Abnormality detection device of speedometer circuit

摘要

The present invention relates to an abnormality detection device of a speedometer circuit. When the vehicle speed sensor 10 detects and signals a speed of a vehicle currently being driven by a digital signal, the pulse count operation unit 20 calculates the signaled pulse. Detects the speed of the car currently running and signals it to the VFD driving circuit 40. At the same time, the pulse comparator 60 compares the signal detected by the vehicle speed sensor 10 with the normal signal to compare the speedometer 30 with the VFD. The signal is displayed on the speed meter 30 when the value of the VFD driving circuit 40 which controls the display unit 50 to operate is compared with the pulse comparison circuit 60, and the VFD is not the same. By blinking the VFD element of the display unit 50, the driver is notified of the abnormality of the speedometer-related circuit, so that the driver can detect abnormality or malfunction of the speedometer-related system caused by disconnection and short circuit of the speedometer-related circuit. It is possible to contribute to securing the safety of cars and improving the merchandise.