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:
Mar. 13, 2001
Filed:
Feb. 02, 1998
Michael F. Gallavan, Edmonds, WA (US);
Fluke Corporation, Everett, WA (US);
Abstract
An automatic power turn-on circuit for a battery-powered measurement instrument. Instrument power is normally off, and when the instrument is connected to a voltage to be measured, the voltage that is sensed activates an electronic switch that in turn connects an internal battery to the processing and display circuits of the instrument. The voltage sense circuitry includes circuits for sensing either a positive or a negative voltage, and biasing a driver transistor into conduction. The driver transistor in turn activates the switch to connect the battery voltage to a power supply output node. An RC network holds the switch in the “on” position for a short period of time after the voltage to be measured is removed from the inputs of the instrument.