Throw Coils
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 Packard PR340 DPDT 24 Volt Coil Switching Relay Sale Price: $4.00 Eligible for free shipping!Availability: Usually ships in 1-2 business days |
 Graham Professional Cellucotton 40 Ft. Box Sale Price: $4.39 Eligible for free shipping!Availability: Usually ships in 1-2 business days |
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 Throw Streamers - Neon Cresey -Coil / Stage Magic |
 Throw Coils - WHITE - LARGE #10 - Streamer Magic T |
 Ceramic Design, Library Binding, 1963, A Chilton Book, Sale Price: $16.00 Eligible for free shipping!Availability: Usually ships in 1-2 business days |
 3 pc Speaker System Sale Price: $64.98 Eligible for free shipping!Availability: Usually ships in 1-2 business days |
 Pioneer TS-W3002D4 12 In. Champion Series PRO Subwoofer with 3500 Watts List Price: Sale Price: Too low to display Eligible for free shipping!Availability: Usually ships in 1-2 business days |
Mylar Throw Coils Silver (#10) by Uday
How Coil Guns Work
What is a Coilgun?
Coilguns are linear electromagnetic motors that are capable of firing projectiles with ferromagnetic properties (this basically means they are attracted to magnets). A pulse of current is delivered through the drive coil creating a magnetic force pulling the projectile forward. The current pulse is timed so that when the projectile reaches the middle of the drive coil, the pulse turns off allowing the projectile continue forward at significant speed.
Disadvantages of coil guns
There is virtually no limit to the speed at which a coilgun can throw a projectile, so why aren't we using them? The catch is that today's coil guns can only throw projectiles at very limited speeds due to the extreme difficulty of engineering coil guns. It is extremely hard to time the current pulse through the drive coil just right so that the projectile is not slowed down by magnetic force after it reaches the center of the coilgun. Also, eddy currents through the projectile can make the projectile an electromagnet itself and repel the drive coil severely limiting the efficiency of coil guns.
Solutions to the disadvantages of Coil Guns
The length of the pulse through the drive coil (often produced by a capacitor) can be adjusted by using the right type of capacitor, and fine tuning the inductance by adjusting the number of turns of wire on the drive coil. There have been many proposed solutions to the eddy current problem, one solution is to put slots through the projectile to make it harder for eddy currents to form, another is to make the projectile out of a metallic powder encased in a resin coating making it nearly impossible for eddy currents to form.
Conclusion
Coil guns have the potential to become very useful tools or even weapons in the future. Despite their disadvantages, it can be a fun DIY project to build a coilgun at home. With the way that technology is progressing it should not be long until coil guns are practical and available.
Diagram of a Coilgun:
www.coilgun.eclipse.co.uk/images/basic_coilgun_images/simple_reluctance_launcher.jpg
About the Author
Matthieu Miser
http://railgundesign.blogspot.com
