Self-test circuit for multi-point level indicator
US4476460A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 27, 1981 |
| Grant date | Oct 9, 1984 |
| Priority date | — |
| Expiry date | Mar 27, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/14
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An apparatus is provided for monitoring and indicating the amount of material in a hopper or a bin includes self-test circuitry for automatically testing both a material level sensor and circuitry for storing the output signal generated by the sensor. During the normal operation of the monitoring apparatus, the value of the sensor output signal is compared with the values of predetermined maximum and minimum reference signals. If the sensor output signal is greater than the predetermined maximum value or less than the predetermined minimum value, the test circuit generates a failure indication to the operator of the apparatus. In order to test the sensor output signal storage circuitry, the test circuit disables the sensor and generates a simulated sensor output signal to the storage circuitry. The test circuit then compares the stored signal with the simulated signal and generates a failure indication if they are different.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.