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. 23, 1989
Filed:
Jan. 13, 1988
Gary W Kaibel, Troy, MO (US);
Frederick F Schweitzer, Watertown, NY (US);
Sherwood Medical Company, St. Louis, MO (US);
Abstract
A fail-safe circuit is disclosed for use with an intermittently operated d.c. motor connected by means of a circuit breaker to a power supply, wherein a control circuit provides control pulses intermittently to the motor. The fail-safe circuit includes a capacitor which is charged when the drive pulses are being applied to said motor, and is discharged when the drive pulses are not being applied to said motor. A reference voltage is generated and compared with the voltage stored on said capacitor. When the voltage on the capacitor exceeds the reference voltage, the circuit breaker is caused to interrupt the power supply to the motor.