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. 07, 1988
Filed:
Nov. 25, 1986
Katsuharu Matsuo, Aichi, JP;
Teruya Tanaka, Yokkaichi, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
An electromagnetic induction cooking apparatus having a heating coil, an inverter for supplying an input power to the coil, and a load-identifying circuit. The coil comprises two coils elements. The first coil elements has a first number (N.sub.1) of turns, and the second coil element has a second number (N.sub.2) of turns. The load-identifying circuit identifies the material of a load (e.g., a pan) and selects the first coil element or the second coil element in accordance with the material of the load. When the circuit selects the first coil element, a first DC voltage is applied to the inverter, and the inverter generates and supplies a first high-frequency current of frequency f.sub.1 to the first coil element. When the circuit selects the second coil element, a second DC voltage is applied to the inverter, and the inverter generates and supplies a second high-frequency current of frequency f.sub.2 to the second coil element. The ratio of N.sub.2 to N.sub.1 (N.sub.2 /N.sub.1) is about four to six times the product of the ratio of E.sub.2 to E.sub.1 (E.sub.2 /E.sub.1 ) and the (-1/4)th power of the ratio of f.sub.2 to f.sub.1 (f.sub.2 /f.sub.1).