# Do LEDs Need Constant Current?

## Are 12v LEDs brighter than 5v?

5V is brighter than 12V as the 12V bullet pixels use half the current to stay somewhat close to 5V efficiency.

Close, but 5V is still more efficient.

So a 5V display will be brighter and use less power than a 12V display..

## What resistor do I need for 12v LED?

Resistor = (Battery Voltage – LED voltage) / desired LED current. So assuming a 12 volt power source and a white LED with a desired current of 10 mA; The formula becomes Resistor = (12-3.4)/. 010 which is 860 ohms. Since this is not a standard value I would use an 820 ohm resistor.

## How does a constant current LED driver work?

Constant-current drivers power LEDs that require a fixed output current and a range of output voltages. … In these LEDs, the current is already regulated, either by simple resistors or an internal constant-current driver, within the LED module. These LEDs require one stable voltage, usually 12V DC or 24V DC.

## Do LEDs get brighter with more voltage?

Adjusting the voltage lower or higher will change the brightness, but only because it also changes the current- higher voltage means the current will increase in an LED.

## 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.

## Are LEDs voltage sensitive?

Because LEDs are extremely sensitive to under- or over-voltage, you must calculate voltage drop carefully and correct for it. … Sometimes it works as if the source is an incandescent lamp; other times, if the voltage is too low, for example, standard dimmers do not work.

## Do LEDs need drivers?

Do LEDs Need a Driver? Most LEDs require a driver, a few are designed to run on AC current. … Most household LEDs that are direct replacements for incandescent, halogen, and CFL bulbs with an E26/E27 or GU10/GU24 base have an internal driver. It’s the strip lights where people trip up.

## How many LEDs can run on 12v?

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.

## Can I use 12v transformer for LED?

FAQ – 12V Transformers and LED Compatibility. Magnetic transformers will generally work with all MR16 LED lights, albeit at the cost of efficiency and extra power consumption as was explored in this FAQ article. … They are not suitable for 12VAC (halogen or LED retrofit) lighting.

## Do I need a special transformer for LED lights?

Do LED Bulbs Need a Transformer? All mains powered LED bulbs require a transformer. Depending on the bulb type, the transformer/driver may be built in to the bulb casing or may be located externally.

## How do I choose a LED power supply?

How to choose a power supply for your LED strip projectStep 1: Determine the LED strip voltage. The first step is to figure out what the voltage of the LED strip is. … Step 2: Determine the power draw of the LED strip. Next, look for either a wattage (W) or amperage (A) specification for the LED strip. … Step 3: Determine the connection method.

## How many volts can a 5mm LED take?

Calculating an LED resistor value VL = LED voltage (2V, or 4V for blue and white LEDs). The LED current must be less than the maximum permitted for your LED. For standard 5mm diameter LEDs the maximum current is usually 20mA, so 10mA or 15mA are suitable values for many circuits.

## What is the difference between a LED driver and a transformer?

12VAC Electronic Transformers and LED Drivers They differ in output and load compatibility i.e. which LED lights they will work with. The fundamental difference between the two is that LED drivers output DC while electronic halogen transformers output 12VAC.

## How much current does an LED require?

The LED current must be less than the maximum permitted for your LED. For standard 5mm diameter LEDs the maximum current is usually 20mA, so 10mA or 15mA are suitable values for many circuits.

## What causes led drivers to fail?

When an LED stops operating before the end of its rated lifetime, it can usually be saved if the driver is replaced. Drivers often fail prematurely due to high internal operating temperatures. Battery-like components called electrolytic capacitors are typically the cause of death.

## Are all LEDs DC?

LEDs are usually considered to be DC devices, operating from a few volts of direct current. … To run an LED-based fixture from a mains supply (e.g. 120 V AC) requires electronics between the supply and the devices themselves to provide a DC voltage (e.g. 12 V DC) capable of driving several LEDs.

## Why do LEDs need constant current?

Constant-Current Drivers LEDs typically have a power-limiting device (either driver or resistors) in order to prevent LEDs from being overdriven. A constant-current driver is used to regulate the amount of current that is supplied to an LED or LED array to maximize LED lifetime.