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. 26, 1999
Filed:
Sep. 11, 1997
John R Reader, Jr, Newark, DE (US);
TA Instruments, Inc., New Castle, DE (US);
Abstract
A heater controller for allocating heaters to cool a thermal chamber of a scientific instrument evaporates cryogenic liquid to produce a coolant gas. The gas is injected into a chamber to cool a sample disposal therein. The controller allocates low-capacity heaters in compliance with IEC guidelines to prevent problems generally associated with switching of large current loads, such as heaters. In one embodiment, heaters are activated so as to avoid jump discontinuities by effectively averaging the power delivered by the heaters. A second embodiment reduces complexity by essentially disregarding the problem of the jump discontinuity. A third embodiment groups the heaters according to a binary grouping scheme. The heater controller of the present invention can be used to control temperature according to a user supplied temperature profile.