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:
Jul. 26, 1977
Filed:
Jun. 15, 1976
Edward Tarchalski, Lawrenceville, NJ (US);
John C Wilkinson, Hightstown, NJ (US);
Heinemann Electric Company, Trenton, NJ (US);
Abstract
This invention comprises a fusible resistor in a solid state relay comprising two solid state switches connected in parallel with each other, but in series with a load and a source of current. When the first of the two switches is switched on, the second switch also switches on, and conducts, supplying sufficient current to the load, thus reducing the voltage across both switches to that of the voltage drop across the second switch. Should the second switch fail to become turned on when the first switch is turned on, there will be a higher voltage across the first switch (and the components in series with it, if any) causing excessive current to flow through the first switch, resulting in its overheating and possibly fire, particularly if the switch is encapsulated. By providing a fusible resistor in the circuit of the first switch, the fusible resistor will open at such time and disconnect the first switch from the circuit, preventing a possible fire or possible damage to adjacent equipment.