Chrysler Corporation

Walter Joseph Campau

Frederick William Crall

Lawrence William Tomczak

LaVerne Andrew Caron

La Verne Caron

A variable inductance transducer for providing, via inductance modulation, an electrical output signal which is representative of a mechanical input signal. The transducer comprises a cylindrical plastic bobbin on which an inductive coil is wound. A pair of electrical terminal receiving sockets for a pair of electrical terminals are formed at one end of the bobbin and a pair of electrical terminals are disposed therein. The ends of the wire forming the coil are soldered to the terminals. A protective enclosure is molded around the coil and the portions of the terminals received in the sockets to enclose the coil and lock the terminals in place in the sockets. A ferrite core is slidably arranged within a central axial bore in the bobbin to vary the inductance of the transducer in accordance with the axial portion of the core. The core is selectively positioned by means of an actuating mechanism including a flexible actuating member and in one disclosed embodiment the actuating mechanism is a vacuum servo while in another disclosed embodiment, it is a formed wire rod. The transducer is of reasonable cost and possesses accuracy, repeatability and response which makes its usage in an engine spark timing control system significantly advantageous.

Method of calibrating variable inductance transducers

A variable inductance transducer for providing, via inductance modulation, an electrical output signal which is representative of a mechanical input signal. In a preferred embodiment the mechanical input signal is the intake manifold vacuum of an internal combustion engine and the electrical output signal is utilized in an engine spark timing control system to adjust the spark timing in accordance with the intake manifold vacuum. The transducer comprises an actuating mechanism in the form of a vacuum servo which axially positions a ferrite core within a central axial bore of a plastic bobbin on which an inductive coil is wound to thereby vary the inductance of the coil in accordance with the vacuum applied to the servo. The bobbin and coil are enclosed in plastic to form a separate unit which is assembled into the transducer by being controllably lodged within the bore of a molded plastic element forming a portion of the body of the transducer. The transducer is calibrated by the controlled lodging of the unit within the bore of the molded plastic element.

Variable inductance transducer combined assembly and calibration method

A variable inductance transducer for providing, via inductance modulation, an electrical output signal which is representative of a mechanical input signal. The transducer comprises a cylindrical plastic bobbin on which an inductive coil is wound. A pair of electrical terminal receiving sockets for a pair of electrical terminals are formed at one end of the bobbin and a pair of electrical terminals are disposed therein. The ends of the wire forming the coil are soldered to the terminals. A protective enclosure is molded around the coil and the portions of the terminals received in the sockets to enclose the coil and lock the terminals in place in the sockets. A ferrite core is slidably arranged within a central axial bore in the bobbin to vary the inductance of the transducer in accordance with the axial position of the core. The core is selectively positioned by means of an actuating mechanism including a flexible actuating member and in one disclosed embodiment the actuating mechanism is a vacuum servo while in another disclosed embodiment, it is a formed wire rod. The transducer is of reasonable cost and possesses accuracy, repeatability and response which makes its usage in an engine spark timing control system significantly advantageous.

Growing community of inventors

Grosse Pointe Woods, MI, United States of America

Walter Joseph Campau