Security device prohibiting the function of an electronic data processing unit after a first cutoff of its electrical power
US4795893A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 10, 1987 |
| Grant date | Jan 3, 1989 |
| Priority date | — |
| Expiry date | Jul 10, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07F7/1083
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The invention relates to a security device (1) prohibiting the execution of at least one function of an electronic data processing unit (2) after a first cutoff of its electric power even in the case of a resumption of supply voltage. This device includes a first means (8) that functions only once in the course of a period beginning at the instant (T.sub.0) of a first connection to voltage by the power supply (3), and finishing prior to the instant (T.sub.2) of a first cutoff of this power supply, and a second means (10) connected to the output of the first means (8) and furnishing an inhibiting signal having a first level that authorizes the function of the unit, from the instant (T.sub.0) of the first connection to voltage until the instant (T.sub.2) of the first cutoff, this inhibiting signal having a second level that prohibits said execution of said function beginning at the instant (T.sub.2) of the first cutoff, this inhibiting signal maintainin this second level even in the case of a resumption of voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.