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:
Jul. 29, 1980
Filed:
Oct. 13, 1978
Dennis L Lambert, Bothell, WA (US);
Paul R Lantz, Seattle, WA (US);
John Fluke Mfg. Co., Inc., Mountlake Terrace, WA (US);
Abstract
A converter that provides an analog (voltage) output signal that denotes either the period of an unknown low frequency signal or the ratio between the periods of two unknown low frequency signals is disclosed. The converter includes a ramp generator having a capacitor that is alternately charged in accordance with the periods of two low frequency signals. Between charging cycles the capacitor is discharged. When the period of an unknown low frequency signal is to be converted to analog form, one of the charge controlling signals is the unknown signal and the other signal is a known low frequency signal. When the ratio of the periods of two unknown low frequency signals is to be converted to analog form, the two unknown signals control the charging of the capacitor of the ramp generator. The ramp generator charge controlled by the period of the known signal (in the period conversion case) or one of the unknown signals (in the ratio conversion case) is used to control the level of a signal stored by a feedback sample and hold circuit, which circuit controls the output of the current source that charges the capacitor of the ramp generator. The ramp generator charge controlled by the other signal (the unknown in the period conversion case or the other unknown in the ratio conversion case) controls the level of an analog signal stored by an output sample and hold circuit, which signal represents: (a) the period of the unknown signal in the period conversion case; and, (b) the ratio between the periods of the unknown signals in the ratio conversion case.