Tyre pressure monitoring system

The utility model relates to a car safety technical field, in particular to tyre pressure monitoring system, including controller, low frequency trigger and tire pressure sensor, controller output control command tremendously low frequency trigger, low frequency trigger produce low frequency signals and trigger the tire pressure sensor, and the tire pressure sensor is gathered tire pressure information and is exported the controller to, the low frequency trigger including the resistance R, electric capacity C and the inductance L that establish ties in proper order, resistance R's suspension end links to each other with the power through first electronics electronic switch and through second electronics electronic switch ground connection, inductance L's suspension end links to each other with the power through third electronics electronic switch and through fourth electronics electronic switch ground connection, controller output control command control is first, two, three, quadrielectron electronic switch's disconnection or closure to a control method of this system is disclosed. Improve the ability that triggers of low frequency trigger, guarantee to be triggered by the low frequency trigger when tire pressure sensor rotates the optional position along with the tire.