Circuit principle of car road code table for detecting vehicle speed
As shown in the figure, the circuit is composed of a 555 time base circuit. The detection principle is that the vehicle speed is proportional to the number of ignitions of the ignition line. When the ignition coil is turned on or off, a pulse signal is generated, which is connected as shown in the figure, and can form a road code table. Original Bulb Lamp With Housing The original projector bulb lamp with housing is installed with the original brand factory projection lamp, providing bright and clear pictures, visual appreciation, high quality and worry-free service. It can be directly put into the projector, the installation is simple, and no reassembly is required. Original Bulb Lamp With Housing,Buy Projector Lamp,Projector Lamp Light,Original Projector Shenzhen Happybate Trading Co.,LTD , https://www.happybateprojector.com
555 and R3, C2, etc. constitute a monostable timing circuit. The negative pulse 555 timing circuit generated by the on and off of the ignition coil is set, and the third leg generates a pulse having a width of Ï„=1.1R2C2. The speed of the output pulse varies with the speed of the vehicle, and the meter indicates its average value. 