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:
May. 14, 2002
Filed:
Feb. 25, 1998
International Business Machines Corporation, Armonk, NY (US);
Abstract
A leak current is prevented from flowing during a power off state in a power supply unit having a remote power on/off function by using the momentary switch. In a state of power off, i.e. a state in which a switch SW is turned off, power is not applied to a latch circuit and hence power is not consumed. A switch drive circuit does not consume power. When a user depresses a momentary switch SW during a state that the switch SW is turned off, the switch drive circuit turns the switch SW on. As a result, the latch circuit can receive a drive voltage V from a node located down stream of the switch SW so that it can store or latch the turn on state of the momentary switch SW After that, when the user releases the momentary switch SW it returns to an original position and operation of the switch drive circuit which turns the switch SW on is terminated. However, at this point of time, it becomes possible to maintain the turn on state of the switch SW by the operation of the latch circuit