With the development of science and technology, Voice Prompts Devices sensor technology is developing and infiltrating into people's daily lives. The induction doorbell is converted into an electrical signal by means of information of objects present in various sensors, and the electrical signal is used to control playback. Object or music. According to the sensing method, the doorbell/welcome is as follows:
1. Human body / infrared induction;
2. Light sensing;
3. Ultrasonic induction;
4. Microwave induction;
5. Door magnetic induction.
The most widely used on the market today are light sensors and human/infrared sensors. The light sensor doorbell is cheaper than others. However, the light sensor will affect the sensing range and sensitivity through changes in the environment, and the farther the sensing range is, the more sensitive the sensitivity is. The high and negative sensing ranges become smaller and the sensitivity becomes very poor. Therefore, the user may feel that the light-sensing doorbell is unstable, and it is difficult to determine the most suitable position for the position.
Relatively speaking, the human body infrared sensor doorbell does not have such a problem, because the human body infrared sensor can only respond to changes in infrared light, it is only sensitive to the motion of the object, and is not affected by the change of the light. . When the sensor detects that someone is passing, it controls the voice device to turn on, welcomes the object/music playback, and automatically turns off when people leave, without wasting power.
However, infrared sensing also has a disadvantage that it is affected by the ambient temperature. When the ambient temperature exceeds 40 ° C, the sensitivity is greatly reduced and the sensing distance is greatly reduced.
If you need to install outdoors (in a hot environment) or need to sense something that you can't heat yourself, the new ultrasonic-sensing doorbell and microwave-sensing doorbell are the best choice. These two methods are not affected by the outside temperature. This effect also senses static or non-heated objects, providing a more comprehensive preventive reminder. However, the cost of ultrasonic induction and microwave induction will be relatively expensive, so the mainstream is still the human body infrared sensor doorbell, which is cost-effective.
Users should choose different types of welcome devices according to different use occasions. For example: welcome to the store door, use human body induction, counter/checkout/shelf, you can use light sense, if you want to use outdoor, choose ultrasonic induction. Or microwave induction.