Safety switch with imbalance test
US10072997B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 2017 |
| Grant date | Sep 11, 2018 |
| Priority date | — |
| Expiry date | May 11, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/9651
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus for an imbalance test includes a strain measurement module that measures a strain voltage across terminals of a strain gauge. The strain voltage is representative of an amount of force on the strain gauge. The apparatus includes a test measurement module that measures a test voltage across the terminals of the strain gauge while a test resistor is connected in parallel with a resistor of the strain gauge. The test resistor is connected while the test measurement module measures the test voltage and is disconnected while the strain module measures strain voltage. The apparatus includes an average module that calculates an average strain voltage from two strain voltage measurements. The strain voltages are measured preceding and after the test voltage measurement. The apparatus includes a difference module that determines a difference voltage. The difference voltage is a difference between the average strain voltage and the test voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.