The role of air conditioning sensors, the use of sensors is very common in our lives, there are relatively many types of sensors, and the scope of application is relatively light. Different sensors have different functions. Let's learn about the role of air conditioning sensors.
Function of air conditioning sensor 1 Air conditioning sensor is also called temperature sensor. Its main function in air conditioning is to detect the temperature of each part of air conditioning. There are many air conditioning sensors in the air conditioner, which are distributed in all important parts of the air conditioner.
The basic number of air conditioning sensors is three. In large or high-end air conditioners, the number of air conditioning sensors will multiply. Let me introduce the working principle, function and price of air conditioning sensor to you.
Working principle of air conditioning sensor
Air conditioning temperature sensor is a thermistor with negative temperature coefficient, which is called NTC for short. Its resistance decreases with the increase of temperature and increases with the decrease of temperature. The resistance at 25℃ is a nominal value.
Air-conditioning temperature sensors are all connected in series with a resistor to divide the voltage by 5V (+3.3V for some air conditioners), which is divided and sent to CPU. Because the temperature sensors of air conditioners all use negative temperature coefficient, that is, the resistance decreases when the temperature rises and increases when the temperature drops.
So the input voltage law of CPU is; When the temperature increases, the input voltage of CPU increases, and when the temperature decreases, the input voltage of CPU decreases. This changed voltage enters the CPU for internal analysis and processing to judge the current pipe temperature or room temperature, and the operating state of the air conditioner is controlled through internal programs and artificial settings.
Because the sampling voltage sent to CPU will change in a wide range with the change of temperature, manufacturers usually design the sampling voltage to be half of the power supply voltage based on 25 degrees in order to leave enough space for the voltage change caused by temperature change. If the sampling voltage is designed to be too high or too low, it can't normally reflect the current temperature change.
Since the resistance of R 1, R2 and R3 series resistors is constant, if the internal resistance of the CPU interface is not considered (in fact, the internal resistance of the interface is relatively large and can be ignored), then the voltages of the three CPU input points A, B and C should be around 2.5V (at 25 degrees), and the three sensors RT 1, RT2 and RT3 can only be used in the daytime.
Function of air conditioning sensor
1. Indoor ambient temperature sensor: mainly detects the indoor ambient temperature and controls the start and stop of the air conditioner.
2. Internal coil sensor: mainly detects the temperature of the internal machine tube, prevents cold air in winter and defrosts the external machine. (Some are external machine tube defrosting cream)
In summer, the internal machines are protected from freezing.
There are usually three basic probes:
One is the temperature control probe, which is located in the filter screen of the air inlet of the indoor unit of the air conditioner (the cabinet is outside the fan and hung on the evaporator);
One is the probe for discharging cold air when the air conditioner is heating, which is on the evaporator of the indoor unit;
One is an automatic defrosting probe for air conditioning heating, which is on the condenser of the outdoor unit.
Open the panel of the indoor unit, take out the filter screen, and see a small black head on the evaporator of the indoor unit. The sensor is the temperature sensor of the indoor unit.
If the electric appliance box cover is opened, the temperature sensor is connected with the temperature sensor and inserted into the evaporator tube of the internal machine, which is the tube temperature sensor. Different styles have different positions.
Hang up: room temperature sensor, open the internal unit panel, and take off the filter to see it.
The tube temperature sensor connected in parallel with the room temperature sensor needs to open the inner cover of the machine, remove the electrical box and plug it into the evaporator.
Cabinet machine: room temperature sensor, open the lower panel, next to the wind wheel.
Tube temperature sensor needs to completely open the internal machine and insert the evaporator.
Price of air conditioning sensor
The price of air conditioning sensor is 0.0 1 yuan to 220 yuan. (Price source network, for reference only. )
What is the price and working principle of air-conditioning sensors on the market? What is the main function of air-conditioning sensors? I have given you a detailed introduction above. After reading the above, you should also know the basic information of air conditioning sensors.
Using air conditioning sensors can well sense the temperature of various components of air conditioning, so as to better control the environment and give people a comfortable indoor environment.
The function of air conditioning sensor 2 1. Where is the temperature sensor of Gree air conditioner?
Normally in the form of blowing air, next to the heating pipe!
In addition, there are at least two outdoor temperature sensors at the outlet of the outdoor coil and fan of the inverter air conditioner:
One on the outdoor coil is used to detect the supercooling of refrigerant.
The other one is located at the outlet of the fan, and its purpose is to monitor the outlet temperature and provide basis for the change of the speed of the fan motor.
2. What does Gree air-conditioning temperature sensor tc 15k stand for?
For low-voltage protection, check whether the ammonia pressure is enough first, and then check the pressure switch.
And test whether the low pressure switch works. If so, you can pull out the wire and test whether there is 220V electricity in the meter. If not, look at the line. If there is no problem, change the board.
