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. 23, 2002
Filed:
Dec. 12, 1997
Other;
Abstract
When a MOS transistor is turned off, a forward current flows into a diode connected to the MOS transistor. When the MOS transistor is conducted, a reverse bias is applied to the diode. When the MOS transistor is turned on during the reverse recovery time of the diode, a short-circuit current flows into the MOS transistor, the diode, and a battery connected in series with the diode and the MOS transistor. In this case, an overcurrent flows through the wiring of the battery momentarily, and electromagnetic wave generates from the wiring. Accordingly, noise caused by the electromagnetic wave is generated in an antenna to a radio receiver. The drain current of the MOS transistor is gradually increased by a delay circuit, and the MOS transistor is shifted from a completely turned-off state to a completely turned-on state with a time period longer than a reverse recovery time of the diode. Consequently, no reverse current flows through the diode. Therefore, a short-circuit current is prevented from flowing through the battery, the diode, and the transistor, and no noise is generated in the receiver.