REAL cell phone remote relay \ remote firework starter

I am sure you have already seen the cellphone detonator by shootingeggs (who rule by the way), but unfortunately it is unsteady, requires semi or fully permanent installation, you can not swap the sim card and it is just plain too simple to my taste. It is why I made my own remote electronic relay. (you won't find this anywhere, I made it:) )

HOW THIS THING WORKS:
The module has 3 pairs of wires.
1- imput
2- output
3- phone plug

1-(2 long wires at the bottom) imput is you battery pack. You need a minimum of 5 volts.
2-(2 short wires next to the LED) the output is where you plug the fuse. It always leaks 1.45volts until the whole thing is activated - it is activated by part 3
3-(black plug imput) phone plug, this is where the cellphone is pluged (you will see how this is done in later steps). When the phone rings, it will open up a passage for ALL of the voltage to go from 1(imput) to 2(output) WITHOUT touching 3(cell phone); this means you will NOT fry the phone as no electricity goes in there.

Summary: when you call your phone connected to this, it will activate what is pluged on the output (be it a model rocket fuse, or a more powerful latching 2$ relay that controls a 120v device).

Step 1 Here is the basic schematic and the parts you will need.

parts drawn on board (you can see an un-ubstorced board on the intro picture):

-555 IC timer (on which pin 1 is identified, I use a TA7555P chip)
-resistors : 33kohm, 467ohm, 1kohm
-Capacitors: 0.1uf and 0.01uf
-a plug that will fit the wire you will put in your phone, a cellphone and the cable that fits in the plug you used.

Optional: (it is a testing mechanism to see if your circuit works when the phone is rigning)
- 1 pushbutton or switch
- 1 LED; the positive (longer leg) is the top 5 on the schematic

The 555 timer IC chip used here WILL heat when the cellphone rings so do not touch it but it should not be damaged. If it is, swap it (its why I put mine in a IC socket, for 80 cents, id rather throw it out and swap it in case of problems rather then starting from scratch again.) This chip was not made for this, its why you will never find this circuit anywhere else (for now :p)

Comments

[greenhey]

Dont use the schematic just go off the picture of the board layout.On the schematic the fuse output on pin 2 should be connected to pin3 and and the 470 resistor goes from pin3 to pin 2.I removed the vibrator motor and connected to wires in its place which gave me 1.2v then used this to switch a transistor to get 9v output using a old nokia.

[julienrl]

Oh my, thank you very much. With some comments I had I had a feeling there was a mistake, but every time I rechecked it, I could never figure out if/where something was wrong in the schematic. You are absolutely right, the fuse on pin 2 should be going to pin 3.

[RetroPlayer]

It is possible to do this without modifying your cell phone. I have a cell phone cradle on my desk that flashes when receiving an incoming call. Bought on Ebay a couple years ago. Also, there have been circuits all over the internet to do this:
http://www.redcircuits.com/Page47.htm

These work because your cell phone emits a signal just before it rings, and these simple circuits detect that signal and trigger. It needs to be placed very close to your phone, but does not require you to modify your phone at all.

My flashing cradle, unfortunately doesn't work with Verizon, which is my carrier, but it works with my brother's sprint/pcs phone.

[cool not lame]

were can u get all these wires and stuff?

[peanutthegreat]

I think if you have to ask where to get wires, you shouldn't be building this.

[julienrl]

thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you thank you !!!!!!!!!!!!!!!!!!!!!!!!!!!! As for cool not lame, start with the basics, the best way to start is by dismantling stuff people are throwing out. Older things (80's and such) are easier and better for scavenging and learning.

[freerunnin1]

you could always remove the motor that it uses when its in vibrate mode and connect those wires to a camera flash circuit and then from there put the output to a wire and connect that wire to the fuse... if you get what i mean.. :P

[julienrl]

um... I am not sure if the motor is fed with enough power to supply a flash circuit, but that would also make it useless for anything that needs a controlled output :p

[Smartzkid]

I've oft thought of building something much like this; instead of using the buzzer voltage, I want to 'listen' for certain frequency sine waves from the speaker. With a tone generator on the other end, one could use this system to control complex configurations of fireworks with far less wire than your average programmable system.

