Construction of a Timed Electronic Detonator

Construction of a Timed Electronic Detonator

by Ziggy

This essay will explain the procedure of construction of a timed electronic detonator. This contrivance is inexpensive to and easy to build. It is very simple. It would have to be, with the help of a book from Radio Shack, (Understanding Solid State Electronics, Texas Instruments Learning Center) I designed it. The device’s components can be easily obtained at almost any local department and/or hardware store. Any terms not commonly known will be explained. Also follow all directions to the exact and steps in order. Any deviation from may result in the device’s failure.

Before you begin construction, you will need to obtain all the necessary tools and supplies. You will need the following:

1. One basic electronic kitchen timer (Fig. 1). This can be found in the house wares section of almost any department store. It should have time set and start/stop functions, a power supply of at least 3 volts (basically 2 AA batteries), and preferably an LCD (Liquid Crystal Display) screen.

2. Batteries necessary to power timer.

3. One solar fuse (Fig. 2). These can be obtained in packs, at some hobby shops, but are most commonly found in model rocket engine kits, carried at most department stores. They are basically two small gauge wires connected by an amount of mercury fulminate, a flammable chemical compound, with a very low ignition temperature. When electrified this circuit will quickly reach breakdown temperature and combust violently.

4. One nine-volt battery.

5. One nine-volt battery connector.

6. One low-voltage transistor (Fig. 3). If you cannot find them at your local hardware store, they are guaranteed to have them at Radio Shack. A transistor is a circuit that, in this application, will be used as a switch. It is activated by a small amount of electricity. No certain size is needed. Just ask for the smallest one they carry.

7. A roll of wire, no larger than sixteen gauge.

8. Wire connectors of the appropriate size.

9. A roll of electrical tape.

10. A wire tool that has stripper, clipper, and crimper functions.

11. Small Phillips and flathead screwdrivers.

12. An X-acto knife.

Now that you have all your tools and supplies, it is time to begin construction. First take the timer and, making sure there are no batteries in it, with the appropriate screwdriver, remove the back cover. You should see a speaker connected to a circuit board by two wires. With the wire tool, clip the wires as close to the speaker as you can, and strip the wire ends. Be careful, the wire connections at the circuit board are easy to break.

Throw the speaker away. Now take the back cover and use the X-acto knife to bore a hole about the diameter of a pencil through it. Take the roll of wire and cut two seven inch long lengths (you can remove excess later), strip all the ends , and put them both through the hole in the back cover. Using the wire connectors, connect one wire to each of the wires coming off the circuit board that were attached to the speaker of the timer. Guiding the wires, replace back cover. The wires should be connected to the wires from the timer and come through the holes in the back cover.

I will now refer to these wires as “the timer wires” Cut two six inch long lengths of wire from the roll, strip the ends and connect them to the outer legs of the transistor. Be careful, the transistor is fragile. Next, connect one of the timer wires to the middle leg of the transistor. It does not matter which. Connect one of the wires running from the outer legs of the transistor to one leg of the solar fuse. Once again, it does not matter which. Be careful when working with solar fuse, it is very fragile. If you can, keep it in the tape it comes wrapped in. That will make it easier to handle and less likely to break. Connect one of the wires from the nine-volt battery connector to the other leg of the solar fuse.

Next, twist together the remaining timer wire, the other wire from the nine-volt battery connector, and the wire from the other outer leg of the transistor. Clamp in wire connector or wrap in electrical tape. Consult Fig. 4 to make sure of all your connections. Insert and connect batteries.

If you followed the directions properly, when the timer goes off the solar fuse should ignite. You can use this gadget to detonate anything from fireworks to an I.E.D (Improvised Explosive Device). If the solar fuse does not ignite, check your connections and replace the solar fuse. This is a one-time use only device. If you use parts over they might be damaged. If a malfunction due to damaged parts occurs, you may be injured. Above all, be careful.