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:
Oct. 06, 1987
Filed:
Aug. 28, 1986
Patrick S Roberts, Rolling Meadows, IL (US);
Leonard Weiss, Grayslake, IL (US);
Spartus Corporation, Skokie, IL (US);
Abstract
A transformerless power supply and display energizing circuit for a clock circuit with a duplex optoelectronic display driven by a low voltage integrated clock circuit having positive and negative voltage input terminals and the duplex display having a first terminal connected to a first common cathode and a second terminal connected to a second common cathode of the display for energizing it. The transformerless circuit is powered from an AC source. An impedance, which may be either resistive or reactive, reducing the AC voltage to a level suitable for the integrated clock circuit. The transformerless circuit generates synchronous DC level-shifted pulse trains for driving the positive input terminal of the integrated clock circuit alternately between a first voltage and a reference voltage while synchronously driving the display first terminal between said first voltage and a voltage of equal amplitude and opposite polarity. The display second terminal is held at the reference voltage.