CHOOSING A RIGHT RESISTOR FOR A SIMPLE LED CIRCUIT
Hi friends, Today, many people know what is a resistor . Yeah! it is a current limiting element which is used almost in every electronic circuits in order to limit the the flow of current in those circuits. But, People will get confused in how to choose a right resistor for a circuit..! Here, Let me tell you how? consider an 8 mm LED whose forward voltage is 3.5 v and the average current required for the LED to glow is 150 mA which is approximately equal to 0.150 Amps.And consider a battery of 9V DC power supply Now, If you connect the LED to the battery the LED will blow off. To prevent that you have to introduce a resistor(R) to the circuit. In order to calculate the resistance R. R= (supply voltage-required voltage)/Required current R=(9-3.5)/0.150= 36.6 ohms. Therefore, the required rate of the resistor is 36 ohms.
