The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 06, 1993
Filed:
Jan. 27, 1992
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A detection apparatus for detecting a dielectric constant of fuel having an electrode disposed in a fuel passage and applied with an excitation signal, a monolayer-wound coil disposed in the vicinity of the electrode so that fuel is introduced in a space between the excitation electrode and the coil, a phase comparator which receives the signal to be applied to the excitation electrode and a signal induced in the coil to thereby compare the signals. The phase difference between both signals is detected using a low-pass filter to output the d.c. signal component of an output signal of phase comparator, a comparison integrator connected to the low-pass filter to output a controlled output signal so that the phase difference between the excitation signal and the induced signal in the coil becomes 90.degree., and a voltage controlled oscillator connected to the comparison integrator so that the frequency of a signal, to be applied to the electrode, of the voltage controlled oscillator is changed depending on the output signal of the comparison integrator. The dielectric constant of the fuel is detected on the basis of a voltage output signal from the comparison integrator, or a frequency output signal from the voltage controlled oscillator.