Cheap remote detonation

[green beret]

I havent tried this but theoretically it should work.
At supermarkets and hardware shops, one can obtain wireless doorbells. The one I had a look at today cost $26 ran on 12v and had a range of 70m. Its a little too expensive to use for a disbosable but a person could use it for small projects. Can anyone see why this wouldnt work/is impractical.

[nbk2000]

$15 gets you a 100 yard spool of 2 conductor wire. So, unless the range is greater then the cost of a similar length of wire, then there's not much point in it.

[green beret]

Very true. Although if you just wanted to fire the charge and get out of there without bothering to wind up 100 yards of wire it could have its uses, assuming fuse isnt an option and precise timing is needed.

Im going to steal one of these devices, it would be a novelty to be able to press the button and...BOOM.

[Arthis]

Anyway you need to press the button... ;)

The problem would be in re-buying one every time. Unless we find something cheaper, I don't think it will be used. But stealing a box of them would be great. I dream about raiding a supermarket/ardware store.

The main interest would be in diverting people while doing something else.

[green beret]

Yeah, If they were reusable it would be alot more viable to buy one. Stealing a heap would be good because they would be totally disposable, and I like the idea of not having to wind up 100 feet of wire when the cops are coming. :D

I'll see if I can "obtain" some.;)

[Desmikes]

I've never seen any of these devices in action, but I am assuming that it's a button that can be placed up to 70m away (i'm impressed) from the ringer that would brobably be battery powered. If I am correct on understanding how it works then you wouldn't have to buy a new one every single time. Why not just extend few meters worth of sacrifice wire from the ringer and then "make it ring" just make sure that the ringer is far enough to withstand the blast, you can even enclose it in a protective case just to be sure.

[nbk2000]

I had the thought of using something to press a door bell ringer while you were on the other end of the house. They go to check the front door, while you're coming in the back. SURPRISE! :D

I'd think it terribly funny if you used a remote control door bell to remotely ring someone elses door bell. :)

Indeed, you could use a length of wire to distance the R/C from the explosion, thus making it re-usable.

[GibboNet]

Desmikes, you've got the right idea, just extend the wire from (what was) the speaker to your device, making sure the wire is long enough to allow the unit to be out of the blast. Maybe just coat it in silicon or something else rubbery, so whether it gets shocked or not, it shouldn't be damaged, as it won't be too close anyway.

However, I seriously doubt they would work at 70m ! That's a fair way seeing as most of them are designed to work from one side of the door to the other, which is less thana metre. I had a look at some in a local hardware place (can't get to a large chain store), and the maximum range was 20m. You might have found a good brand at 70m.

If the reciever end was very simple, could you replicate it with some home electronics ?

I'm thinking they could be very useful after all, though it may be harder to go and collect the unit at the explosive end, than just roll up wire from where you were based. (It may hev been thrown a fair distance from the blast, depending on the legth of wire)

If it does work, it would at least be cheap, whereas I'm paying nearly $1 a metre of twin cable. :(

[Arthis]

Buy your twin cable in larger quantity (buy 100 m at once) and it'll be cheaper.

The electronics in the receiver is not really easy to copy, because microchips are used, and it will most likely be too expensive to buy one, moreover you will need to encode the chip, etc. The time and material to make one wouldn't be worst the 20$.

[green beret]

Yeah thats what I was thinking too (about the sacrifice wire). I am 100% certain it said 70m. It had a picture on the packet of a mansion with a long drive and the button at the gate and the reciver at the house. If I do get one I'll test it and let you all know.

I like youre idea NBK but you would have to be sure there was only one person in the house, otherwise you wouldn't know where the other people were in the house.;)

[Desmikes]

The signal on those things must be able to travel thru walls/metal/wood/concrete in order to be effective, that means that not only should you be able to cover it in rubbery substane but also put it inside a large brick (metal case would significantly reduce operational range)

[Anthony]

I bought one of these a little while ago for £8.99. They're designed so that you can carry the ringer unit about with you, so rangewise it will go from your front door, through your house and into the shed at the bottom of your garden, for example.

I never used mine because the "speaker" was a piezo buzzer with no useful/significant output. It'd probably require an amplifer splicing into the circuit before the buzer driver, operating a transisitor then possibly a nice chunky relay.

[Desmikes]

I was gone for several days so I didn't post this before this topic was gone, but I had this idea that would appeal to people that don't wish to be anywhere near charges when they go off. Instead of using remote door ringers, how about hand-held radios? A-ha, those babies will work from up to 4km away!!! they are not very expensive either. In order for "call" function to work it would have to jump the voltage quite a bit and if that is not powerful enough you could always set up another more powerful blowbox that would be triggered by the radio

[GibboNet]

The problem with these, (as with the door ringer, but much more so) is that so many people use them, and the frequencies close to them, that vhances are someone will use theirs in range of your experiment, possibly while you're setting it up, which means it goes off prematurely on their signal.

You may end up with it going off while you're holding it or something, which is really not good.

[blindreeper]

I was in the harware store yesterday and thought I might drop in and check these things out. I found one with 100m range and 8 differnt ring tones (surely onbe of them would be usefull) but one of these would set me backm $110 :eek: fuck that. There was 25m ones for about $25 and 50m ones for about $50. It seems you pay a dollar per m of range. But I think I may adventually invest in a 100m one as 100m is a fair distance. If you are in no hurry these would be good, no cords to carry or anything messy like that. And 100m is good enough for a 10kg ANFO as demonstrated by spydamonkee :D

[Desmikes]

Is the value of australian dollar similar to american dollar? $100 for 100m range!!! That's rediculous I can buy a pair with 10+ channels with 3km range (in open field) for $25 (amer. dollars). I wasn't aware of interference between devices, i live in the very small town and I never had this problem, but I suppose this would be a major problem if you were in the populated area. Actually, if you WERE in the populated area than law enforcement will get you before premature ignitioin will :rolleyes: .