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:
Jun. 09, 1992
Filed:
Nov. 30, 1989
David P DeBoer, Elkhart, IN (US);
Johnson Service Company, Milwaukee, WI (US);
Abstract
A control device for energizing and de-energizing temperature changing devices having a primary control unit and a secondary control unit is provided. The primary control unit includes means for sensing an external temperature and generating a signal (Ps) having a value proportional to the external temperature, means for generating a set point signal (Psp), representing one end of a predetermined primary temperature range, and means for generating a differential signal (Pd), representing the difference between signal Psp and the other end of the predetermined primary temperature range are included. Additionally, the primary unit includes a primary switch for connecting power to at least one temperature changing device which is opened and closed in response to combinations of signals Ps, Psp and Pd. The secondary unit includes means for generating an offset signal (So) and means for generating a secondary set point signal (Ssp) having a value proportional to a combination of signal Psp and signal So, and representing one end of a predetermined secondary temperature range. The secondary unit further includes means for generating a secondary differential signal (Sd) representing the difference between signal Ssp and the other end of the predetermined secondary temperature range.