Rainy days, many owners have this trouble: to frequently adjust the wiper speed, because too slow brush is not clean rain, too fast and affect the line of sight, very affect the driving experience and safety. In order to solve this Sensor pain point, can absorb the rainfall and automatically adjust the speed of the wiper was born, this tall equipment can only be seen in the high-class cars and luxury cars in recent years, this function is popular, many senior or even intermediate The high profile of the car is also common.
The car to play the function of induction rainfall, first of all it has a sensor, that is, the rainfall sensor. The earliest rain sensor is not used in the wiper, it is used in the convertible for the roof and four doors to provide automatic switching function. 90 years, it gradually used on the wiper, around 2006, began to become a standard car. Its working principle is basically the same: there is a light-emitting Pressure Sensor parts responsible for emitting infrared, when the glass surface is dry, the light is almost 100% is reflected back, so that the photodiode can receive a lot of reflected light. When the more rain on the glass, the less the light coming back. So, the wiper is based on this to control the speed of the wipers.
Rain sensor is not a panacea, the sensing range is also a circle, beyond this range, it can do nothing. In other words, if the rain falls on the outside of this circle, this automatic sensor is not working. Therefore, in the design of wiper scraping area, the need to consider the location of the rain sensor. It is generally desirable that the outermost end of the wiper portion of the driver's side wiping blade be kept Speed Sensor at a distance from the rain sensor (that is, the wiper blade on the driver's side can not be scratched to the extent of the rain sensor to avoid misjudgment) The brush area must cover the range of the rain sensor.