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Chronograph spikes

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LAN_403

rp181

Sun Nov 23 2008, 07:23PM

Registered Member #1062 Joined: Tue Oct 16 2007, 02:01AM
Location:
Posts: 1529

For my coilgun, i have chrono'd it several times, and every time, i get 3 "spikes". Why is there three? I have been using the second 2 to measure, but whats causing the first spike?

I am using an IR/photo transistor setup, 5.3" away. The projectile is 1" long. Could the magnetic field be causing this?.

Avi

Mon Nov 24 2008, 06:48AM

Registered Member #580 Joined: Mon Mar 12 2007, 03:17PM
Location: Melbourne, Australia
Posts: 410

looks like it. Maybe try a less sensitive circuit or make the input lower impedance

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