PSN-L Email List Message

Subject: Springs again
From: "Paul Cianciolo" Paulc@........
Date: Tue, 17 Jul 2007 12:07:36 -0400

Hello Folks,

I have been building a vertical sensor for the past few weeks, doing lots of

It seems that the longer the spring, the longer the period... As a rough
rule of thumb.
I also remember Chris explaining about a "Zero Length" spring.

My vertical sensor is the type with a lever arm that is 26" long with a mass
at one end.
The other end of the lever arm has a pivot point about 2" from the end, and
a spring on the end to a base plate.

This arrangement certainly not a new idea, is new to me.,
This arrangement yields a 1.1 approx. sec period.
By careful adjustment of the pivot point and spring location, I can vary the
period and the mass needed to achieve balance.

2 questions.

1) What is the relationship between spring position, pivot location, and
mass weight.
As I would like to try to optimize this design , if indeed this is a valid
path to follow.

2) If a rule of thumb....the longer the spring, the greater the period,
within the obvious constraints applies.
 Has or why not has a vertical sensor been tried with a watch spring,
mainspring,  arrangement been tried.

Sort of a torsion spring, but one with many turns and greater length.
Perhaps my assumption that the main spring arrangement equates to a longer
spring is faulty?

Please comment

Thank You

Station VLF in Connecticut.


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