The temperature sensor is broken, and the air conditioning temperature sensor is a thermistor. TC5K indicates that the resistance at 25 degrees is 5 kiloohms.
Three, air conditioning temperature sensor working principle:
1. Pressure-type temperature sensor: The basic principle of pressure-type temperature sensor is to measure temperature by using the property that the pressure of temperature-sensitive substances changes with temperature.
2. The expansion temperature sensor is made according to the principle that objects expand when heated and contract when cooled. According to the form of swelling substance, it can be divided into solid expansion type and liquid expansion type mercury thermometer.
It uses mercury liquid to measure temperature by thermal expansion and cold contraction, and belongs to liquid expansion thermometer and bimetal thermometer. The temperature measuring element of bimetallic thermometer is made of two different metal materials with different linear expansion coefficients by overlapping welding. Because the linear expansion coefficients of the two pieces of metal are different-when the temperature rises, the bimetal will bend to the side with small expansion coefficient, and the higher the temperature rises, the greater the bending.
It uses the relationship between the deformation and displacement of bimetal and the temperature change, and drives the pointer to indicate the temperature value through the lever amplification mechanism. At the same time, the recording pointer (pen) is driven by the lever to automatically record the measured temperature on the recording paper moving at a constant speed. Bimetallic temperature juice has simple structure, high mechanical strength and low price, but its precision is low, and its measuring range and application range are limited.
3. Thermal resistance temperature sensor: Thermal resistance temperature sensor can be divided into metal thermal resistance and semiconductor thermistor. The resistance of most metal thermal resistors increases with the increase of their temperature, which is called positive temperature coefficient;
However, the resistance of semiconductor thermistor generally decreases with the increase of temperature, that is to say, it has a negative temperature coefficient. Because the resistance of conductor and semiconductor varies with temperature, the corresponding temperature can be measured by measuring their resistance.
Copper thermal resistance is characterized by linear relationship between resistance value and temperature, relatively large temperature coefficient of resistance, easy purification of materials and relatively cheap price: but its resistivity is low, its accuracy is not high, it is easy to oxidize at high temperature and its chemical stability is poor; Therefore, under the condition that the temperature is not high and there is no special restriction on the sensor volume, copper thermal resistance can be used.
Semiconductor thermistors are widely used as temperature sensors. There are two kinds of semiconductor thermistors: NTC (negative temperature coefficient) and PTC (positive temperature coefficient). Conductor thermistors come in many shapes. Semiconductor thermistors are usually made of oxides of metals such as iron, nickel, molybdenum, titanium, magnesium and copper. When used in the field, the distance between the controller and the thermistor can reach 800 meters, so it is especially suitable for temperature telemetry and remote control in the automatic control system of air conditioning. Quality measurement of temperature sensor:
As for Gree air-conditioning temperature sensor, it plays an important role in Gree air-conditioning products. It has several categories and is suitable for different scenes. The principles they use include professional knowledge in many fields, such as the principle that objects expand when heated and contract when cooled, which is the source of the principles used by the expansion temperature sensor. In addition, in view of the possible doubts of users, I also introduced the specific location of Gree air-conditioning temperature sensor for everyone to make judgments in the actual operation process.
Function of air conditioning sensor 3. Detection method of sensor
There are three detection methods of sensors: direct detection, indirect detection and combined detection. Direct detection Direct detection means that when a sensing instrument is used for detection, the reading of the instrument can directly indicate the required result without any operation. For example, using a magnetoelectric ammeter to detect the current of the circuit and using a spring tube pressure gauge to detect the pressure of the boiler are all direct detection.
The advantage of direct detection is that the detection process is simple and fast, but the disadvantage is that the detection accuracy is not easy to reach very high. This detection method is widely used in engineering.
Indirect detection in some detection occasions, it is impossible or inconvenient to directly detect the detected object, so it is difficult to insist on detecting several quantities that have a certain functional relationship with the measured physical quantity first, and then substituting the detected values into the cluster number relationship, and obtaining the required results through calculation. This method is called indirect detection. Indirect detection requires more detection than direct detection, the calculation process is more complicated, and there are many factors leading to crop failure.
However, if the error is analyzed and the optimized detection method is selected and determined, indirect detection can be carried out under ideal conditions. The accuracy of detection results is not necessarily low, and sometimes higher detection accuracy can be obtained-indirect detection is generally used in situations where direct detection is inconvenient or indirect detection means are lacking.
When the sensor instrument is used for joint detection, if the measured physical quantity must be solved by simultaneous equations, the final result can be obtained. This kind of detection is called joint detection. In the process of joint detection, it is generally necessary to change the test conditions to obtain the data needed for a set of simultaneous equations.
Joint detection is a special precision detection method, which has complex operation procedures and takes a long time, and is generally suitable for scientific experiments or special occasions. The quick sealing joint is the sealed quick joint of Haiyipu Machinery, which can make the test connection easier, faster and safer.