' directy onto the sensor.
Roithner Laser Supply
1-2 watt LED's
ELJ-880-211, 880 nm, 230 mW / 2.0 W/sr at 1 A, 2.0 V, tr/tf: 10/20 ns, 15°, datasheet
ELJ-940-211, 940 nm, 210 mW / 1.9 W/sr at 1 A, 1.7 V, tr/tf: 600 ns, 15°, datasheet
1-2 watt IR Power emitters
http://www.roithner-laser.com/LED_HP_multi_chip.html
Use 880nM or up for invisable IR strobe
http://tech-led.com/High_Power_Illuminators.shtml
Military & Search & Rescue Strobes are usually Xexon with a IR pass filter. These are usually omnidirectional and would require modification of the strobe rate and some focus housing.
http://www.afmo.com/ACR_MS_2000_M_Infrared_Strobe_p/218-00051.htm
http://www.bhigear.com/index.asp?PageAction=VIEWPROD&ProdID=62
A good hack would be to use old disposable camera flashes with IR filter material and have several in sequence fire & recharge in the req. 14hz range...hum... - tolrtd, on 10/12/2007, -0/+0Assembled my device today off of I-hacked public schematic. The timing circuit works perfectly, and I tried both 10hz and 14hz frequencies (using an oscilloscope to verify). As stated earlier, the POT value for 14hz is ~40k. I've also shorted the 2n2222 to increase the intensity of the IR's. It was tested on a long strip with many lights (all with sensors), and 10hz seemed to do what it is meant to (low priority, keeping lights green longer). Haven't gotten 14hz to work yet where the flood light comes on and you control the intersection, but tomorrow is another day. I am fairly confident in 10hz working, so I believe that the 36 IR array is bright enough to be detected.
Remember, most cameras are equipped with IR filtering lenses - so the IR's do not appear to be very bright. - audeo, on 10/12/2007, -0/+0Would shorting the 2N2222 achieve anything? The combination of the two transistors is a darling pair where the total current gain is given by: Beta = Beta1 x Beta2. When building the I-hacked circuit, the current pre-darlington pair registered @ .03 mA, and after the two transitors read at 51 mA. This is a current gain of 1700, which is pretty decent. The problem is with the LEDs. They are not intense enough. The IR Array yielded .13 mW/cm^2, which is pretty poor IMO (we built a photodiode circuit to test it). The circuit was built with a breadboard using various potentiometer and RC values. We tested the entire spectrum of frequencies from around 9.5 Hz --> 14.5 Hz, and at exactly 10, 14, 14.1 Hz with no effect. We stood underneath the light, in front of it, and in the car from various distances. I recently saw a fire truck with it's mirt being just a strobe on the front of the cab. NO IR FILTER/GLASS, just bright strobe light. I think the key is not IR pulses, it's intense pulses. Please, let me know if you can change a light with the I-hacked schematic, cause I am very skeptical...
- audeo, on 10/12/2007, -0/+0I would say, overall, there are some issues. For starters, the schematic was drawn incorrectly for the 555 section. When building Ihack's timer section, you get square waves with a lot of taper on the edges of the peaks and valleys. This is due to incorrect capacitor placement (the .1 or .01uF), and pin usage on the 555. Not to say it won't work, it's just not ideal. Secondly, his formula for the values of R1 and R2 is very confusing, but is close to being correct though. The entire correct equation involves, f (Hz), C (Farads), and R1 and R2 (Ohms), which allows you vary change all of the component values to achieve any frequency. Lastly, I am doubtful that it is going to change the lights. We found it to be 100% ineffective so far (at 10, 10.1, 14, 14.3 Hz, and full ranges of pot settings on the fly), but have not used the cigarette adapter which is high current. Will carry out final test with final power supply...
