Make a cheap electronic detonator!

Step 4 Optional

Of course you could have used the timer if you wanted to make a count-down detonater... and instead of an alarm at the end of the relay, how bout an explosive?

Get some nichrome wire, and thread it through a safety fuse, and connect the wire to the relay, for a more detailed how-to on electrical igniters visit UN: http://unitednuclear.com/wire.htm

Comments

[gedion4000]

I have a timer much like this one but when the alarm goes off it beeps, its not a continuous sound, will the current from the short beeps be enough to activate the relay? or does it need to be constant. i want a count down timer to power a relay to fire off a confetti cannon. i was hoping to use an electromechanical relay for its looks, but is there another one that might work better?

[matt]

If your sound input is not continuous use a latching relay. This is essentially a flip-flop and a relay combination. Did you already buy relays?

[gedion4000]

no i haven't gotten relays yet. i had actually looked at the latching relay option late last night. from what i can tell you need the charges to be reversed in order to turn it off again, any suggestions on that aspect? i was also not sure of how much input they typically need to switch. the alarm i currently have sweeps from .45 volts to .27 volts. about every second or so, but it beeps really fast so i think my meeter is a little to slow to get a super accurate reading.

[matt]

There are many relays available. If you cant find one that has a very low turn on voltage, then buy a transistor with a low threshold voltage, or a low voltage relay. And have it connect a source that has voltage high enough to trigger your latching relay. Then your circuit will look like this: Timer signal--> transistor --> latching relay Yes reverse voltage is needed to switch the latching relay. But for your application, a one time firing confetti gun, nothing matters after its been fired. Just disconnect the power to the circuit and then use it again.

[jpoopdog]

heres a better idea, use a signal relay, with the source current (the sound output), passing through a low current high voltage (e.g A23, 12v) battery. signal relays can turn on high voltages with extremely low currents, such as mine which can turn on up to 15V 5A, using a current at least 5V 5ua (thats the next lowest form of miliamps), which is 0.005 or so miliamps. i have tested this instructable with my signal relays and they work fine, i also discoverd, with my cheap digital alarm clock, that on the microprocesor, or whatever the long black thing with all the pins has (i forgto the name), i remember if i shorted the first and second pins on one side while the alarm went off, or begun it with shorted, the alarm beep would be contant, and oddly become increasingly loud also, but only for 20seconds before it stoped.

[gedion4000]

thanks Matt, i didn't think about using a transistor to fire the relay, ill have to work something out like that if i cant find the right latch. i will also have to figure out some kind of switch to reverse the voltage, the cannon needs to be reset within a few minuets to be used over and over again

[matt]

Heres an idea for the reset switch: From your battery source run a line, that goes through a push button, and a diode to your relay (make sure its reverse polarity). Then the button will be used to reset it. Also put a diode on the output from the transistor. The diodes will prevent the reverse voltage from going into and damaging your transistor and your power source. Good luck, let me know how you make out.

[gedion4000]

thanks, ill let you know how it goes.

[russiankid]

well in the picture u dont have a seprate battery for the higher voltage of the personal alarm and that that doesnt look like relay can u help out

[e-vad]

ok.. i am kinda new to this stuff. and i have worked with some basic wiring but when it comes to a relay i have no clue, so could some one maybe make an instructable or just tell me where to hook the wires up and where they are coming from.

[matt]

Check out this http://www.howstuffworks.com/relay.htm

[Toni the rocketman]

yeah,where!?

[Demented]

What am I supposed to detonate actually? And where do I hook up the wires of the explosive?

[nkk07]

its not HOW TO MAKE A BOMB instructable work it out for yourself