该帖子通过了解其数据表，引脚和其他技术规范，如何制作LM35应用电路。
By: SS kopparthy
LM35主要规格
The IC LM35 is a temperature measuring device that looks like a transistor (most popular package is TO-92 package).
在需要测量温度的大多数电路中找到该设备，因为该装置是低成本，可靠的，并且精度高达+ -3 / 4摄氏度。
The low cost of the sensor is because of its wafer-level trimming and calibration.
由于温度测量的准确性，该IC比热敏电阻好得多。
Pinout Details
As you can see in the above figure, the LM35 IC consists of three pins out of which two are for powering the sensor and the other one is the output signal pin. The sensor can work anywhere from -55 to 150 degrees Celsius.
The output temperature is directly proportional to the temperature change in Celsius. Also the other variant LM35C is available and its temperature range is -40 to 110 degrees Celsius.
Technical Specifications and Features
This device gives out 10mV per degree Celsius rise in temperature.
该设备仅消耗60μA电流。因此，它不会从电池或电源中排出大部分电力。
而且，由于这种低电流，装置的自加热低至0.1°C。
该装置的其他具有不同包装的变型也可提供，例如至-46和220。
这些与传统的工作相同，但在他们的使用领域不同，以及特定应用的可行性。
例如，对于-46金属封装可用于测量表面温度，因为金属封装可以直接与温度需要测量的表面接触，而TO-92封装可能不会随着器件测量温度基于器件的端子的温度，因为金属端子比塑料壳体的温度更多。
因此，TO-92封装的LM35用于测量大部分电路中的空气温度。
框图和内部功能
The above image shows the internal block diagram of the IC LM35. Here we can see that the IC is internally configured around a couple of opamps A1 and A2. The first opamp A1 is configured as an accurate temperature sensor through a feedback loop formed by a couple of BJTs configured as a current mirror.
电流镜确保完美线性和稳定的温度检测速率，并防止输出处的误触发或不准确的温度读数。
感测温度以每度摄氏度为8.8mV的速率在电流镜的发射极侧产生。
输出是应用to a buffer stage using another opamp A2 which is configured as a high impedance voltage follower.
该A2级用作缓冲器以加强温度到电压转换，并且通过配置为发射器跟随器的另一个高阻抗BJT级，将其呈现在IC的最终输出销。
The final output thus becomes highly isolated from the actual temperature sensor stage and delivers highly accurate temperature sensing response, which can be used by the user with an external switching stage such as a relay driver stage or a triac.
Using a Heatsink
传感器LM35集成电路也可以焊接加热ink fin to increase the accuracy and to decrease the sensing and response time in slowly moving air.
要更好地了解，让我们来看看使用LM35的以下电路，以指示温度高于指定级别：
温度检测电路使用LM35 IC
LM35电路使用OP-AMP IC741作为比较器。OP-AMP配置为非反相放大器。
That means when the LM35 detects high temperature, the output of the op-amp becomes +ve and the red LED lights up and the temperature falls below the specified level, the output of op-amp becomes –ve and the green LED lights up.
The high temperature level can be set with the help of preset in the circuit.
要设置红色LED亮起的温度水平，您需要知道电路正在测试的实际温度。为此，您可以使用万用表。
As we know that the LM35’s output voltage increases 10mV per degree Celsius rise in temperature, we can use the multimeter to measure the output voltage and for example the voltage is 322mV, then the temperature at the place is 32.2°C.
You can even test the IC if it’s working or not using the above procedure. You can measure the actual temperature using an atmospheric thermometer and compare it with the values obtained with the LM35. You might not get the exact values but you should get close values.
LM35继电器控制电路
An accurate LM35 based temperature controller can be built for controlling an external load such as a heater or a fan by attaching a relay driver stage to our previous as shown below:
在理解上述LM35电路的工作原理后，您应该理解LM35几乎在电路中运行。
The circuit doesn´t work.
find the mistake in your circuit, it will surely work…do it stagewise
I make this circuit and working fine.but in few seconds the ic75 become too hot.what is the reason?i used 12 volt 1amp transformer supply .and converted it in to dc
这很奇怪，因为IC被评为以12V ......，使用7812 IC用于整个电路并再次检查。
Why lm35 is very easy damaged during testing at first I used 5 volt input and measured wit DMM at output was millivolt 10mv/c° was corrected, after I tested many times output voltage became many thousands millivolt and not correct.
Sorry, that shouldn’t happen. At 5V across pin#1 and #3 can never damage the IC no matter how many times you connect as long as the polarity is right. Sometimes the device is duplicate in quality and may cause such problems.
请我一个学生我想要制作温度控制常规风扇，但我正在考虑使用热敏电阻作为传感器，但我在搜索谷歌搜索时遇到了这个网站，我需要一些传感器选择的建议我的关注
您可以尝试从上述文章中的最后一个电路。调整预设，直到继电器只需点击所需的温度大气温度即可。现在将设备保持在快速移动的风扇附近，并检查继电器是否咔嗒声。
谢谢我用lm35做到了它，一切都在正如所规定的lm35输出正常的情况下，每厘米10mV，并且没有加热，非常敏感
Glad you could solve it….hope you enjoy the circuit now!
设计LM35传感器电路N复杂，如果我们设计，我们可以获得多少效率N与LM35传感器相比输出的任何变化
It is very simple to build a temperature sensor with LM35, and the efficiency can be expected to be optimum and as per the expected results. The output tripping will be very accurate if the op amp is set correctly.
Can an lm35 be used as a transistor or is it only for temperature measurement?
it can be used only as a temperature sensor.
thank you for the reply.
我如何理解To92 Packge中的铭文，例如：52AB或850RC，如果我有国家的相同参考LM35DZ？谢谢。