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sensors

Sensors:


Let us say the person be X whose mother tongue is hindi and the other  person be  Y whose mother tongue is tamil. Now the person X cannot understand what the person Y says,  similarly the person Y cannot understand what the person X says. Now to make the understand each other we need to have an intermediate person to translate their languages. An intermediate person role is to make them communicate and understand better. The same role is here for the sensor it connects the device and the controller.

What is sensor? 


Sensor is a device which  converts the physical signal to electrically measurable signals. The variation in the signals and the response of the devices are based on the changes in the environment. By the way it coordinates the device and the controller

What are physical signals? 


The physical signals may be:

  • Temperature
  • Light
  • Blood pressure
  • Humidity
  • Speed
  • Smoke.  e.t.c
Types of sensors: 

Let us see the types of sensors in detail: 

Temperature sensor: 


It is used to convert the temperature into electrical signal. If the Temperature changes in the environment is detected, sensor will send that value to the microcontroller. If the value measured is normal to the reference value it won't respond,  in case of any abnormal value to the reference value it will indicate us .

LM35 is the mostly used temperature sensor. Rarely we used LM34

LM35: 

LM35 is a temperature sensor which produces voltage output in linear proportion to the degree celsius of heat. 


LM35 pin configuration: 


Every sensor will have two or more terminals so it is necessary for us to know the pin configuration. 

  • Vcc  / Vs:  supply voltage
  • Analog output:  10mv/°c
  • GND 


Features of LM35: 

  • Minimum voltage: -2 V
  • Maximum voltage:  32v 
  • Typical voltage:  5v
  • Drain current is always less than 60mua
  • Rise of 10mV for every increase in 1°C
  • +/- 0.5 Accuracy

Application: 

  • Helps in measuring temperature of a particular environment
  • Provides the thermal shutdown for a circuit/component
  • Monitors Battery Temperature
  • HVAC applications. 

LM34: 

LM34 is a temperature sensor which produces voltage output in linear proportion to the Fahrenheit.

The pin description of LM34 is similar to LM35

LM34 features:

  • Linear +10.0 mV/˚F scale factor
  • 1.0˚F accuracy  (at +77˚F) 
  • Suitable for remote applicationsL
  • ow cost due to wafer-level trimming
  • Operates from 5 to 30 volts
  • Drain current is always less than 90 µA L
  • Low self-heating
  • Nonlinearity only ±0.5˚F typical
  • Low-impedance output

To know the connectivity of Arduino with LM35 refer my blog

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