Apparatus for automatically recognizing a frequency of a power supply and method thereof
US5391982A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1993 |
| Grant date | Feb 21, 1995 |
| Priority date | — |
| Expiry date | Feb 22, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for recognizing a frequency of an electric power being applied to an electric/electronic device for preventing an error operation of the electric/electronic device generated when the frequency of power supply to be applied differs from the operating frequency determined at the time of manufacture of the electric/electronic device. The apparatus has a power transformer for transforming commercial alternating current power supply to a driving voltage of the device, a period detecting section for shaping a wave form of output of the power transformer, and simultaneously generating a period detecting signal at every period of that output wave form, and a control section for counting a number of times said period detecting signal is generated during a predetermined time period, whereby the frequency of the applied power supply on basis of the number of times.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.