Patent ID: 7343263

Claim:
An electronic timer, comprising: a parallel unit comprised of a plurality of aging devices connected in parallel and having an input terminal and an output terminal, each of the aging devices being configured to be turned from on to off, or, from off to on without a power supply for a predetermined time defined with amounts of stored electric charge and formed of a transistor which includes a floating gate storing the electric charge; a current detecting unit configured to detect a sum current of currents flowing in the aging devices of the parallel unit; and a time measuring unit configured to measure a time from immediately after an interruption of power supplying to a resumption of power supplying from the sum current, wherein the time measuring unit stores a first sum current detected immediately before the interruption of power supplying and a second sum current detected at the resumption of power supplying, and measures the time from immediately after the interruption of power supplying to the resumption of power supplying, on the basis of the stored first sum current and the stored second sum current and an elapse-time change characteristic in an intermediate transition state in which the parallel unit changes from an on-state to an off-state or vice versa, and which represents a relation between the sum current and a time elapsed after a charge is stored in each of the aging devices.