All construction was done with a breadboard, digital phosphorous oscilloscope, and a DC power supply. - raspman, on 10/10/2007, -0/+0Any progress on this? I built my circuit and have it set exactly to 14Hz. I even installed a voltage regulator (LM317) to keep the voltage constant... but it still doesn't work.
- RobertGift, on 10/12/2007, -0/+0I just joined. Please forgive if this is already posted.
Many municipalities are unfortunately paying 3M a fortune to encrypt their Opticom systems.
So, even if you mimic the precise preemption frequency, it may not work.
I would never operate one of these if it affected traffic. I'd do it when no one was approaching.
Preemption can ruin traffic flow and cause more use of expensive gasoline and more air pollution.
Also, a new green signal unexpectedly cycling to yellow, then red, may cause a rear-end collision
or give a green signal to vehicles crossing a crosswalk in which a pedestrian is still crossing.
On our emergency medical vehicle, could our fast flashing red LEDs have accidentally triggered Opticom!
They are "ON" steadily for one second, then during the one second "OFF" phase, they blink rapidly.
Could I have accidentally matched the high priority frequency?
We have one intersection where this could really be of help. (US 285 @ S University Blvd in south Denver.)
But, would these LEDs reach far enough to preempt that signal?
We often come up behind traffic backed-up a hundred or more yards behind the red signal.
Thank you, - tolrtd, on 10/12/2007, -0/+0You're correct about that, audeo. I guess through my camera phone the 2n2222 didn't do much to the intensity but there are a few extra mA's. I also noticed something about this unit inside of a car, and corrected the problem. A car's alternator has varied output depending on the RPM, therefore the voltage inside of the car will jump around. As this occurs, the voltage through the circuit (mostly in the timing part) jumps around and causes frequency spikes and such. I had my 'bench tuned 14.035hz' unit inside of a car reading from 8hz to 20 hz. So, I popped an 8v Voltage Regulator (UA7808) onto the board, and the frequency is incredibly stable inside of the car now. I'm using a pocket multimeter with frequency, available at radio shack, to test this, and an oscilloscope to tune it on the bench.
The 8v only goes to the (+) on the 555 timer, and whatever the car outputs goes to the IR's (~12v). Try putting in some sort of voltage stabilizer (apparently the ceramic cap wasn't good enough).
Also, I had the unit running inside my car and had a camera outside at night. While running inside of the car, it was not even visible. The windshield definitely reflects or blocks a LOT of the IR light, but also the headlights and ambient (streetlights) totally overpower this little unit. When the unit was held outside the car (out the window), it was very dim.
My conclusions are as follows:
1) voltage must be regulated if using car power, or frequency jumps around like crazy (or atleast enough to ruin your fine tuning).
2) unit must be much brighter than these IR LED's.
I would rather not build a working device using a visible flash bulb, but at this point I am tempted to do so just to see if this theory works. Perhaps I'll buy a $10 party strobe light and steal the bulb/capacitors. If any of my thoughts here helped, please help me out by sharing yours! - mahans, on 10/12/2007, -0/+0For R1 15-20k is around 14hz depending on the tolerance of your caps and resistors.. So no need for a 500k trimpot, only 150k. Unless you want ot be able to get a 5Hz blink rate.
- OIF2_IFTE, on 10/12/2007, -0/+0still if you want the actual list best if you just become a member of i-hacked and get the actual parts list and detailed scematics for building the PCB.
- PacoBell, on 10/12/2007, -0/+0Congrats. Throroughly informative! I'm still wondering if this couldn't be done with some universal TV remote, tho.
- mahans, on 10/12/2007, -0/+0any one get this to work?, i did some research and the low priority frequency is 9.639Hz in some areas, not sure if it applies every were, 14.035Hz is the high priority frequency. The real devices use a strobe behind a visible light filter and use a frequency crystal to maintain frequency not a 555ic circuit.
- cow_juice, on 10/12/2007, -0/+0by the way, does anyone know what the value of R1 would be to get a 14 Hz flash rate?
