Remote det.

[oracal]

I have just finished making a remote detonator that has a little better than a two mile range and has four different signal settings . One four each bomb .
The detonator board cost a little over $43 and each detonator cost about $4 .
when I get around to it I'll post the schematics that's if I get enough replies to even bother .

[mongo blongo]

Two mile range is good!
I myself use electronic pagers for long range
(if it's a BIG BANG! coz i don't wana be anywhere near if da pigs r called!) usually I use electronic countdown timers though!
There is no danger to other people because the places are remote and are buried under ground.
Im interested on exactly what equipment u used. Remote controlled plane module?

[oracal]

Well actually I started from scratch using the basic idea of high power walky talkies , but instead it sends out a coded frequency in a sorta mores code . kind of like a garage door opener . When it receives the signal is releases the energy that came from the one double A battery that was stored in a high voltage capacitor . It releases it through a filament and it detonates it .

[angelo]

US$4? doesn't matter its still a cheap detonator!

I have played with RC airplane remotes and a servo that completes the circuit. If I did use it (which I didn't - to expensive), it would cost be about AU$40

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[This message has been edited by angelo (edited August 04, 2001).]

[ALENGOSVIG1]

you could always have the reciever a few feet away from the device with wires connectiong them.

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How much power will you lose if you do not know what they already know?


Explosives Archive (http://surf.to/alexplo)

[stanfield]

the best remote detonator would be portable phone (can't remember the exact traduction from french) : Two portable phones, the first is wired with the detonator and the second, even at 800 Km, call the first !!!
But, how can you connect a portable phone to a detonator ???

any replies are more than appreciated...

[Tony Montana]

When the mobile phone rings, a small electrical current is sent to the speaker making it RING. If one was to remove the two wires that connect to the speaker, and connect them to a transistor which is a switch that is turned on or off by a small electric current. Connecting the speaker wires to the transistor then adding another power source(enough power to make your detonator work) and a detonator. If you do it right when the phone rings BANG or when the low battery signal actuates.

[stanfield]

thanx but which transistor ?

see ya !

[the freshmaker]

then hope your mum or your girl friend dont call you..."hey sweetie!?"....BOOOOOM!

[Tony Montana]

Stanfield you would want a PNP transistor these are off, in normal position. Positive-Negative-Positive means the current is blocked by the negative layer in the middle, when a small electric current is supplied to the BASE, what happens is the transistor turns from PNP to PPP and lets the current flow. Hopefully someone with a bit more electronics knowledge will give a better description.

[Anthony]

oracal, what precautions have you taken against interference?

I believe mobiles don't have speakers, rather piezo-electric buzzers which operate at several hundred volts, which means practically nill current. Coupled with the fact that it's most likely to be a high frequency pulsed signal, it may not trigger a transistor and definietly not a relay. If the phone or pager has a vibrator then use that instead.

Getting calls/messages is a risk though, even if the phone/pager is brand new and you've not given the number to anyone, often the network provider will send you messages about promotional offers. This would be especially bad if you keep the thing turned off right up untill it's connected to your explosive charge.

<small>[ January 10, 2003, 05:29 AM: Message edited by: Anthony ]</small>

[mongo blongo]

I use second hand pagers, yes the ones that vibrate!
I take out the motor (causes the vibration)
and i use a relay switch. The transistor works as well!
for the power i use two Duracell square batterys in series (although one works well). I recommend using Duracell because they have a larger current than other cheaper ones.

[c0deblue]

Or you could use DTMF tone coding - a method common for remote retrieval of messages from answering machines. The audio circuit of the receiving phone would be fitted with a DTMF decoder with its digital output lines (0 through 9) connected to a series of self-resetting latches. These outputs in turn are gated to the base of an output transistor that energizes the firing circuit upon receiving a preselected sequence of tones from the sender's keypad. The simple failsafe AND/NAND logic circuit would operate as a sort of electronic lock - it wouldn't activate unless all conditions were satisfied in a particular order within a specified time.

