Mobile phone sensor, as its name implies, is the sensor used in mobile phones. Belonging to a sensor. The definition and principle of sensor are introduced below. Definition of sensor A sensor is a device that can convert physical or chemical quantities into easy-to-use electrical signals. The definition of IEC (International Electrotechnical Commission) is: "The sensor is the pre-element in the measurement system, which converts the input variables into measurable signals". According to Gopel et al, "a sensor is a sensitive element including a carrier and a circuit connection", while "a sensor system is a system with some information processing (analog or digital) capability". The sensor is an integral part of the sensing system and the first gateway for the input of the measured signal. Sensors convert one form of energy into another. There are two kinds: active and passive. Active sensors can directly convert one form of energy into another without external energy or excitation source. Passive sensors cannot directly convert the energy form, but can control the energy input from another input or excitation energy. Sensors undertake the task of converting specific characteristics of an object or process into quantities. Its "object" can be solid, liquid or gas, and their state can be static or dynamic (that is, process). After transformation and quantization, object features can be detected in many ways. The characteristics of an object can be physical or chemical. According to its working principle, it converts the characteristics or state parameters of an object into measurable electric quantities, and then separates the electric signals and sends them to the sensor system for evaluation or marking. The principle and structure of the sensor are as follows: a special torsion strain gauge is attached to a special elastic shaft to form a variable bridge, which is the basic torque sensor; The shaft is fixed with (1) secondary coil of energy toroidal transformer, (2) primary coil of signal toroidal transformer, and (3) printed circuit board on the shaft, which includes rectifying and stabilizing power supply, instrument amplifier circuit, V/F conversion circuit and signal output circuit. (1) excitation circuit, (2) primary coil (input) of energy toroidal transformer, (3) secondary coil (output) of signal toroidal transformer are fixed on the sensor housing, and (4) signal processing circuit provides +/- 15V power supply to the sensor during its working process. The crystal oscillator in the excitation circuit generates a square wave of 400Hz, which passes through TDA2030. The energy loop transformer T 1 is used to transfer from the static primary winding to the rotating secondary winding, and the obtained AC power supply is obtained by the coaxial rectification filter circuit, which is used as the working power supply of the operational amplifier AD822. A high-precision regulated power supply consisting of a reference power supply AD589 and a dual-channel operational amplifier AD822 generates a precision DC power supply of 4.5V, which is used as both a bridge power supply and a working power supply for amplifiers and V/F converters. When the elastic shaft is twisted, the mV-level strain signal detected by the strain bridge is amplified into a strong signal of 1.5V 1V by the instrument amplifier AD620, and then converted into a frequency signal by the V/F converter LM 13 1, and transmitted from the rotating primary coil to the stationary secondary coil through the signal ring transformer T2. After filtering and shaping by the signal processing circuit on the shell, the frequency signal proportional to the torque on the elastic bearing can be obtained. The signal is TTL level, which can be provided to a special secondary meter or frequency meter for display or directly sent to a computer for processing. Because the gap between the dynamic and static rings of the resolver is only a few tenths of a millimeter, and the upper part of the sensor shaft is sealed in the metal shell, it forms an effective shielding and has strong anti-interference ability. Classification of sensors Inclination sensors Inclination sensors are widely used in military, aerospace, industrial automation, construction machinery, railway locomotives, consumer electronics, marine ships and other fields. Huige Company provides domestic users with the most comprehensive and professional product solutions and services in the world. Provide tilt sensors based on more than 500 specifications such as servo type, electrolyte type, capacitance type, inductance type and optical fiber type. Acceleration sensors (linear acceleration and angular acceleration) are divided into low-frequency high-precision force balance servo type, low-frequency low-cost thermal convection type and medium-high frequency capacitive acceleration displacement sensor. The total frequency response range is from DC to 3000 Hz. The application fields include automobile motion control, automobile inspection, household appliances, game products, office automation, GPS, PDA, mobile phone, vibration detection, building instruments and experimental equipment. Infrared temperature sensors are widely used in household appliances (microwave ovens, air conditioners, range hoods, hair dryers, toasters, induction cookers, woks, heaters, etc. ), medical/household thermometers, office automation, portable non-contact infrared temperature sensors, industrial field temperature measuring instruments and electric power automation. We can not only provide sensors, modules or complete temperature measuring instruments, but also provide a package of solutions including optical lenses, ASIC and algorithms according to users' needs. For more information, please visit the sensor application field of Huige Science and Technology Network, involving mechanical manufacturing, industrial process control, automotive electronic products, communication electronic products, consumer electronic products and special equipment. (1) Special equipment Special equipment mainly includes professional electronic equipment used in medical treatment, environmental protection, meteorology and other fields. At present, the medical field is an emerging market, with huge sales of sensors and considerable profits, which requires sensor devices to develop in the direction of miniaturization, low cost and high reliability. (2) Sensors used in industrial automation, such as process control, industrial machinery and traditional sensors; Various measurement process variables (such as temperature, liquid level, pressure, flow rate, etc.). ); Traditional proximity/positioning sensors for measuring electronic characteristics (current, voltage, etc.). ) and physical quantities (motion, speed, load, intensity) have developed rapidly. (3) The rapid growth of mobile phone production of communication electronic products and the continuous increase of new functions of mobile phones have brought opportunities and challenges to the sensor market. The market share of color screen mobile phones and camera phones is increasing, which increases the application proportion of sensors in this field. In addition, ultrasonic sensors for group phones and cordless phones, magnetic field sensors for magnetic storage media, etc. Will show strong growth. ⑤ The key to the level of electronic control system of modern luxury cars in automobile industry lies in the number and level of pressure sensors. At present, there are dozens to hundreds of sensors installed in an ordinary family car, while there are more than 200 sensors in luxury cars, including more than 30 kinds and 100 kinds.