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:
Apr. 16, 2002
Filed:
Dec. 29, 2000
James R. Egnot, Melbourne, FL (US);
GE-Harris Railway Electronics, LLC, Melbourne, FL (US);
Abstract
A method for performing an “AND” operation on two independent inputs in a fail-safe manner includes cascading two charge pumps to output a condition signal representing the “AND'ed” state of the inputs. Each independent input has an active state asserted by a waveform of predetermined frequency and duty cycle, and an inactive fail-safe state asserted by a zero voltage. The method includes supplying power to a first charge pump, supplying power from the first charge pump to a second charge pump, and supplying each of the independent inputs to one of the respective charge pumps. A condition signal is output using an output from the second charge pump. Additionally, the method verifies the correctness of the frequency and duty cycle of each independent input using a cross connection scheme. This method provides a high-power, low-loss, and low-cost electrical circuit for operating devices responding to specific voltages, for example, vital relays.