It actually wouldn't be too hard to build - using a microcontroller to A2D the 'output' cellphone's speaker and calculating the frequency, implementing a call auto-accepter (easy with a microcontroller), and building a bank of output transistors to sit between microcontroller and detonators. This would allow for the control of an arbitrary number of fireworks; the only limiting factor is call quality, which impacts how accurately frequencies can be matched.


Does anyone know of a super cheap prepaid phone service? I can't just go out and buy a junky SIM phone; Verizon doesn't use SIM cards :(

[tristantech]

Actually, you can buy chips that they use in telephones that actually decode the DTFM tones from the keypad and output that number as binary or BCD.

[Smartzkid]

This would also solve the 'wrong number' call problem; if the microcontroller did not detect the frequency 'protocol' it was expecting, it could hang up after a short period of time.

[julienrl]

that does sound pretty cool; kind of like the same idea as a modem except the sounds would trigger various switches... but at this point I don't think that this circuit would be very efficient.

[gin_road]

Could I also wire this to a old cordless phone. Hooking it up to speaker of phone and using Page button on phone base/rechargeer unit to ring phone?

[julienrl]

as long as the circuit is open until the phone is paged at the point where your leads are going; best way to know is with a multimeter (using continuity mode or resistance if that is not available and if resistance is not available, low DC voltage measurement, but that is not ideal due to the low voltage you are measuring)

[guitarman63mm]

I see that only a select few see this for what it is...a piece of technology almost NEVER utilized for fireworks, and almost exclusively for ieds.  Now, I'm not going to go and say that we should try to control a simple schematic that any competent person in electronics could make, but if you can seriously convince me this will be used for fireworks, I challenge you.

[subbatonikk]

I built a circuit on a similar vein to this a while back and have just built another one with more advanced functions. I use it to remotely control a test rig so that I can troubleshoot phone lines without having to keep driving distances to put a short, a tone or a DSL signal on the line. I have very rudimentary electronic skills and knowledge gained just less than 30 yrs ago. I was able to design the circuit from memory and utilizing a couple of kits. If you google "sound activated switch relay' such kits are abundant. Terrorists are sophisticated intelligent people (albeit inhumane & viscious criminals). They are usually connected to networks of people some of whom probably have degrees in electronics/ electrical engineering.  BE REALISTIC and THINK before you insinuate!!  Julienrl is just being open and helpful about a modification to a well worn idea.  Why spoil his fun!!

[guitarman63mm]

     As I said in my second comment, it's not about using a remote trigger for testing applications, it's about using it for 'fireworks'.  Also, for what it's worth, a blanket statement on 'terrorists' is unwise, as they will inherently vary in intellect.
    

[julienrl]

I know what it can be used for and its the reason I debated many times over pulling this, its also the reason why I have repeatedly told people that I would not make it any simpler. In the end, many things can be used wrongly.

ps. this was made because I like making stuff and was used once (at a very safe distance) for my scout troupe.

[guitarman63mm]

      That's a very true statement, and as I said, I'm not asking you to pull it, nor am I trying to control knowledge, as that is the opposite of this site's purpose.  
     Although you've stated an example of what you used it for, that's akin to saying you used a rifle's stock to dig a hole;  the main purpose of a rifle is to shoot, the main purpose of this device will be to detonate an explosive charge, which is precisely what you built it to do; the only issue is that the chances of someone utilizing this on the 4th of July for their fountains, as opposed to IEDs, are slim to none.

P.S. The title has a misspelled word in it...'fierwork'.  That in itself might lead one to believe this is an 'ible of suspect origins.

[julienrl]

ya but whats kept me from pulling it is the idea that if someone wants to use an IED, they are probably very motivated and would most likely not need this page to follow through, especially given the technically simply existing instructables out there (note the shootingeggs one I refer to)

ps. thanks, I had not noticed that!

