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:
Jun. 25, 1985
Filed:
Feb. 17, 1983
Robert Buck, Neukirch, DE;
Michael B Friedrich, Kressbronn, DE;
Hans D Gesthuysen, Essen-Kettwig, DE;
Gerd Marhofer, Essen-Bredeney, DE;
i f m electronic GmbH, Essen, DE;
Abstract
A contactless motion detector, specifically an oscillator whose signal amplitude is attenuated or enhanced by the approach of a monitored metallic element, is periodically switched for brief periods into its alternate state by a train of short test pulses giving rise to corresponding checking pulses that are superimposed upon the integrated output voltage of the oscillator whereby that voltage is intermittently increased when at low level and/or intermittently reduced when at high level. These checking pulses, whether of the voltage-increasing or the voltage-reducing kind, are integrated to provide an enabling signal allowing a controlled load to be energized or de-energized according to the mean value of the output voltage; an absence of the enabling signal indicates a malfunction.