Title:
DIRECT CURRENT CUTOFF SWITCH
Document Type and Number:
WIPO Patent Application WO/2003/105172
Kind Code:
A1
Abstract:
A direct current cutoff switch (1) in which a nonlinear resistor PTC (5) is parallel connected to a contact circuit composed of a fixed contact (4-2) and a movable contact (8-2) electrodes (5-2) via electrodes (5-1). The PTC (5) has a predetermined resistance value at a reference temperature of 25°C. When the switch is closed, no current flows because the voltage between the electrodes (5-1) is almost “0”. When the switch is opened to cut off the current, the contact section is a closed circuit because of the PCT (5), connected parallel between the fixed contact (4-2) and movable contact (8-2), impossibly producing a surge voltage. An arc between the contacts hardly occurs. The PTC (5) is instantly heated due to the passage of the current, drops its resistance value, allows the peak current to flow, and then raises its resistance value, becoming stable at such a high resistance value that a weak current negligible at the rated voltage 42 V flows, thereby substantially cutting off the current.
Inventors:
Takeda, Hideaki c/o UCHIYA THERMOSTAT CO. LTD. (2-176-1, Takas, Misato-shi Saitama, 341-0037, JP)
Application Number:
PCT/JP2003/006412
Publication Date:
December 18, 2003
Filing Date:
May 22, 2003
Export Citation:
Assignee:
UCHIYA THERMOSTAT CO., LTD. (2-176-1, Takasu Misato-shi, Saitama, 341-0037, JP)
Takeda, Hideaki c/o UCHIYA THERMOSTAT CO. LTD. (2-176-1, Takas, Misato-shi Saitama, 341-0037, JP)
Takeda, Hideaki c/o UCHIYA THERMOSTAT CO. LTD. (2-176-1, Takas, Misato-shi Saitama, 341-0037, JP)
International Classes:
H01C7/02; H01H1/50; H01H9/42; H01H9/54; H01H37/52; H01H47/00; H01H33/59; H01H37/54; H01H50/02; (IPC1-7): H01H9/54; H01H37/52; H01H47/00
Attorney, Agent or Firm:
Osuga, Yoshiyuki (3rd Fl, Nibancho Bldg. 8-20, Nibanch, Chiyoda-ku Tokyo, 102-0084, JP)