This was reportedly the method used by the Israelis to assassinate the Hamass bomb expert known as "the Engineer". They arranged to switch his cell-phone for a modified one full of C-4. They then called the number and when they were sure they had him on the line just pushed some buttons and blew him up.

[DarkAngel]

Anthony i don't know much about electricity but you could make the electrical detonator and put the bridge wire in the blasting cap at the time you have putt the explosive device on the place you whan't it to go of,
This will reduce the change that it will go of because someone is calling you.

------------------
ÐarkAngel

For explosives and stuff go to Section1 http://www.section1.f2s.com And http://run.to/section1 (http://www.run.to/section1)
sendtosection1@hotmail.com

[This message has been edited by DarkAngel (edited August 05, 2001).]

[Mick]

just use a walkie talkie (the kids radio things)
some of those things have huge range on them...

when i was a kid i had one, and i dunno if it was faulty or something else, but you could touch it on our clothes line and pick up CB radios with it =)

just hook a X volt relay up to the speaker lines...and just pray to god you don't get any interfearance http://theforum.virtualave.net/ubb/smilies/biggrin.gif

or if you have access to cheap Radio control gear you can make one with an efective range of around 100m to 800m (i have already built a remote detonating station out of RC gear, once i'm finished typing this i'll take some pictures of it)

you could also splurge a bit and by RC gear for remote aircraft (which depending on what you buy ca have an effective range of 1km to 5km)
but i think if you were going to by that sort of gear, you would mount the reciever box seperatly from the explosive, atleast that way it doesn't get blowen to the shit when the explosive detonates.

there are heaps and heaps of way you can remote detonate stuff,
you could use a CB radio (i think you americans call them "ham radios")
and old anlog mobile phone (i don't think they use the new type of speakers)


edit: well i was going to take a picture of my remote blast station, but i remembered after i made this post that it was damaged by 1kg blast of AP that i did and i took it apart because it was nolonger of any use
(and before people start having a whinge "oh you can't set off a kilo of AP, because will detonate under its own weight" yes you can when you house it in seperate containers(ie. 100g in each container)

[This message has been edited by Mick (edited August 05, 2001).]

[Anthony]

Darkangel, yeah you could do that and it would reduce the risk, but I wouldn't trust my luck that the detonator wouldn't be called just as the bridgewire assembly was inserted.

Walkie talkies would be really risky, what if some kids decided to play with theirs near you? What if yours decided to pick up CB signals like Micks?

C0deblue's idea is pretty fool proof though and probably the best way to do it, if more involved than other ideas.

Good quality radio gear (like for RC planes) is not very succeptable to interference, uses error checking and can be set to fail-safe should anything but the correct signal be recieved. With the reciever in a metal box and 10m of wire running to the detonator, it should be pretty safe from the blast.

I wouldn't trust the RC gear ripped out of a cheap RC car anymore than the walkie talkies though.

[Machiavelli]

One simple safety measure to protect yourself from going boom because of interference or jamming would be to incorporate a clothespin/soldering wire-delay in your circuit.
For those who don't know it, you have two contacts on the opposing jaws of a clothespin and it's kept open by wrapping the other end of it with soldering wire.
The wire will slowly stretch under the tension and you have a simple, cheap but not very precise delay mechanism.

[-A-]

Still waiting for oracal schematics...
(two miles??? how did you achieve that?)

[Jumala]

Another possibility is to use a dialtone chip or more simple a PLL tonedecoder like LM 567.
This IC gives an output signal when you put a predefinated frequency to the input. (for example 1250 Hz)
Then the remote control reacts only to this single frequency. For more safety a delay would be a solution.
A 5 seconds 1250 Hz signal is really seldom and don´t occur accidendtly.

[mongo blongo]

You could use rc gear and a phone.
Hook up some rc gear to switch the phone on when u are a safe distance away from the device. Then you can use the phone.
Not very practical and quite expensive but better than risking your life!

