How To Build Electronic Timers For Explosives
Timers:
Timers for explosives are much more readily availible now than several years ago. The watch companies have seen to this To make a simple timing device all you need is any digital watch with alarm and some wire. Digital watches with alarms are the perfect timer for a bomb. They can be modified very easily. To do this, simply open the watch and disconect the buzzer. Solder some wires to the buzzer leads and you are all set. This devise must be conected to a primer.
Primers:
Primers are a small explosive devise to set off a larger explosion. An example would be an atomic bomb used to detonate a hydrogen bomb. The primers I will be discussing are for much smaller devises though.
You will need these parts:
- Timer
- 6-12volt battery
- Low volt coil relay
- Solar egniter.
Construction:
Take the timer and solder the buzzer leads to the coil of the relay. The relay coil must be below 1.5v,.02amps. These are availible at any Radio Shack store.
Wire the battery in a curcuit with the relay and solar egniter. The solar egniter should be the type used in model rockets. Set the timer alarm to go off whenever desired. the solar egniter can the be inserted in many types of explosives such as plastique, dynamite, m-80’s or the like. The solar egniter provides enough of an explosion to set these substances off. Since you never want to be around when an explosion goes off, this is a very easy way not to be there.
Note: This devise is never intended for actual use! This information is merely for your personal knowledge.
“solar igniters” CANNOT set off plastic explosives or dynamite, and do not provide an explosion of any sort. They just get hot, melt a bridge-wire and ignite a small bead made from something similar to black powder paste.
Also, the driver circuit for the watch’s piezo element cannot source enough current to drive a relay. You first need to take that signal, rectify it use that steady DC voltage to control a transistor switching circuit. That circuit itself can then control an SCR (a solid state switching device that can handle high current) which is more than beefy enough to switch current from the igniter battery to the igniter itself.
Don’t forget, most watches will “beep” in confirmation when the time is set, so you shouldn’t connect the switching circuits until AFTER that point.
The advantages of SCR switching are that they have a wider range of operating temperatures, they have no moving parts, and they are not sensitive to vibration. Of course, you will need to teach yourself a little about electronics but if you don’t want to do that, best stick to mechanical timers.
It’s a good job this “devise” is never intended for actual use, because never in a million years would it actually work.
You need a transistor/SCR switching circuit between the watch’s piezo element driver and the relay, and solar igniters are far too fragile to be of any real use outside of model rocketry. Get some proper e-matches or make your own hot-wire igniters. Much cheaper when bought in bulk, and if you run your firing circuit off a racing battery pack you can bang enough current down them to get away with using thicker wire (so it won’t break).
For PE or dynamite, nothing less than a proper detonator (home-brew or not) will do. A solar igniter won’t do a damn thing, and the worst a hot-wire igniter would do is set it on fire. It’s all about having the right tool for the job, folks!