MullOverThings

Useful tips for everyday

# How do you know which resistor should I use?

## How do you know which resistor should I use?

A rule of thumb is to find a resistor with twice the power rating. Here I would choose a 250 mW resistor since those are the most standard ones. Usually, you can just use the cheapest resistor you can find with the correct power rating.

## Can I use 1K resistor for LED?

SIMPLE & BEST ANSWER: Use 1K (1000 ohm) 1/4W resistor for any LED. Unlike bulbs, LED BRIGHTNESS DOES NOT VARY DRAMATICALLY with wide variations in current.

## Do I need resistor for LED strip?

In addition to the LEDs, one or more current limiting resistors is also necessary to ensure that the LED strip does not go into overcurrent mode. The resistor is also placed in series with the LEDs, and its resistance value is calculated such that it will draw approximately 3 volts as well.

## Do 12v LEDs need resistors?

LEDs can be ran off multiple voltages, but a series resistor is required to limit the current in the circuit. Too much current in an LED will destroy the device. As with all diodes, LED’s will only allow current to flow in the direction from the anode to the cathode.

## Should resistor go before after LED?

It doesn’t matter! The resistor can go before – or after – the LED, and it will still protect it. the current that flows out of a battery is always equal to the current that flows back into the battery. The current through the resistor is the same as the current through the LED.

## What happens if I use a higher ohm resistor?

The cases where using a higher value resistor will damage a circuit exist, but are a bit less usual than the cases where it may simply produce a weaker result than desired, or a different frequency response than desired.

## What resistor do I need for 5v LED?

Basics: Picking Resistors for LEDs

Power Supply Voltage LED Color Resistor (rounded)
4.5 V Blue, Green, White, or UV 51 Ω
5 V Blue, Green, White, or UV 68 Ω
5 V Red, Yellow, or Yellow-Green 150 Ω
5 V Red, Yellow, or Yellow-Green 56 Ω

## Can LED strips catch fire?

The possibility of led strip lights catching fire is minuscule, even though they are hot to touch. Incandescent bulbs have a filament that emits excessive heat, the light sources can ignite a fire on overheating, but as LED lights produce light at a lower temperature, they don’t catch fire as easily.

## What happens if no resistor?

If there really were no resistance in the circuit, the electrons would go around the circuit, and arrive back at the beginning of the circuit with as much energy as the potential difference (the voltage). That final energy is usually what is dissipated as heat or other types of energy by the circuit.

## What resistor do I need for 3V LED?

Basics: Picking Resistors for LEDs

Power Supply Voltage LED Color Resistor (calculated)
3 V Red, Yellow, or Yellow-Green 48 Ω
4.5 V Red, Yellow, or Yellow-Green 36 Ω
4.5 V Blue, Green, White, or UV 48 Ω
5 V Blue, Green, White, or UV 68 Ω

## How is the value of a led resistor determined?

But there are some factors that determine the LED resistor values! The voltage source, voltage drop, current, and even the color of LEDs are the factors that determine the value of the resistor. Before doing the calculations you must know the relation between voltage, current, and resistance.

## What kind of resistor do I need for red LED?

The operating voltages of different LEDs vary with wave-length of color. Red needs a very low turn ON voltage than green and blue. Example 1: Find the required resistor for a Red LED in a 12 V supply.

## How is the current through a led measured?

I LED is the current through the LED *, measured in Amperes (Amps/A), and R is the resistance, measured in Ohms (Ω). * The current through the circuit is constant so ILED is also the current through the resistor. This calculator is based on the Ohms Law Calculator, but takes into consideration the voltage drop from the LED.

## What is the formula for calculating the resistor value?

Formula for calculating resistor values. The voltage across the rail Vs is equal to the sum of voltages across the LED and resistor. Given the forward voltage of the diode Vf, the voltage across the resistor is equal to Vs –Vf.