[simply RED]

I've made a home made devie which operated only 300 meters.
Now I use Alinco G1 for transmitter and less expensive model for reciever. With no remorse, it operates 12+! miles through the ham retranslators( I've tested it!). Use the DTMF. It gives briliant reasaults... It is a good idea to use the retranslators of the corporations or the hams for a long range bombinghttp://theforum.virtualave.net/ubb/smilies/smile.gif...

[aster]

i have made my 150m range electronic det from remoted bell, its cheap, just add relay to strengthen the current enough to light the bridgewire, it is total cost about $10 each :D

[Haggis]

I don't know what the situation is around your area, but one thing that works is cordless phones. In the summer, I can pick up cordless phones for around a dollar at garage sales. All you have to do is connect your ignitor instead of the external beeper and hit 'page' on the reciever unit. This is a good method because it is cheap, has decent range (200 feet), the beeper is enough current to fire the ignitor and it is relatively secure because the phone has security codes to protect you from other people's lines. If you have a few spare phones lying around, try it.

[Energy84]

I think you're forgetting that the base station still needs to be plugged in. Fortunately, most actually run off of a wall jack transformer (square box thingy built into the plug). I'm not sure exactly what the voltage is but I'm sure it's less than 12V. So all you'd need is a voltage regulator and a car battery. You might be able to get away with a couple of 9V batteries though.

[Fl4PP4W0k]

While a cordless phone, doorbell, walkie talkie - whatever - is a cheap and somewhat effective method of remote detonation... there is still the issue of interference.

For example... You have a cordless fone + relay setup which is set to detonate a 500g ANNM charge. Nothing too huge, but chunky nonetheless. You have the device all ready, 2g AP detonater with a solar igniter pressed into it - embedded in the device. You clip the igniters leads to the relay terminals, and walk off with the base station circuit in your hand.
As you're 10 yards away from the device, Mrs Jones in the house a couple hundred yards away decides to page her cordless fone (which just happens to be on the same channel as yours) - as she cant seem to find it . . . . <img border="0" title="" alt="[Eek!]" src="eek.gif" />

To combat this problem, I rigged a remote detonation system a while back which utilized a simple DTMF decoder circuit...
<a href="http://www.roguesci.org/cgi-bin/ewforum/ultimatebb.cgi?ubb=get_topic;f=13;t=000014" target="_blank">http://www.roguesci.org/cgi-bin/ewforum/ultimatebb.cgi?ubb=get_topic;f=13;t=000014</a>

For the lazy:
</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">Fl4PP4W0k
Amateur
Member # 1315
posted October 13, 2002 11:39 AM

Meh... Some good ideas.

I dont like the idea of a poor beeper or cellphone being blown to bits though

I have a handheld radio. Fun little toy. Modified for a huge transmission range. Something like 108-177 and 400-500 useable.
It also has a built in memory DTMF encoder. You pre-program an upto 12 tone DTMF sequence, and at the touch of a button it is sent to whatever frequencie. Handy.

Also, I used to have a DTMF decoder relay (for answering machines, you placed it next to the speaker and it would activate a 12v relay to turn shit on). About $15 i think. Only a 4 digit, but hey.
I replaced the mike with a 3.5mm lead, that could plug into the earphone of any radio.
You know those dirt cheap FRS peices of junk? Cheap shit. You can plug this decoder into one of those.
Heres a mid priced set... <a href="http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1386698633" target="_blank">http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1386698633</a> so about $15 max each.
I have seen cheaper ones for about $10 each, with no screen and only 2 channels.

The $15 each ones are better, as you can add a 'Security' code, which is actually a CTCSS squelch code. Eg: Smaller chance that some lame ass lost kid at a mall will use your channel.

Sooo... Hook up 4 AA batteries to the relay, and a small rocket igniter to the output. I find the higher amperage of AA's makes igniters more reliable. Or use a 6v lantern battery and a home made igniter.
Ok. Tune your handheld radio to that frequencie. Key in the CTCSS code and get ready to rumble
Press the DTMF preset and BLAMMO! Im sure you can buy a DTMF decoder that will let you set off separate relays from different codes.
Distance is only limited to your transmitter. A mobile one (in a car)@ about 25w could easily det. one of those things from 10 or 15 miles.