- RobertGift, on 10/12/2007, -0/+0P.S. My camcorder "sees" the pulses of our IR TV remote.
Can that be used to verify if the IR LED array is working?
If so, I assume Law Enforcement could record an illegal MIRT in use.
Some selfish idiot was caught using a MIRT in North Denver last year.
He caused a lot of traffic flow disruption in morning and evening rush hours. - BIGGY350z, on 10/12/2007, -0/+0Ok, but R1 isn't actually adjustable is it? How would you adjust the rate of it, or what would have to be added/removed to do that?
- TheHyena, on 10/12/2007, -0/+0have you tried it on any lights?
The Hyena - wildrat, on 10/12/2007, -0/+0I got my frequency meter from BG Micro today and have the gadget adjusted to 10.1 hz. This meter is pretty good for 45 bucks. it does caps,hz,transistors, amp upto 10 etc.etc. Oh well this post does not get much traffic.
WR - gentleben, on 10/12/2007, -0/+0ok, so i'm trying to do this but i haven't had any electronics in 7 years...needless to say i forgot about everything. any help? sbd2a@mtsu.edu
- quartapound, on 10/12/2007, -0/+0i have this circuit, working, however it does not change the traffic lights. i believe the output is just too dim. the emergency vehicles use Xenon bulbs... which are way WAYYY brighter than the leds, no matter how many of them you've got. if you can find a pre-emptive reciever sensitive enough, or if your REALLY lucky in aiming it you may be successful. still a very interesting project though
- v3r71g0, on 10/12/2007, -0/+0Well, I finished this project up. I removed the smaller transistor as mentioned and that seemed to make the LEDs much brighter. If anyone needs help or my detailed Photoshop schematics, just drop me a line at: digitalsamurai@gmail.com
- TheHyena, on 10/12/2007, -0/+0Just for everyone's benefit
>
>Hello i built it from the designs on the public site and I am having
>serious difficuties. I read that are different plans. if you have
>them can you send them to me? I would be gratefull for your help.
>
No, there aren't any different correct plans, the ones they give you if you pay are total *****, so take the schematic on the page and draw it out with a pen and paper in a way that makes sence to you. Then either make your project again or carefully check EVERYTHING twice at least, and not late at night...
The Hyena - TheHyena, on 10/12/2007, -0/+0the_hyena009 at hotmail.com... and no, I've tried it out once, but I knew that the frequency was incorrect... I need to find someone with a camera so that I can test it some more...
The Hyena - vidaesunlibro, on 10/12/2007, -0/+0could you use a picaxe chip to make this? then you wouldnt have to worry about correct resistor values etc, just program in 10Hz and 14Hz and have 2 buttons depending if you want high or low priority.
- TheHyena, on 10/12/2007, -0/+0hey, does anyone know of any way to check the actual frequency besides using a video camera? I am not finding one readily available...
The Hyena - TheHyena, on 10/12/2007, -0/+0are you sure? it seemed like they would let me just order one... if it still doesn't work for you I'm sure there is another online place that has one just like that...
http://www.mouser.com/index.cfm?&handler=data.listcategory&D=*14050Q9104Z*&terms=140-50Q9-104Z&Ntt=*14050Q9104Z*&Dk=1&Ns=SField&N=0&crc=true - krysiu88, on 10/12/2007, -0/+0some one was trying this?
how to change traffic lights
1. A strobe light that pulses 10 or 14 times per second,
2. A way to power it in your car http://www.radioshack.com/search.asp?find=dc+inverter&hp=search&SRC=1&image1.x=32&image1.y=39
3. An infrared pass filter http://www.maxmax.com/aXNite82mmInfrared.asp also check ebay.
Put the IR pass filter over the strobe light plug into the dc inverter and plug the dc inverter into your car then point the stobe at a traffic light that has a preemption sensor and wah lah the light should most definitely change in 2-3 secconds when using 14hz high priority and a little longer with 10hz low priority strobe.
