25 2.2.9 LDR (Light Dependent Resistor) LDR Transistors Backlight LCD, RGB LED, transistors. EE389 Electronic Design Lab Project Report, EE Dept, IIT Bombay, Nov 2009 Fully-automated control of lighting and security system of a Room Group No: D2 Bharat Bhushan (06d04026) Sravan. Apa itu Light Dependent Resistor (LDR)? LDR yang juga dikenal sebagai photo resistor, photo conductor, atau photo conductive adalah komponen elektronik yang nilai resistansinya meningkat saat dikenai intensitas cahaya, dan menurun saat kondisi gelap. Adapun simbol untuk LDR ditunjukkan It stands for Light Dependent Resistor or Photoresistor, which is a passive electronic component, basically a resistor which has a resistance that varies depending of the light intensity. A photoresistor is made of a high resistance semiconductor that absorbs photons and based on the quantity and Solicit examples of how a light sensitive sensor could be used for this purpose. The photoresistor can be passed around and the variation in size noted (Image 2). Ask students to design and describe two applications that make use of the light dependent resistor, voltage divider circuit that was built. 2. INTRODUCTION • A light dependant resistor(LDR) or a photoresistor or photocell is a light controlled variable resistor. In other words, it exhibits photoconductivity. • The resistance range and sensitivity of a photoresistor can substantially differ among dissimilar devices. contd. Light dependent resistor (LDR) based low cost light intensity measurement circuit design (lux meter) has been proposed which is a better replacement for the current high cost light intensity meter. The working principle of this circuit is based on the individual principle of a single 741 Op-Amp A Light Dependent Resistor (LDR) is also called a photoresistor or a cadmium sulfide (CdS) cell. The basic structure of an LDR is shown below. The snake like track shown below is the Cadmium Sulphide (CdS) film which also passes through the sides. Light-dependent resistors (LDRs) are the key to building automated lighting. LDRs are useful and inexpensive, making them an This application is just one example of how to use these versatile sensors in your project. Jeremy S. Cook is an engineer who has worked in manufacturing automation Light Dependent Resistor (LDR) also known as Photoresistor. This project demonstarate how to use LDR in Arduino. The Value of LDR changes with the Light Exposed. This example demonstrates how to use LDR as a switch; each time you cover the LDR, the LED is turned on (if it's off), and off (if 1 light dependent resistor (it doesn't matter which one, you don't even need to know the part number). 5 kilo ohm resistor. In theory, you could use any resistance value, but I chose 5 kohm because the resistance of the LDR was in the order of a few kilo-ohms under typical room lighting conditions. Dependent Sources A dependent source is one whose value depends on some other variable in the circuit. Where g is a constant with the units of A/V. So the current that flows into the output circuit depends on the measurement of a voltage on the input circuit. Dependent Sources A dependent source is one whose value depends on some other variable in the circuit. Where g is a constant with the units of A/V. So the current that flows into the output circuit depends on the measurement of a voltage on the input circuit. 2. Resistors. A resistor is