PURPOSE: To enable the prevention of a feed failure to a transponder at the time of high temperature so as to enable the display of constantly stable performance.
CONSTITUTION: An NTC thermistor 8 with the resistance value lowered in association with temperature rise is provided in series between a feeder coil 6 provided on the vehicle side and used also as an antenna, and a driving circuit for driving this feeder coil 6. In the case of ambient temperature becoming high, the resistance value of the feeder coil 6 itself is increased, but the resistance value of the NTC thermistor 8 is lowered by that part so as to make up for driving power to the feeder coil 6, thereby preventing a feed failure to a key side transponder 18 at the time of high temperature.
| WO/2005/070732 | WAKE-UP CIRCUIT |
| JPS52105435 | NUT WITH LOCKING MEANS |
| JP3515649 | THEFT WARNING DEVICE FOR VEHICLE |
MIZUNO HIROMITSU
KUMAGAI KATSUHIDE
OTAKI KIYOKAZU
