MORE RELATED

GROOMIX INFO
Blogs & Articles
MENU
. . .

Working Principle

views : 228

LDR Controlled Transistor switching

LDR Controlled Transistor switching is a type of switching in which ON-OFF (switching) of transistor is controlled by LDR (Light Dependent Resistor). That’s means, switching is done in according to presence of light around the LDR sensor. This type of switching arrangement is used in various automatic switching like street light automatic switching, emergency lamp etc.

Image : 1 inverted circuit diagram of LDR Controlled Transistor switching

Inverted and non-inverted switching circuits

The arrangement shown in image : 1 is an inverted type. Here, when light is falls on LDR sensor, its resistances decreases which results in decreasing in voltage drop across it. Due to which, voltage across the Base of the transistor decreases and when it drops below 0.7V (Si) or 0.3V (Ge),then npn transistor is turn OFF ( Reverse in case of pnp transistor). Here output is connected to LED light as a load. When light will fall on LDR, output LED will be OFF.

In non-inverted (shown in image :2), when light falls on the LDR sensor, its resistance will be decreases which results in drop of voltage across it. Less voltage drop across LDR sensor result in more voltage across resistor which turns on the npn transistor. Hence, in this case, when light fall on LDR sensor, LED will start grow.

Image : 2 non-inverted switching circuit diagram

Posted By :
Mr. Unique

2016-10-26/02:06:48

Share this Page

Comments...

More :Working Principle

Working Principle
Working Of Electromagnetic Relay
views :102
Working Principle
LDR Controlled Transistor switching
views :228
Working Principle
working of LDR sensor
views :84

Latest Updates

Breaking News
Best internet Recharge Plans than jio..!
views :74
Engineering Project Ideas
Vehicle Theft Protection Using Gsm
views :96
Engineering Project Ideas
DTMF Controlled Robot or Mobile Controlled Robot
views :58
Engineering Project Ideas
Digital Clock With Home Appliances Control Using Microcontroller
views :49
Engineering Project Ideas
Cooking Monitor
views :62
Engineering Project Ideas
Boundary Security System(Wireless)
views :71
Engineering Project Ideas
Automatic Garage Parking System
views :76
programming
Arduino UNO tachometer coding with variable resistor and DC motor speed control
views :74
Engineering Project Ideas
Employee Details Recording Interface synopsis
views :107
Engineering Project Ideas
Footstep Power Generation
views :60

---More To Do---

This pages is developed to give users a genuine web materials of all types throughout the world. Many articles, by experts are publishing here, every hours. You can publish your topics as well as you can comment on all posted topics and learn more. Many types of topics are published here like Technology based ( Electronics, Electricals, Mechanicals, civil engineering, computer science, programming and software development, Assemply language codings), Health like medicine, healthy diets, Homeopathy etc) and many types of latest news updates.


All content, design, and layout are Copyright © 2016 - Digital Photography Review All Rights Reserved. Reproduction in whole or part in any form or medium without specific written permission is prohibited.

MORE TO DO