It is quicker to wire them in your scenario than any other way. As you add LEDs to your parallel array, the voltage requirements stay the same. As you add LEDs to your parallel array, the current requirements increases the amount that each LED requires (5 LEDs @ 20mA = 100mA requirement/draw). 100 Ohm 1/4 watt resistor. 470 ohms (1 piece) Start by hooking all four resistors in series (in a string). Resistance adds when you hook resistors in series, so you'll have an overall resistance of 910 ohms to start with. Hook the mess in series with your LED, and hook it all up to 24 volts. Now take your voltmeter and measure the voltage across the LED lamp. A quick explanation of the resistors chosen: Assuming a nominal 12V supply, the 15Ohm resistor will allow a current of 0.8A. The power dissipated by the resistor will therefore = V*A = 12*0.8 = 9.6W, thus making the 10W rated resistor sufficient (particularly when installed with a means to transfer heat away). LED Resistor Calculator. To calculate the resistor needed for a simple LED circuit, simply take the voltage drop away from the source voltage then apply Ohm's Law. In other words where: V S is the source voltage, measured in volts (V), V LED is the voltage drop across the LED, measured in volts (V), Vay Tiền Nhanh Chỉ Cần Cmnd Nợ Xấu.

do 12v leds need resistors