At a basic level, load resistors are purpose-designed for installation in vehicles where problems result from L.E.D replacement of standard incandescent globes. Suitable for indicator and brake light circuits, LED load resistors are designed to draw the same current as a 21-watt incandescent globe, correcting any problems with low current draw LED Current Limiting. Resistors are key in making sure LEDs don't blow up when power is applied. The typical forward voltage is the voltage which is required to make an LED light up, and it varies (usually somewhere between 1.7V and 3.4V) depending upon the color of the LED. A pull-up resistor is used when you need to bias a Pull-down resistors work in the same manner as pull-up resistors, except that they pull the pin to a logical low value. They are connected between ground and the appropriate pin on a device. An example of a pull-down resistor in a digital circuit can be seen in the following figure. Pull-down resistor. In this figure, a pushbutton switch is Dimming an LED light is, add a resistors to the connection or even several resistors, to ensure you get the right brightness, this is called analog dimming. There is probably already a resistor in the line to drop the 12V, so the actual value you need is probably less than 10K. Now, we get to the tricky part: some LEDs will begin to dim The main reason LEDs need resistors is to protect the LED from excessive current which can permanently damage the LED. LEDs have current ratings which indicate the optimal current at which the LED operates effectively. 1. Temperature Increases On The LED Light. The main purpose of fixing resistors in an LED circuit is to control the amount of voltage that goes into your light, so if you don't fix a resistor then it will be difficult for the LEDs as they could receive too much current and power. For instance, let's say we fixed our 2 volts through a 1-ohm A colored LED will also work on less voltage, but you have to use a smaller resistor. (100 ohms works well for 4.5VDC) The LEDs that you found that said they didn't need resistors were probably a package unit that had them built in. Most modelers use the 'component LEDs' (my word) which are just the plain LEDs without anything else wired to them. ll95a.

do 12v leds need resistors