Sunday, September 23, 2012

HEAT SENSOR



Components Required :


   *  9V Battery - 1
   *  3.3K ohm Resister - 1
   *  100 ohm Resister - 1
   *  BC548 Transistor - 1
   *  Electronic Buzzer - 1
   *  110 ohm Thermistor – 1
   *  Switch (optional) - 1
   *  4.7 V Diode - 1





Know about Components :


* Thermistor  : It is also called as Heat sensor. According to the Heat, the resistivity increases / decreases.

* BC548  : It is a Bi-Polar Transistor with 3 terminals. When any input is given to the base terminal, the connection exists between the emitter and collector terminals.

* Buzzer : When connecting it to any battery, u will hear a musical sound or a buzzer sound. 


Description :


Connect the Components as shown in the circuit. 

In this circuit, according to the Heat on Thermistor, the Buzzer will sound like alarm. 

This is because, when the Thermistor gets heated a voltage passes to the Base of the Transistor and the  Junction between emitter and collector gets connector and Buzzer will be ON.

Diode is used here to prevent back Emf.    

Hence HEAT SENSOR Module  is ready.


Pin Diagram of BC548 :















START TESTING YOURSELF !!!

AUTOMATIC STREET LIGHT CONTROL


Components Required :

   *  9V Battery - 1
   *  50K ohm Resister - 1

   *  470 ohm Resister - 1
   *  IC555 - 1
   *  LED (any color) - 5
   *  LDR (Light dependent Resistor) - 1
   *  Switch (optional) - 1
   *  Connecting wires (Required)



Know about Components :

   * IC555   : It is a timer IC used to give some delay to the circuit. It is most commonly used IC 
for timer circuits.

   * LDR     : It increases / decreases resistivity according to the light falling on it.



Description :

   Connect the Components as shown in the circuit. 


   The circuit is simple, so sure you will be getting the output. 


   In this circuit, according to the light falling on LDR, the LEDs  will GLOW or OFF. 


   If light falls on LDR, the LEDs connected in series will be OFF.   


   If light do not  falls on LDR, the LEDs connected in series will be ON (glow).

   In the day time, the LEDs will be in OFF and at night time it automatically starts Glowing.    


   Hence AUTOMATIC STREET LIGHT CONTROL project is ready. 


IC555 Pin Description :














START TESTING YOURSELF !!!