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:
May. 01, 1979
Filed:
Sep. 01, 1976
Robert A Ziemke, Sandusky, OH (US);
James D Heckelman, Norwalk, OH (US);
Dan-Mar Co., Huron, OH (US);
Abstract
A homing system utilizing a loop antenna positioned at approximately 45.degree. to the vertical to provide an electromagnetic field having both horizontal and vertical components. These signal components are picked up by a vertical loop stick antenna alternately connected to one of two bifilar wound coils of a horizontal loop stick antenna to provide alternating signals. The strength diagrams for the alternating signals are cardioid shaped and are arranged back to back with their null point passing through the intersections of the back to back signals. The null point of both antenna systems occurs when the horizontal loopstick antennas are at right angles to the electromagnetic lines of force; and any time that the horizontal loop sticks are turned at an angle relative to their null point, a difference in signal strength exists between the two antenna systems. This is picked up, and is amplified at separate time intervals by a common amplifier. The separate signals are detected, than thrown on the opposite sides of a reference voltage and filtered to give a signal, the polarity of which is indicative of the side of the null point to which the antenna is positioned and the strength of which is indicative of the amount of deviation. The signals are passed to a stepper motor which both rotates the antenna towards the sending station, and steers the driving motor for bringing the vehicle to the transmitting station. A unique automatic gain control is utilized to overcome the great difference in signal strength that exists in the 1,000 foot range adjacent to the transmitting station.