[Rainh2o]

I second this challenge  :(

[julienrl]

ummm the fact that this is a DIY project for someone who wants a fun project? If you really want a detonator that is simple and takes about 5 min to make just look at the few year old shooting eggs video that I refer to.

It 1- has no voltage leakage,
2- can be used with any voltage,
3- takes NO expertise or skills and finally
4- it only needs a battery  2 wires and the phone, nothing else (well maybe a bit of tape).

I am tired of being apologetic about this project, it is what it is... if you really want to blow stuff up, this is not the simplest way, this is useful for someone who wants a reusable DIY project. If you want a single use, there are waaaaaaaaaaaaay easier ways and if you want a easy reusable non-diy relay, you can buy relays online for about 50 to 200$ (depending on what precision you want), ready made that have much better voltage control)

[upritam]

Your idea is great. I WANT TO LIGHT A FLUORESCENT TUBE IN MY BARE HANDS WITHOUT ANY VISIBLE MEAN. i AM SEEKING YOUR EXPERT ADVISE ' THANKS ALL ELECTRONIC GURUS.

[Naesen]

You can make a wireless power transmission system using an ac electromagnet.

[Rainh2o]

If I was going to make a detonat...ummm.."fireworks starter" and didn't want to tear up the cell phone, i would just use a photo transistor connected to a simple switch circuit...then set the cell phone to light up when called..less intrusive to the cell phone.

[beazll09]

what is the best and most easiest phone to modify to do this?

[julienrl]

I have only modified one, but I assume they will all be pretty much the same. ps. please be responsible with this.

[BigNateMI]

A bit late for that, I think.

[ReCreate]

just don't go with an iphone

[beazll09]

i will. what model phone did u use? they are not some phones use cables and some just use flat surfaces pushed together but i have found that motorola phones are the best for what is needed for this project.

[julienrl]

I use a motorala V220, I got it from the store, he was about to send it in for repaired because the 5 wasn't working so I bought it for 40$, unlocked cellphone for 40$ in canada is just unheard of :p Sorry for the delay in the answer

[Snarky]

I get "wrong number" calls on my cell sometimes as often as three times a week. I realize you would want to use a "fresh" phone for this, but what would you do to prevent a "wrong number" call detonation?

[higgzy77]

Sorry for my lack of knowledge but how does the 555 timer work?

[lordofthedonuts]

The 555 is a widely used chip, it'd be complicated to explain how it works without taking like 5 pages because it can be configured in so many ways.
It really depends on how you wan't to use it.
For most people the 555 is their first IC cuz it's so versatile, easy to use and just plain awesome. You can find many comprehensive schematics online.

[SinAmos]

Terrorism has made it's way to instructables.  Good job.

[sii2009]

 is there anyway you can stop the 1,45 voltage leakage, maybe by a resistor or instead adding a relay switch to the output onto another circuit :)

[JerryMopar]

Nice, now ANYONE can make an IED!!

[roycetaft]

Wouldn't it just be easier to use a small relay instead of an entire circut? idk..
Oh and I was confused about something, when you say "imput", do you mean "input" ?  Overall, great concept.  With a little black powder you could remotely scare the crap out of someone. lol

[judgedead]

 hey thanks i was wondering how to remotely detonate a bomb and now i know look out

[subbatonikk]

2 suggestions for improvements: 1) To isolate the output of your circuit from the firework starter you could add a 'normally off' relay to your output. When cellphone rings the relay is energised and completes a circuit to the battery. This would eliminate the problem of the always present voltage on the output. Would probably need a small transistor added also to provide the energizing current. 2) Many cellphones have jacks for a headset which deactivate the speaker. Wiring a lead with the right size plug to your circuit would allow you to attach/remove cellphone without having to modify it. I built a cellphone activated circuit which switched (sequentially) a series of 8 relays to control various test equipment remotely but I relied on 'sound' activation. The problem with this is ambient noise can trigger it. I will be looking at incorporating your idea. Thanks