LED CONNECTING INSTRUCTIONS BEFORE CONNECTING YOUR LEDS IN A CIRCUIT YOU SHOULD KNOW A LITTLE OF OHMS LAW, A FEW BASIC FORMULARS ARE ALL YOU NEED. WIRING INFORMATION LED CONNECTING INSTRUCTIONS. Leds last several hundreds of hours longer than lights bulbs and consume less power, also much cheaper to run.Leds operate from Direct Current ( DC ) not from Mains ( AC ).The operating voltage of an led is approx 1.5 to 5 volts dcdepending on colour. Using a mains to 12 volt dc transformer ispopular, all you need is to reduce the 12 volts by connecting aresistor to the long led ( positive ) of the led to drop 12 volts dcto the working voltage of the led.The use of leds in the home, car, caravan or boats is very easyand safe. Leds have many applications. When you buy leds make sure you know two basic facts. The forward voltage ( Vf ) that is the leds working voltage. The operating current ( m/a ) the current the led draws. There are two ways that you can connect leds. 1. Series 2. Parallel We will use 12 volts as the supply in the following examples. Example 1. Using 1 ledYou have a led with a forward voltage of 3 volts, take that away from 12 volts, the answer is 9 volts, this is the amount you have to drop across a resistor. To calculate what resistor you require you need to divide the leds operating current into the 9 volts, in this case the leds operating current is 20 m/a . 20/1000. 9 / 20 = 0.45 x1000 = 450 ohm resistor.This resistor would be connected to the long leg of the led positive , the other end of the resistor is connected to positive12 v supply, the short leg of the led is connected to the negative12 v supply. Example 2. Leds in series When connecting leds in series, to find how many you can run from 12 volts you need to add the leds operating voltage together, If we have 3 leds to connect in series each with a forward voltageof 3 volts x 3 = 9, take the 9 volts away from 12 v = 3 volts. The 3 volts is the amount you have to drop with a resistor. To do this each led has a current of 20 m/a x 3 = 60 m/a.Divide 60 m/a into 3 volts = 50 ohm resistor. Connect the long leg of the first led to the resistor, the short legs connected to the long leg of the second led, the second led short leg is connected to long leg of the third led, the short leg of the third led is connected to 12 negative, the other end of the resistor is connect to 12 volts positive. Example 3. Leds in parallel CONNECTING LEDS IN PARALLEL ALLOW YOU TO CONNECT AS MANY AS YOU LIKE UP TO THE OUTPUT CURRENT RATING OF THE SUPPLY. WORK OUT RESISTOR VALUE AS ABOVE. TAKE CARE IF YOU HAVE TOO MANY RESISTORS IN A CONFINED SPACE, THEY COULD GET WARM. |
3mm COLOUR DIFFUSED FOR 3 TO 14
