[Mr. Hasselhoff] is using a disposable cell phone to trigger his fireworks. He has wired into the speaker leads for the speaker phone. When the phone rings, the current sets off a thyristor allowing for a battery pack to be discharged into a rocket fuse. These fuses heat up and ignite, so you can use them to light fireworks fuses pretty easily. This is pretty simple and cheap, considering the price of the cell phone was only $10. His next idea was to have it recognize dial tones and set individual fuses off, but that would require a microcontroller and a much more complex hack. At that point, you might as well just build a fully fledged wireless fireworks launching system and possibly add rocket launching abilities too.
[thanks Adam]
OOOOOOOK. So look, as this may look really really bad, there is a lot of truth in the matter. This particular project uses a VERY poor thyristor design.
When the switch is set to ‘on’, the battery immediately begins feeding current (a LOT of current) to the thyristor, whether or not the cell phone is called.
So, to get this to work, the cell phone must be called within about 2-5 minutes of switching it on or the battery is dead and it will not burn the fuse.
Not the best solution for someone who wants to use it for naughty things…
OOOOOOOK. So look, as this may look really really bad, there is a lot of truth in the matter. This particular project uses a VERY poor thyristor design.
When the switch is set to ‘on’, the battery immediately begins feeding current (a LOT of current) to the thyristor, whether or not the cell phone is called.
So, to get this to work, the cell phone must be called within about 2-5 minutes of switching it on or the battery is dead and it will not burn the fuse.
Not the best solution for someone who wants to use it for naughty things….
sry for duplicate post.
hey everyone should freak out about this….oh wait.
so, if this was posted as “how to make a remote controlled switch with a mobile phone” it would be ok?
this information exists and posting it here is no more dangerous than google indexing a site that has information. if you type “how to make _______ into google one of the first entries on autofill is “bomb.” People are searching for this already and the information is readily available. Deal with it, free speech ftw.
adam- spare us the ‘information wants to be free’ crap. What’s your full name, address, ssn and dob?
What about using a relay and the power for the vibe motor?
@jimmys: actually the SSN would suffice for finding someone.
he forgot to include an extra $1 in the build cost for a “la bamba” ringtone
Sweet, now I can build my own roadside fireworks displays! If this had not been posted here I would never have known how to do it because my parents only let my have access to this one site!
In regards to IEDs:
yes terrorists use cell phones to set of IEDs, this is common and trival to do, and nobody is getting any new ideas from this guy’s post.
Blocking radio signals also sets off IEDs. Some terrorists in Iraq figured out that coalition forces have blocked radio detonators and have set bombs to go off when a signal is lost rather than by sending a signal.
They also continue to use radio detonators.
tech really isn’t the way to solve this problem, other than armor anyway.
yah know, at first I was considering calling for a post removal. this is, as it exists, a bad idea, for a number of reasons, as mentioned by everyone here.
I see the potential for this project to be fine for a number of *other* uses, but fireworks is not one of them. anyone with pyro experience will tell you. several people have defended the project for other uses, and i can agree with them at least on those points.
a marked improvement, that would make it much more reliable and safe, would be to route the speaker jack to an answer and dtmf decoder circuit. this way, the phone would pick up, and listen for a sequence code (or a number of codes, if you wanted multiple triggers). such designs have been around since the 80s (if not before).
the answer/dtmf decoder setup would add a lot to the safety factor, as well as make it far more useful.
Id like to add: some things should not be done cheap.
remote ignition in this way adds no real margin of safety to preparing the site. while attaching the device, you run the risk of someone else remotely triggering the device. that is, anyone with access to the number, or any ‘accidental’ call.
The only way to add some remote form of disarm/arm is to add some intelligence somehow (such as the dtmf devices as mentioned above).
A far more interesting hack would have been to modify the firmware of the phone in such a way as to automatically answer a call from a specific number, then wait for the proper code to be entered by the caller, before finally vibrating the motor. with vibration set to off for all other functions, you have thus eliminated the dtmf circuit, while still safely adding n verification system before triggering.
mre-
I’m not sure that dtmf works properly over compressed digital audio.
I think what would have been cooler is to see that some how used to trigger a PC to auto-Fdisk.
But thing again it would suck to have all your pr0n lost because of a wrong number :\
GET OVER IT TERRORISTS STILL USE WIRES TO TRIP THE DAMN BOMBS IF THEY HAVE TO< THIS ISN’T THAT BAD!!!!
Look, I don’t know about the legality of this hack, but let me address a few points:
If you want to ensure that the phone does not trigger your explosives while you are setting up the device, use some longer wire to locate the phone a reasonable distance from the explosive, connecting the igniter end first, phone end second.
If you are concerned that someone else will dial a wrong number, set the phone to only ring when your specific number is recognized. This can be done a number of ways, depending on the model.
On cellphones it is *extremely* unlikely that any RF noise will cause the phone to ring. Even if that is the intent of the producer of said “noise.” The most likely result of broadcasts over a wide band is that your intended signal will be jammed and the phone will not ring when you call it.
All that said, I would not advise wireless detonation of any kind. It’s easy to forget any one simple precaution and kill yourself or someone else. You should never need to be far enough away that you can’t see your fireworks’ launch point anyway.
Hello, What kind of thyristor, size etc should you use? I have a 6V battery to powerr the rocket fuse.
this is sort of like what terrorists may use to trigger a bomb.
the movie collateral damage the terrorist uses a cell phone to trigger a bomb.