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:
Nov. 16, 1976
Filed:
Jan. 29, 1975
Hitoo Iwasa, Takatsuki, JA;
Gota Kano, Nagaoka, JA;
Matsushita Electric Industrial Co., Ltd., Kadoma, JA;
Abstract
Across a D.C. power source 1, a load 2, a switching element 4, such as a transistor having a control electrode c (base), and a voltage detection means 5, such as a resistor, are connected in series, and a known negative resistance device 6, having two terminals 31 and 32, is connected by its one terminal 32 to said control electrode c of the switching element 4 and by its other terminal 31 to one end of said series resistor 5 which one end is opposite to that connected to said switching element (4), wherein said negative resistance device 6 comprises, as shown in FIG 2, known complementary connection of a depletion mode n-channel field-effect transistor (FET) and a depletion mode p-channel FET. The FETs are connected from source to source, and from the gate of each to the drain of the other so that when an overcurrent to the load 2 or an overvoltage at the voltage source 1 occurs, voltage across said resistor 5 exceeds a preset value, the negative resistance device 6 is cut-off, thereby cutting off the switching element 4.