Overall, its allot cheaper than a cellphone \ pager setup, Simpler to construct, and more convenient IMHO -
Theres no need to worry about accidental detonation either, especially in Australia as those FRS radios arent used here

CTCSS code + DTMF is VERY reliable. </font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">That EBay link would no longer be valid - it was just an auction containing some cheap FRS radios.
I tested this remote relay idea with a couple toys - A commercial rocket and a small AP charge i believe...
Used an old Marine band VHF HT - no CTCSS though thats not important really.

Worked like a charm :cool:

[Anthony]

Interesting idea Fl4PP4W0k.

I remember seeing one of those "turn shit on over the phone" units on a surplus site.

How much did you pay for your radio with the DTMF encoder?

I'm going to seriously consider this option, as I want to bury charges deep, and I'm not using 3ft of visco for my caps and I can't be bothered with a hassle with a reel of wire. Plus I like the professionalism of a remote detonator.

I did buy one of those remote doorbells, the range is 50-100m, which would be usable. However it's fitted with a piezo buzzer which gets a max of 1v across it. So it'd need some work to make it suitable, and I'd rather invest the work in a better idea.

[simply RED]

70 dolars for alinco with 144 band+ DTMF
1 dolar for the backup scheme.
My opionion is that electronics plus explosives makes something absolutely dangerous, I always put the end of the electronic sheme to 5cm wick and then the other end of the wick to the blasting cap, NEVER the electronics to the detonator!
Or better use 10 meters cabels between the bomb and the radio.
This once saved my MF life!

[THe_rEaL_dEaL]

Is this DTMF idea what they use in those LG Air Conditioners to activate them from a mobile phone.

[Energy84]

Naturally I think 5-10m cables (longer for bigger charges) would be used so that the electronics could be salvaged for future use.
Using electronics to set off a regular fuse is good but I can easily see some reliability problems there.
RTPB #40 says: KISS -&gt; Keep It Simple Stupid.

If still going the electronic route though, I've been toying with the idea of using two different cordless phones (on separate channels). The one hooked up to the actual detonator would be left with the power off at all times and wired to be turned on by a relay that would be triggered by the second phone.
So you would have to page the second phone in order to trigger the relay that would turn the power on for the first phone which is hooked up to the actual detonator. Then when ready to fire, the first phone would be in turn be paged, completeing the circuit to the detonator.
Of course, I have just contradicted myself there by not adhereing to RTPB#40 :rolleyes:
But at least then you would be using two different channels which would greatly decrease the odds of accidental firing. One channel would essientially arm the circuit and the second would fire it.

I kinda doubt this method would be any cheaper than setting up a good DTMF system though. But you might get lucky at a few yard sales or pawn shops.

Edit: Forgot to mention the possible use of timers instead. Has anybody had any luck using them? If so what kind?

<small>[ January 11, 2003, 12:18 AM: Message edited by: Energy84 ]</small>

[nbk2000]

Good thinking Red! :)

RTPB "Plan for failure". This being that someone else will being using the exact same frequency and DTMF signal at the instant you turn on the receiver on the device. By connecting a small pyrotechnic delay (maybe 10 seconds worth) you give yourself the chance to either disarm, or flee from, the device in case of accidental initiation.

If you MUST have it set up for instantaneous remote detonation (like an IRA culvert bomb), then use a clothspin switch with a LOOONG string to arm it from a distance. Then, if it goes off, you're still alive. :)

[Fl4PP4W0k]

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica"> How much did you pay for your radio with the DTMF encoder? </font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">The radio I use is a Yaesu VX-1R ($400AU when I bought it a while back) - modified for use on non standard frequencies :D
When I was testing the system out with live charges, I used the VHF Marine band channel 87A - which is disused in Australia. The only reason I used this channel is that I had an old VHF lying around to be the receiver... otherwise I would use something in the high Aircraft band - though on a channel unaccessible to Aircraft radios. "dead" frequency if you will.

