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:
Jan. 16, 2018
Filed:
Sep. 30, 2016
Trane International Inc., Davidson, NC (US);
William Randall Erwin, Tyler, TX (US);
Bradley Thomas Wilson, Tyler, TX (US);
Trane International Inc., Davidson, NC (US);
Abstract
An HVAC switching circuit may comprise a current source circuit charging a capacitor used to power an HVAC DC power relay coil. The power relay coil terminal is connected to an activation control circuit which comprises at least one of (1) each of (a) a threshold circuit which activates a first transistor to energize the power relay coil when the voltage across the threshold circuit reaches a first threshold value and (b) a regenerative feedback circuit configured to lower the first threshold value to a second threshold voltage, and (2) a voltage divider connected between a first terminal on the power relay coil and the negative DC supply, and a programmable shunt regulator, configured as a level triggered switch, programmed by the voltage divider and connected between the second power relay coil terminal and the negative DC supply.