Title:
TEMPERATURE MEASURING APPARATUS
Document Type and Number:
Japanese Patent JP3128973
Kind Code:
B2
Abstract:
PURPOSE: To measure an abruptly varying temperature positively and to prolong the service life of relay by normally switching relays at temperature measuring points with long period whereas switching the relays with short period when the temperature to be measured exceeds a dangerous temperature.
CONSTITUTION: When a switching signal is delivered from a CPU 52 to an output port 54, relays RYn are energized through a relay drive circuit 6 and transistors Trn to close contacts ryn thereof. A temperature signal Tn from a thermister Trn is subjected to A/D conversion 51 through contacts ryn and an isolation amplifier 4 and the CPU 52 measures a temperature which is then compared with a dangerous temperature value Tn' stored in a memory 53. If Tn≥Tn' is not satisfied, a sampling time Δt1 is set and the relays RYn are switched sequentially at a time interval of Δt1 through the circuit 6 thus measuring the temperature in the order of forward converting section, DC reactor section, reverse converting section, and forward converting section. If Tn≥Tn' is satisfied, a sampling time Δt2 shorter than Δt1 is set and then the temperatures are measured similarly.
Inventors:
Noboru Takada
Application Number:
JP21950892A
Publication Date:
January 29, 2001
Filing Date:
August 19, 1992
Export Citation:
Assignee:
KABUSHIKI KAISHA MEIDENSHA
International Classes:
G01K7/00; G01K7/02; G01K7/16; H02H5/04; (IPC1-7): G01K7/00; G01K7/02; G01K7/16; H02H5/04
Domestic Patent References:
| JP6394520A |
Attorney, Agent or Firm:
Fujiya Shiga (1 person outside)