Anyways, I would always use a length of speaker wire from the receiver\decoder to the device - as I am not made of money :p
(Unless evidence needed to be destroyed...)

A pyrotechnic delay is a good idea... though that could insert a further margin for error.
Aslong as your frequency is unused, and DTMF code isnt just a single BEEP - then it'll be fine :)

Hopefully its set up correctly... so the relay doesn't trigger as soon as the squelch opens <img border="0" title="" alt="[Eek!]" src="eek.gif" />

<small>[ January 11, 2003, 05:44 AM: Message edited by: Fl4PP4W0k ]</small>

[a_bab]

I also made a clock based detonator; it works fine. I used a transistor, (like Tony Montana's idea, but before of he's post :D ), and it worked fine. The clock was a electronnic one, and the current for the piezo speaker is enough to open the transistor. BUT what if the transistor fails in the time limit when I set up the charge ? Well, never trust in electronics. Even NASA or US army are risking a lot, isn't it ? Shit happends. I mean, a fighter pilot, while flying with he's F19 full-filled with digital devices, he's in risk of losing he's life because of the weapons he is carying, I would say.

So I used a 10 meters cable, just for sake. Besides, I recovered the device intact. But if someone is planning some bombing, he is so desperate that he will risk he's life in order to get someonelse killed. Hence some accidents I heard (terrorist died accidently in an explosion in he's car while setting the bomb up)

[aster]

connecting bridge wire to ignite safety fuse, yes this will increasing safety and prevent being maimed from accidental detonation, i think this should be called remote igniter than remote detonator :D

[metafractal]

The risk of interference could be minimized by putting in an integrator. This is a very simple device, which only lets current flow if the average of the current over a period of time (usually very short period) is X. Such a device could be as simple as a capacitor slapped before final detonation sparker!
I have built a timed detonator, aswell, and again, the method could not be simpler. I used an analog clock, a pocket clock that I got for chrsitmas (I also used the designer metal case that it came in for an APAN charge :D ). When one of the hands (I did only with the hour hand, but it could easily be with both) gets to a certain position, it completes the circuit to set of the blasting cap. Voila! There you have up to a 24 hour delay accurite to the second.

<small>[ February 25, 2003, 08:01 AM: Message edited by: metafractal ]</small>

[jarrod]

I have the plans for an electronic timed “igniters” it looks fairly good although I haven’t tried it. Its from Anarchists cookbook so I’m not sure how reliable it is. It’s a simple ic timer based system. These are the parts listed

2 Switching Diodes (1N914) 276-1122 $0.99
10K Resistor 271-034 $0.19
Relay Switch (6V) 275-004 $2.99
IC Timer 555 276-1723 $1.19
Mini LED 276-059 $0.99
Electrolytic capacitor (Size depends on delay desired)
Resistor (Size depends on delay desired) $0.19
Push button switch (any model)
2 9-Volt Batteries (Cheap, but new ones)
Small piece of breadboard approx $1.00
24 gauge solid core insulated wire
Soldering tools
Solar Igniters (electric matches available at hobby stores)
Mini Alligator clips (roach clips

Compacter1 (in farads) x Resister1 (in ohms)
---------------------------------
6
= Time (in seconds)

you could use this to change your delay. I tried to post the plans but just wouldn’t work for me :mad: so if any are interested post your email and I will send you the full plans.

Oracal I am very interested in your system, due to cost effectiveness. If you don’t mind could you post your plans, because I’m not to good with electronics :(

thanx

<small>[ February 26, 2003, 04:59 AM: Message edited by: jarrod ]</small>

[Tuatara]

Be very, very careful if you try to use radio for remote det. No matter how good your encoding system is, there is always a possibility of random interference looking like a valid 'trigger' message. I used to work for a company that made military equipment - and I discovered the military don't like radio dets for this reason (we were asked to do a laser based remote det).