http://www.totse.com/en/bad_ideas/irresponsible_activities/changingtraffi191404.html
maybe someone can tell me with IR filter use, 760nm, 850nm or 950nm??
http://cgi.ebay.com/25mm-IR-Infrared-FILTER-X-Ray-Sony-DCR-DVD-101-201-301_W0QQitemZ7628455277QQihZ017QQcategoryZ48525QQrdZ1QQcmdZViewItem - TheHyena, on 10/12/2007, -0/+0you have the one that you get if you're a member? I would like to check it out if its different, see if there is anything effecting the amperage or anything...
The Hyena - wildrat, on 10/12/2007, -0/+0Well I have tried posting twice now with no success.
I built the circuit above using what was on I Hack. My gadget worked fine. It was not very bright till I removed the 2n2222, now it's brighter. I am going to plug it into my Motorcycle Cigarette lighter, it's output is just above 14 volts, so it'll be a little brighter still. I ordered a cheap multimeter yesterday that has a frequency function on it. I will use it to play with the frequency. After I get the freq's set I will put the PCB's in a plastic case I got from Mouser. The case is used for making a remote. It has a battery compartment so I might put some 12V batteries in it for alternate power. Anyway when I get it in the case I will go test it somewhere. Catch ya later!
WR - Hurricane, on 10/10/2007, -1/+1LMAO, ressurect this old article......
- superchuckles, on 10/11/2007, -0/+0oh yeah...... another "obstacle"..... the ir pass.... you can get 77mm filters (big enough to use on front of a modified flashlight body) on ebay for about $36 anywhere from 780nm (partially visible with a photo strobe) down to 900nm or lower (in optical glass no less). so now you have what looks like a mag light, but emits no visible light to the human eye & makes a faint & fast clicking noise when turned on. enjoy.
- wackogracko, on 10/12/2007, -0/+0anyone know how to tell the difference between encrypted preemtive recievers and non?
- andrewjm, on 10/12/2007, -0/+0can someone send me diagrams for the one they have working? I can't seem to get it to work. temp4@andrewjm.com -- thanks
- uvagrizzly, on 10/12/2007, -0/+0i have been trying to build one of these for my volunteer rescue squad (donations are tough to get, trying to strech them as far as possible). the timing circuit works perfect, but im not getting anywhere near the level of output claimed by the I-hacked directions. the total load of the entire project (timing and led circuits) is only as much as one of the leds is rated to draw (100 mA). according to my calculations the whole project should pull about 3 amps with all of the leds running at max power. just for verification i hooked up an IR receiver to an O-scope.... a standard 3 D-cell flashlight emits about 5 times as much IR light as this system as it is now. has anyone else had similar difficulty, or better yet found a solution?
- astral125, on 10/12/2007, -0/+0did you get yours working right? mine seemed underpowered as well and i could not capture any traffic lights in my area at night. when i pressed the board down a little i think i would short something, because on camera, the LEDs would become super bright, but also go to solid instead of flashing. i am going to redo ever thing, in hopes of fixing this so it is brighter.
- TheHyena, on 10/12/2007, -0/+0The schematics on the site are good, if you follow those carefully and triple-check your work and pin-outs you should be fine. if you need more instruction analyze and get a more focused question.
The Hyena - gpgames, on 10/12/2007, -0/+0i know that using the 555 timer makes this project really basic so that pretty much anyone with any knowledge of electronics can build it. i would go a very different way. i would either use a crystal or perhaps a small PIC chip (like a small 16 series) with a possible 2 freqency switch. if i was to ever use one of these i would definately use it at the 9.xxxxx frequency so that if any real emergency vehicle with the 14.xxx frequency was to be going on the perpendicular road, it would have priority. PICs are really easy to program, especially with picbasic, they have an intetrnal oscialltor that will keep the frequency stable, and would make this project way better i think.
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