Electrothermal wire responsive miniature precision current sensor
US4538199A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 14, 1983 |
| Grant date | Aug 27, 1985 |
| Priority date | — |
| Expiry date | Jul 14, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H5/044
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A resistance wire sensing overcurrent protection module (CSM) for an electrical supply circuit (SC) having a hot temperature sensing diode (32) mounted at the center portion (8c) of an M-shaped resistance wire (8) connected in the supply circuit and an ambient temperature sensing diode (20) mounted on a substrate (18) supported between the supply terminals (4a-b, 6a-b), both diodes being connected to respective pairs of terminals (12a-b, 10a-b) mounted on a header (18) along with the supply terminals. A cover (46) is mounted on the header and filled with glass micro-balloons (48) to isolate thermally the two diodes. A constant current circuit (49) supplies constant current to the two diodes which operate a differential amplifier (52) having an output proportional to the temperature difference as a measure of supply current. This output trips a Schmitt trigger comparator (54) when the supply current rises to an overload value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.