TIRE INTERNAL PRESSURE ALARM DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce malfunction of a tire internal pressure alarm device by eliminating influence of noise on a tire internal pressure signal detected by a pressure detection means. SOLUTION: Tire internal pressure detected by a pressure sensor 11 is converted into a quantization signal of 500 nsec of a pulse width of 1-bit and a sampling frequency 34 kHz by a first CPU 1 and the quantization signal is transmitted to a control circuit board B side by serial communication. In a second CPU 2, correctness of the transmitted quantization signal is decided based on quantization conditions of the pulse width and the sampling frequency and transmission speed. Only a pulse string decided as a right one is transmitted to a voltage calculation means 4 to obtain a voltage signal proportional to tire internal pressure.