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:
Dec. 15, 1987
Filed:
Apr. 03, 1987
Applicant:
Inventors:
Donald E Zahm, Midland, MI (US);
Gary R Strickler, Midland, MI (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05F / ;
U.S. Cl.
CPC ...
323322 ; 323324 ; 323351 ;
Abstract
An economical astable multivibrator circuit provides a variable frequency, variable duty cycle digital signal for controlling a solid-state relay to provide power proportioning. An optical isolator receives analog input signals and converts those signals into a variable resistance signal for altering the RC time constant of the charge/discharge timing circuit. The controller is capable of driving several solid-state relays simultaneously and includes a powerstat adjustment for manually adjusting the range of power delivered to a load.