What is the working principle and role of air conditioning sensors?

Air conditioner sensors are also called temperature sensors. The main function of air conditioners is to detect the temperature of various parts of the air conditioner. There are more than one air conditioner sensors in the air conditioner, and they are distributed in various important parts of the air conditioner. The most basic number of air conditioner sensors is three. In large or high-end air conditioners, the number of air conditioner sensors will increase exponentially. The following editor will introduce the working principle of the air conditioner sensor, the role of the air conditioner sensor, and the price of the air conditioner sensor.

Working principle of air conditioning sensor

The air conditioner temperature sensor is a thermistor with a negative temperature coefficient, referred to as NTC. Its resistance decreases with increasing temperature and increases with decreasing temperature. The resistance at 25°C is the nominal value.

After the temperature sensor of the air conditioner is connected in series with a resistor, the voltage of 5V (+3.3V used by some air conditioners) is divided, and the divided voltage is sent to the inside of the CPU. Because the air conditioner temperature sensor uses a negative temperature coefficient thermistor, that is, its resistance decreases when the temperature increases, and its resistance increases when the temperature decreases. Therefore, the input voltage law of the CPU is: when the temperature increases, the input voltage of the CPU increases, and when the temperature decreases, the input voltage of the CPU decreases accordingly. This changed voltage enters the internal analysis processing of the CPU to determine the current tube temperature or room temperature, and controls the operating state of the air conditioner through internal procedures and artificial settings.

Since the sampling voltage sent to the CPU will vary in a large range with the change of temperature, manufacturers usually design the sampling voltage to be half of the power supply voltage at 25 degrees, so as to give rise to temperature changes. The voltage change allows sufficient room. If the sampling voltage is designed too high or too low, it will not reflect the current temperature change normally. Since the resistance of each series resistance of R1, R2, and R3 is constant, if the resistance of the internal resistance circuit of the CPU interface is not considered (in fact, the internal resistance of the interface is relatively large, you can not consider it), then you must ensure that A, The input voltage of the three CPUs of B and C is about 2.5V (at 25 degrees). The three sensors RT1, RT2 and RT3 can only be used in the daytime and the sensors with the same resistance value of the three series resistances (R1, R2 and R3). Otherwise, the voltage drop at this point deviates more.

The role of air conditioning sensors

1. Internal machine ambient temperature sensor: mainly detects the ambient temperature in the room and controls the start and stop of the air conditioner.

2. Internal unit coil sensor: It mainly detects the internal unit tube temperature, prevents cold wind in winter, and defrosts the external unit. (Some are external machine tube warming cream)

In summer, the internal unit is protected against 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 the hook is fixed on the evaporator);

One is to put the cold air probe when the air conditioner is heating, on the indoor unit evaporator;

One is the air conditioning heating automatic defrosting probe, which is on the outdoor unit condenser.

Open the panel of the internal unit, take out the filter, and see a black small head attached to the evaporator of the internal unit. This sensor is the temperature sensor of the internal unit.

If you open the cover of the electrical box, and the temperature sensor, and insert the temperature head into the evaporator tube of the internal machine is the tube temperature sensor. Different styles have different positions.

On-hook: room temperature sensor, open the panel of the internal unit, and take off the filter to see it.

The tube temperature sensor, which is combined with the room temperature, needs to open the cover of the internal unit, remove the electrical box, and insert it in the evaporator.

Cabinet: room temperature sensor, open the lower panel, on the side of the wind wheel.

The tube temperature sensor needs to be fully opened and inserted in the evaporator.

Price of air conditioning sensor

The price of the air-conditioning sensor is 0.01 yuan to 220 yuan. (The price source network is for reference only.)

What is the price of the air conditioner sensor in the market, how does the air conditioner sensor work, and what is the main role of the air conditioner sensor? These editors have given you a detailed introduction in the above, everyone see After finishing the above content, it should be clearer the basic information of the air conditioner sensor. The use of air conditioner sensors can sense the temperature of various components of the air conditioner, so as to better control the environment and give people a comfortable indoor environment.

If you want to know more, our website has product specifications for air conditioning sensors, you can go to ALLICDATA ELECTRONICS LIMITED to get more information