 # Question: Should I Put A Resistor Before Or After The LED?

## Can I connect a LED directly to a battery?

LED (light emitting diode) lights are low-current electronic components.

As such, they cannot be connected directly to a typical household battery without running the risk of burning out from too much current..

## What is the maximum voltage a LED can withstand?

about 3.0 voltsThe maximum voltage applied it a single white LED is about 3.0 volts. Several LEDs in series can match a higher voltage supply, or a resistor (or other current limiting circuit) can be used to limit the current.

## What happens if you put too much voltage through an LED?

The answer to your title question is: The LED will light up. … Too much current will blow the LED. You limit the current to your desired value (often 15 to 20mA) by putting the correct resistance into the circuit. Use Ohm’s law to work that out.

## Why do LEDs need current limiting resistors?

A current limiting resistor helps mitigate the effect of voltage increases by virtue of its linear IV curve. Additionally, resistors behave oppositely from LEDs in relation to its temperature – as temperature increases, resistance also increases.

## Will a 9v battery power a 12v LED?

that is no problem . you can use 9v battery for 12v Led . Just only the brightness is less than 12v battery .

## How many LEDs can a 12v battery power?

The answer should be the source voltage divided by the voltage drop of 1 LED. So if your source is 12v, and your LEDs have a voltage drop of 3.5, 12/3.5v, gives you 3 LEDs. If the the forward voltage drop of the LEDs was exactly 3 volts, you’d be able to drive 4 of them, and would not need a current limiting resistor.

## Does it matter where you put a resistor?

Resistors are just materials which give electrons a hard time to move through them. Slows them so to speak. Think of it as a bumpy section on a highway. It doesn’t matter which direction you are going, you will have to slow down anyway.

## Do I need a resistor for a 12v LED?

Originally Answered: In order to light an LED with a 12V, what resistor value is needed? Normally, you want to minimize waste, so you connect as many LED in series as possible to consume the voltage provided, then you use a resistor to limit the current to the correct value. White LEDs are universally using 3.0 volts.

## What happens when an LED is directly connected to a power supply?

When LED is connected to a power supply with a voltage higher than its forward voltage, a current limiting resistor is connected in series with the LED. The current limiting resistor limits the current for the LED and regulates the difference in voltage drops between the LED and the power supply.

## What happens if I use the wrong resistor?

If you are using such a resistor in a current-sensing application in a switch-mode circuit, you will get spurious readings or inaccurate behaviour. … For a simple LED circuit there are no bad consequences of using a resistor of higher power.

## Why is a resistor connected before ground?

Their purpose is to pull a node voltage down to GND (or up to VDD) if the node is not driven. If the node is driven to a certain voltage then the driving voltage source should provide enough current to flow through the resistor. That is why the value of such resistors are chosen to be ~100kohm.

## What happens if you don’t use a resistor with an LED?

Diodes are current devices. Once the voltage across the diode reaches its forward turn on voltage, the diode conducts and its forward resistance becomes very low. … If you don’t put a resistor in series with the LED and you apply power, the current through the LED will exceed its rating and it will be destroyed.

## Do resistors go on positive or negative side of LED?

Since this resistor is only being used to limit current through the circuit, it can actually be located on either side of the LED. Placing the resistor on the positive (anode) side of the resistor will have no differing effects from placing the resistor on the negative (cathode) side of the LED.

## Do I need a resistor for LED?

Resistors in Light Emitting Diode (LED) Circuits An LED (Light Emitting Diode) emits light when an electric current passes through it. … The ballast resistor is used to limit the current through the LED and to prevent that it burns. If the voltage source is equal to the voltage drop of the LED, no resistor is required.

## Why do you need a 330 ohm resistor for an LED?

330 ohms may be used by some people as a “get you going” value that works “well enough” in many cases. The purpose of the resistor is to “drop” voltage that is not required to operate the LED, when the LED is operating at the desired current.

## What resistor do I need to reduce voltage?

To reduce voltage in half, we simply form a voltage divider circuit between 2 resistors of equal value (for example, 2 10KΩ) resistors. To divide voltage in half, all you must do is place any 2 resistors of equal value in series and then place a jumper wire in between the resistors.

## What resistor should I use with my LED?

Basics: Picking Resistors for LEDsPower Supply VoltageLED ColorResistor (rounded)5 VRed, Yellow, or Yellow-Green150 Ω5 VRed, Yellow, or Yellow-Green56 Ω9 VRed, Yellow, or Yellow-Green75 Ω9 VBlue, Green, White, or UV100 Ω4 more rows•Aug 29, 2012

## Does resistor drain battery?

The power consumed by your circuit determines how fast the battery drains. … Since the voltage doesn’t change, when the resistance goes up, the current and the power go down. So, adding series resistance to the circuit will make your battery last longer.