If you do go this route I suggest using a cheap microprocessor to decode the signal, but make your 'trigger' code really big (256 bits ?) to reduce the risk of getting blown to bits. Things like DTMF decoders are just not secure enough. Especially since one would only go to this much trouble for a fairly impressive crater :D

With a micro you could even put in a time delay so the det can't happen for a set period ('light fuse and get away')

As for cost: I have here beside me a micro based radio receiver that can be built for about US$10 or less, transmitter would be about the same price. Runs at 305MHz, range mostly determined by the antenna but unlikely to go more than 500m with 10mW

[Energy84]

Well where are the plans for this thing? Schematics, parts list, board layout plans???

[Jumala]

Two weeks ago I found a plan for a little amateur radio receiver.
It is a audion or direkt conversion receiver and uses only 3 J310 FET´s. This receiver has a good sensitivity and selectivity for the frequencies from 1,6-30 MHz. Frequency depends only on a single resonant circruit.
The receiver can be build for a available CB tranmitter or a more exotic frequency with an own AM transmitter.
With a DTMF chip and a time delay you can make a save remote system.
No DTMF signal occurs at 20 MHz accidental especially not for a longer time like 5 seconds (delay).
A other more save method could be to use two DTMF signals stored in two monoflops with an AND Gate to combine them.

I have ordered the J310 FET´s and will test the receiver.
The receiver parts cost approx. 5 bucks. If it works I will load the plan to the FTP page.

[Tuatara]

You mean you want me to give away my intellectual property? <img border="0" title="" alt="[Wink]" src="wink.gif" />

Actually its part of a vehicle alarm system I'm designing. When I have more spare time I might do a special design for this purpose, and upload to the ftp. Maybe I could sell kits to forum members to make things easier. Sorry I can't do free parts - I may have my own company, but it consists of just me at the moment, and I have to spend all my cash on annoying things like food.

Would there be much interest in a kit? (not trying to make millions here :D )

[Jumala]

@ Tuatara
Do you have a schematic for a direkt conversion receiver at approx. 400 MHz. Many cheap remote control units work at 433 MHz.
This frequency is to high for me because I have no equipment to measure anything at 433 MHz. The most important for me would be the measurement of the resonant circruit.
I can build this receiver only by try and error method.

[Tuatara]

Your best bet is to go here
<a href="http://www.micrel.com/product-info/qwikradio.shtml" target="_blank">Micrel Quik Radio</a>
These are single chip radio transmitters and receivers for frequencies from 300MHz to 900MHz. No tuned components!!! All they require is a quartz crystal to set the operating frequency. There are lots of application notes and reference designs to get you going. You should be able to get the parts from Digikey.

[A-BOMB]

Well for timed Dets I use the parts from a bathroom scent sprayer. I mean we have all seen those things up on the wall of a public or store restroom that spray a scent out at timed intervals. I just take them off the wall and remove the circuit board and the motor unit that presses down the the spray nozzle on the can. Most of these unit have a adjustable delay between firings(usually from 2 to 30 minutes) just take the wires from the motor to your detonators leads and turn it on. But you must be careful some units spray when you turn them on, so cross the wires then turn the unit on then test it with a voltmeter, then you can hook up the det. I like these units because there already premade, and free <img border="0" title="" alt="[Wink]" src="wink.gif" />

<small>[ February 27, 2003, 04:02 PM: Message edited by: A-BOMB ]</small>

[Anthony]

Tuatara, I'd be interested in a kit of your circuit, whether it be just a bare PCB, or a PCB and a complete bag of components.

It would be useful to me if it had two outputs - the main firing circuit with 5sec delay, and an auxilary output which went live as soon as the firing signal was recieved.

The aux output could be current limited to 50-100ma to prevent accidentally firing the detonator through miss-connection. The purpose would be to sound an electronic alarm/siren. So if at any point during setup you hear the siren, you know you've got &lt;5s to duck and cover if you're anywhere nearby.

[Tuatara]

Thanks Anthony. I could do PCB, PCB + parts, fully assembled and tested - whatever you prefer. I'd like some design input so I think maybe a new thread? This one could then remain devoted to systems built from OTC parts.