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DS18B20 is the first Dallas company to launch a "single wire bus" interface to the numerical temperature sensor. There are only three interfaces to a power VCC a ground GND and a data DQ interface. In the VCC power supply range is very wide in the case of 3-5V power supply can work. GND is the need to connect to the copper microcontroller to the ground. DQ for data interface, used to communicate with the microcontroller, the hardware circuit design generally need to pull 4.7K pull-up resistor in order to communicate with the microcontroller. In function DS18B20 as a digital temperature sensor with high accuracy can reach 0.0625 degrees Celsius accuracy. The test temperature range can reach 55 to +125 DEG C. Widely used in a variety of temperature measurement occasions such as ambient temperature detection, air conditioning temperature detection control.
DS18B20 digital temperature sensor wiring convenience, packaging can be applied to a variety of occasions, such as pipe type, screw type, magnet adsorption, stainless steel packaging, variety, LTM8877, LTM8874, etc.. Mainly according to the application of different and change its appearance. Encapsulated DS18B20 can be used for cable trench temperature measurement, blast furnace water cycle temperature measurement, boiler temperature measurement, room temperature measurement, agricultural greenhouse temperature measurement, clean room temperature measurement, ammunition temperature measurement and other non limit temperature occasions. The utility model has the advantages of abrasion resistance, small volume, convenient use and various packaging forms, and is suitable for various narrow space equipment digital temperature measurement and control fields.
1, technical performance description:
Unique single wire interface, DS18B20 in the connection with the microprocessor requires only one mouth line to achieve two-way communication between the microprocessor and DS18B20.
Second, the measuring range of 55 to +125 DEG C, the inherent error of temperature (note, not resolution here before is wrong) 1 C.
Third, support multi-point network function, multiple DS18B20 can be connected in parallel to the three line only, only a maximum of 8 parallel, multi-point temperature measurement, if the number is too large, will make the power supply voltage is too low, resulting in unstable signal transmission.
The working power supply: 3.0~5.5V/DC (data line parasitic power supply)
Fifth, does not require any external components in use
The measurement results with 9~12 bit digital serial transmission mode
The stainless steel protective tube diameter 6
It is suitable for DN15~25, DN40~DN250, a variety of media industry pipelines and small space equipment temperature
9, the standard installation thread M10X1, M12X1.5, G1/2 optional
The PVC cable, direct wire or German ball type connection box outlet, easy to connect with other electrical equipment.
2, wiring method
In the face of the flat side, left negative right, once the counter will immediately heat, it may burn! At the same time, the reverse is also the cause of the sensor is always displayed 85 degrees Celsius reasons. The actual operation will be positive and negative connection, the sensor immediately heating, LCD screen can not display the reading, positive and negative after a good display of 85 degrees C. In addition, if the use of 51 MCU, then the middle pin must be connected to the 4.7K - 10K of the pull-up resistor, otherwise, due to the high level of normal input / output, display 85 degrees or immediately after power, with a few months after the temperature of 85 DEG C and the normal value on or about.
3, characteristics
A unique interface, requires only one line communication multidrop capability simplifies distributed temperature sensing applications, no external components available data bus power supply voltage range from 3 V to 5.5 V without a standby power supply measuring temperature range for -55 C to +125 c.. Fahrenheit is equivalent to -67 degrees F to 257 degrees Fahrenheit -10 degrees C to +85 degrees C range accuracy of + 0.5 degrees C
Programmable temperature sensor resolution is 9~12, the temperature is converted to 12 bit digital format to a maximum of 750 milliseconds, nonvolatile temperature alarm settings the user can define the application scope, including temperature control, industrial systems, consumer electronics, thermometer or any heat sensitive system
Description the DS18B20 digital thermometer provides 9 to 12 bits (programmable device temperature readings). Since DS18B20 is a port line communication, the central microprocessor has only one port connection with the DS18B20. For reading and writing and temperature conversion can be obtained from the data line itself, without external power supply. Since each DS18B20 contains a unique serial number, multiple ds18b20s can exist simultaneously on a single bus. This allows temperature sensors to be placed in many different places. It has many uses, including air conditioning control, building temperature sensing equipment or machinery, and process monitoring and control.【转载请注明出处：https://www.5ubs.com/bsTemplate/fanyi/523.html】 |
