Fri, 22 May 1998 23:08:37 +0000
> Date: Fri, 22 May 1998 20:20:26 -0400 (EDT)
> From: email@example.com
> Subject: Re: [AMPS] parasitics
> To: firstname.lastname@example.org
> >Nobody has come up with a real explanation of how the forces necessary
> >to bend a filament are generated, applying the same principles as an
> >electric motor.
I posted the force levels about six months ago, when a discussion
about filaments breaking from current and magnetic fields was posted.
The worse case total force from filament wire to filament wire was
7.65 grams for thirty amperes in a 572B filament.
To put this in perspective, consider the "great forces" in a meter
movement. A single turn winding takes dozens of amperes to produce a
few grams of torque against a very strong field magnet. It takes a
a lot of ampere-turns in a close area with a very dense field
(generally concentrated by an iron core) to get strong forces.
Try to build a motor with air core coils, and see how well it works.
Now consider what the tube looks like.....
73, Tom W8JI
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