58results about How to "High resistance precision" patented technology

The invention discloses a breaker simulating device used for replacing a real high-voltage breaker in the protecting testing process. The breaker simulating device comprises a breaker circuit which comprises a plurality of breaker circuit bodies identical in circuit structure and a plurality of extension relay circuits identical in circuit structure. A breaker protecting switching-on switch is connected into a closing coil and a controller switching-on opening loop. The closing coil and the controller switching-on opening loop are connected in parallel. A breaker protecting trip switch is connected into a tripping coil and a controller tripping opening loop. The tripping coil and the controller tripping opening loop are connected in parallel. One relay is adopted in each extension relay circuit to serve as contact extension, and each extension relay circuit is used for simulating an auxiliary switch contact of the breaker to be opened at the switching-on and switching-off position. The switching-on and switching-off time of the sixth simulated breaker can be set according to needs, and the precision of the switching-on and switching-off time of the simulated breaker is high.

The invention provides a thermistor chip and a preparation method of the thermistor chip. The thermistor chip is prepared from the following raw materials in percentage by mass: 40 to 60 percent of manganese nitrate, 20 to 35 percent of cobalt nitrate, 10 to 20 percent of nickel nitrate and 5 to 10 parts of aluminum nitrate, wherein the raw materials are all chemical pure crystals. The preparation method comprises the following steps of dissolving the crystals into deionized water to prepare a mixed solution; carrying out thermal decomposition on the mixed solution to obtain mixed powder; mixing the mixed powder with a solvent, a binding agent, a dispersing agent and a plasticizing agent to prepare slurry; carrying out wet film casting on the slurry to obtain a block; carrying out the technologies of drying, cutting, adhesive discharging, sintering, polishing-grinding, silver coating and scribing on the block, thus obtaining the thermistor chip. The electrical resistivity of the thermistor chip provided by the invention is 20 Kohm.mm to 30 Kohm.mm, and a material B value is 4100 K to 4700 K; the preparation method of the thermistor chip is simple, a process of settling and standing or gelating is not needed, and the thermistor chip has the characteristics of high sensitivity, less energy consumption and short production period.