Induction heating to light fuse

Uhhh....what are you thinking of making with a remote fuse? I don't like how this sounds....not at all.

lol, do not fear, I'm a model rocket fanatic. I've recently come across some retro style fuse ignition rockets. Of course I could light the fuse off with a lighter, but I would rather do it remotely for safety. Like I said, these rockets are old and probably dangerous. Any help would be much appriciated.

Need Help! said:

I'm trying to find the best way to remotely set off a fuse. I've considered nichrome wire, but I've also been taking a second look at using induction heating. is this possible? thanks

Click to expand...

Induction heating is pretty complicated. You need driver circuits and the right frequencies, etc. Either use nichrome wire, or wire from an old toaster. You could even use a small neon sign transformer. If you put the fuse in the gap between the leads, when the transformer is energized an arc will jump the gap igniting the fuse. Nichrome is probably the simplest.

Thank you, I thought that the nichrome would be the best way, but I wanted to explore my options. Could copper be a good substitute for nichrome? I've done experimenting and found that with the right resistance, copper gets pretty hot. I'm new to all of this, usually the rockets I set off are simply set on the launch pad and flip the switch, you know? lol

Need Help! said:

I'm trying to find the best way to remotely set off a fuse. I've considered nichrome wire, but I've also been taking a second look at using induction heating. is this possible? thanks

Click to expand...

Inside lamp cord is many strands of very fine wire, maybe #40, and this melts at small currents, maybe 5A or less.
It would help if you measured the diameter of this strand; to do that wrap 10 or 20 or 50 turns around a pencil with each turn touching the one before, measure the length of the winding and then divide by 10 or 20 or 50.

Get a few inches of a single strand of this wire and pass current through it from a 1.5v cell or a 9v cell. With 120vac the wire will melt so fast it will appear to explode and it may not light the fuse. A 12v car battery may also work, with current limiting or without. Current limiting is another post.

Keep track of how long a strand you used. The longer the strand the longer it will take to melt at higher voltage.

This will take some experimentation. You may want to wrap the wire around a matchhead and the fuse, or just the matchhead, to start.

Wear eye protection.

This is certainly not from personal experience or anything.....lol.....but a short piece of phone wire (24 gauge) wrapped around said fuse a few times, and energized with 120 volts will do the trick.

Simply wire a switch in series (in a box) with a cord. Wirenut the phone wire to the end of a cord, plug it in, hit the switch, POOF!

Of course, I've certainly never done such a thing...wink wink... but the above will also set off flashcord, and in turn, as much dynamite as needed to accomplish the desired result. Usually the removal of rock, or maybe a tree stump.

Rob

"Using [the] Onderdonk equation", 10 mil dia. nichrome will reach ignition temp. in 5 seconds and melt in 10 seconds with 5A going through it, in free air.

4" of this wire across a 1.5v battery should do it, with the battery disconnected before your 10 sec. is up.

Awesome. I plan on placing a match head at the end of the fuse just to have a sure ignition. Thanks for all the help.