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:
Sep. 13, 1994
Filed:
Dec. 22, 1992
LaVerne A Caron, Kalamazoo, MI (US);
Edward F Handley, Kalamazoo, MI (US);
W Paul Kuo, Kalamazoo, MI (US);
E James Lane, Highland, MI (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A solenoid driver applies an actuation current to a solenoid for a predetermined period and a lower holding current thereafter. A switching device pulses the applied current within upper and lower limits to maintain the actuation and holding current amplitudes, the pulses being integrated by solenoid inductance into a substantially steady-state current. A multiprocessing unit determines the amplitudes of solenoid current. A signal representative of desired current amplitudes is compared with a signal representative of measured solenoid current, and a signal representative of the difference therebetween is used to control the switching device. Voltage developed across a resistor in series with the solenoid is input to a differential amplifier having connected to its output a peak detector that mimics the decay rate of current in the solenoid, the signal representative of measured solenoid current being obtained from the peak detector. Power dissipation by the solenoid driver is minimal, and the latter is capable of withstanding a continuous short to a source of electric current. The output of the peak detector is monitored by the microprocessing unit for the detection and logging of faults.