Date: Wed Feb 14 16:19:39 2007

Author: Jerry DiMarco

Subject: Re: Incandescent Bulb Destruction and Uses

I have a few questions before I hazard a guess. Does the magnet
force you to change the method used to open the switch? Is the bright
flash from the arc or the bulb? What was the intended result of this
modification? Thank you...


At 09:41 AM 2/14/2007, you wrote:
>From: WC Maddox
>If you have a large horseshoe magnet and a setup
>like put the
>switch contacts between poles of the magnet. When you jerk open the switch
>you will get a bright flash. If you use 15 or 25 W bulbs the filament is
>sometimes burned out. If anyone knows what is happening, Dr. Williams at
>Auburn would like to know. He came up with this modification of time delay
>experiment. It is more than the discharge of the energy stored in coil and
>V=-Ldi/dt. The bulbs don't burn out if you don't use magnet.
>End Message


Jerry DiMarco
Manager of Lecture Demonstrations and Instructional Labs
Montana State Univ., Physics Dept.
Bozeman, MT

Our Motto: "What would your mother do?"