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. 04, 1976
Filed:
Apr. 21, 1975
Applicant:
Inventor:
Chao S Chi, Shrewsbury, MA (US);
Assignee:
Digital Equipment Corporation, Maynard, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
3072 / ; 3072 / ; 328147 ;
Abstract
A zero-crossing detecting circuit where the input signal is applied to positive and negative threshold circuits. Each threshold circuit is connected to the input of a respective one-shot circuit which responds to the beginning edge of each output signal from its threshold circuit. The output pulses of both one-shots are applied to a NOR circuit which thereby responds to the beginning edges but not the trailing edges of the signals from the threshold circuits. Accordingly, variations in the trailing edges of the signals from the threshold circuits due to hysteresis or varying propogation times do not effect the circuit's output.