Patent ID: 9562840
Date: 2017-02-07
CPC Classifications: G01D,G01N

Claim:
1. A reciprocating bob viscometer having A. a mechanical structure including: B. the control circuitry including: the improvement comprising: said driving current is a digitally generated near resonance frequency sinusoidal signal where the sine wave is defined by:  where “R” is the peak voltage, “y” is the instantaneous voltage signal amplitude, “t” is the time and “f” is the frequency with a DC voltage level of Y; said peak voltage R being determined by:  where t wherein said peak amplitude for said period of said sinusoid signal is processed in said controller to determine the position of said ferromagnetic bob in said sample well; wherein roles of said first coil and said second coil are reversed using a coil selector when said ferromagnetic bob has travelled far enough in said first direction in said sample well; and wherein said first and second coils have a resonance circuit therein to act as a natural amplifier because operation thereof is near the resonance frequency.