PSN-L Email List Message

Subject: Re: HS-10-1 questions
From: "Andreas Tschammer" psn@............
Date: Sat, 1 Dec 2007 22:11:41 +0100

I received the manuals. Thank you Jack!

I did the test with the resistive bridge again with and without damping
resistor attached. I was not able to confirm the resonance at 1 Hz (but one
at abt. 24 Hz).
There was always a nonsinusoidal response to a sine current into the main
coil. This alone is not good I would say..

I also injected a sine current (40 uApp, 0.5 Hz) via a 100k resistor into
the main coil and watched the resulting sum signal with an amplification of
100 on the scope.
One should expect a sinosoidal signal since any superposition of two sines
results in a sine, but it looked very similar to the signal from the bridge.
The movement of
the mass was max. +/- 0.1 mm and barely visible.
Here the scope screen of the injected current (sine curve) and the sum of
the current into the
resistance of the coil plus the induced voltage from the moving coil:

I also turned the period vernier from its lower to upper limit in 1/4 turns.
There were jumps in amplitude during this. I would expect a steady change in
ampltiude while
turning the vernier.



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