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:
Apr. 21, 1981
Filed:
Feb. 05, 1979
Jack L Wilhelmson, Cheraw, SC (US);
Lab-Line Instruments Inc., Melrose Park, IL (US);
Abstract
The apparatus may be used to control heater elements for an over chamber. The heater elements are operated in accordance with the output of a comparator having on one input a voltage representative of the temperature in a chamber. The voltage on the other input is established in accordance with the desired or ultimate temperature in the chamber. As long as the volage on the second-mentioned input is greater than the voltage on the other input, the heater elements will be energized to heat the chamber. The voltage on the second-mentioned input is modulated with a triangular wave so that the heater elements are operated intermittently as the desired temperature of the chamber is approached. The amplitude of the triangular wave varies with the desired temperature so that at higher and higher oven temperatures, the heater elements start to become intermittent at higher and higher temperatures.