Abstract: A pressure detection apparatus has a pressure-sensitive resistor whose first resistance varies according to pressure and a change of its own temperature, a temperature-sensitive resistor which has a same resistance-temperature coefficient as the pressure-sensitive resistor and whose second resistance varies according to the change of the temperature, a current source supplying first and second constant-currents to the pressure-sensitive and temperature-sensitive resistors respectively, and a pressure signal generation output section. The current source adjusts the first and second constant-currents so that when the pressure is an initial pressure, a reference first voltage appearing across the pressure-sensitive resistor and a reference second voltage appearing across the temperature-sensitive resistor become equal to each other.
Type:
Grant
Filed:
September 30, 2009
Date of Patent:
April 2, 2013
Assignee:
NGK Spark Plug Co., LGD
Inventors:
Toshiyuki Matsuoka, Yuzo Higuchi, Yoshinori Tsujimura, Takio Kojima