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. 26, 1995
Filed:
Jan. 25, 1995
Peter G Hancock, Plano, TX (US);
Honeywell Inc., Minneapolis, MN (US);
Abstract
A subcircuit for discharging a capacitor at a preselected rate incorporates a first transistor and a second transistor connected with the emitter of the first transistor providing current to the collector of the second transistor. The base of the first transistor is connected to a capacitor to be discharged at a preselected rate. The base current of the first transistor discharges the capacitor as a function of the base current provided to the second transistor. In order to provide a current of very small magnitude to the base of the second transistor, a plurality of lateral PNP transistors are connected in a plural stage arrangement in order to take advantage of the current dividing characteristic of lateral PNP transistors. A collector of one lateral PNP transistor is connected to the emitter of another so that each stage of the subcircuit reduces the output current by a very precise ratio.