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, 1994
Filed:
Oct. 11, 1991
Dennis M Pryor, Swindon, GB;
Ian P Atkins, Swindon, GB;
Michael Challis, Swindon, GB;
David M Williams, Faringdon, GB;
Raychem Limited, , GB;
Abstract
A number of arrangements for protecting an electrical circuit from an electrical overcurrent are disclosed. In the arrangements the base or gate of a switching transistor (4, 101, 161, 222, 401) is held in a voltage divider, one arm of which comprises a control transistor (6, 102, 162, 222, 404) whose base or gate is itself held in a voltage divider. When an overcurrent is experienced the control transistor switches on causing the switching transistor to turn off. The arrangement may include a shunt switching circuit to shunt the overcurrent across the load. It may include a resetting circuit that will attempt to reset the switching circuit after the overcurrent has been experienced. In one embodiment the arrangement includes means such as a battery, dc--dc voltage converter or Seebeck device in order to reduce or eliminate any initial voltage drop across the switching circuit.