# Is it OK to use an LED without a resistor?

Is it OK to use an LED without a resistor? Never Ever Connect an LED Without a Resistor, Mostly. When hooking up an LED, you are always supposed to use a current-limiting resistor to protect the LED from the full voltage.

Why do leds need current limiting resistors? In the case of LED strips or commercial lighting, current limiting resistors are installed to minimize the effects of variation in the voltage source. These LED lights often state the voltage that they operate at and that they require constant voltage LED drivers. Get the right power supply for your LED configuration.

Do 12V LEDs need resistors? The LED voltage drop depends on their colour (1.8 – 4.0V), to make them 12V compatible they need a series resistor which is built into ’12V LEDS’.

What happens to an LED if you exceed the maximum current? LEDs are also high-powered. The more voltage you increase, they will create excess heat, which is not favorable. Excess heat makes the LED produce less lights and cut down on its lifetime. Reduced light is closely related to an unfunctional LED system.

## Is it OK to use an LED without a resistor? – Additional Questions

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

You can use any standard household battery, such as a AA, AAA, C or D battery, which are all 1.5V batteries. You could also just hold the wire in place if you don’t have any electrical tape to temporarily connect them. There is no risk of getting electrocuted by such a low voltage.

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

A 12V battery wired to four 3V LEDs would distribute 3V to each of them. The same 12V battery wired to four 3V LEDs in parallel would deliver the full 12V to each of them. A single low voltage power supply can be shared by many LEDs.

### Can a LED be connected directly to a 9V battery?

Yes, a LED can be connected directly to a 9V battery. However, an external resistor is also needed in order to drop the voltage to the five volts required. This is because the forward voltage drop of a LED is usually between 2 and 3V, and the battery voltage is 9V.

### Can high current damage LED?

As discussed previously, if using a 2 A or higher rated current LED type, nothing will happen. However, with a 1.2 A maximum current device, the LED lifetime will be seriously compromised by the constant current power supply.

### What is the maximum current an LED can take?

Most common LED’s require a forward operating voltage of between approximately 1.2 to 3.6 volts with a forward current rating of about 10 to 30 mA, with 12 to 20 mA being the most common range.

### How much current can an LED handle?

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. The current must be in amps (A) for the calculation, to convert from mA to A divide the current in mA by 1000.

### What happens if too much light flows through a LED light?

Your LED draws maybe 20 amps for a few microseconds, turning a very small volume inside it about as hot as the Sun, and then it is all over. If you do this with larger parts, the shrapnel can kill you.

### Why do LED lights explode?

When there is too much electrical or thermal stress, your LED bulb can explode. This can be caused by voltage surges or heat accumulation. LED bulb explosions happen more often with cheap low-quality LEDs.

### Can you damage an LED by reversing polarity?

What damage might it cause? If LEDs are reverse-connected to a sufficiently low voltage supply it is possible that they will simply conduct no current, emit no light and suffer no damage. In such cases correcting the polarity will result in correct LED operation with no adverse effects.

### How big of a resistor do I need for a LED?

LEDs typically require 10 to 20mA, the datasheet for the LED will detail this along with the forward voltage drop. For example an ultra bright blue LED with a 9V battery has a forward voltage of 3.2V and typical current of 20mA. So the resistor needs to be 290 ohms or as close as is available.

### Which leg of an LED is positive?

LED polarity

For an LED to work it needs to be connected to a voltage source with the correct side. The voltage supply side of the diode is the positive (+) side, this is called the anode. The negative side is called the cathode.

### Does it matter which way you wire an LED?

Does it matter which way the LED is connected in the same way that it does when you’re installing a battery? In short, yes, LED bulbs have polarity. They are made with a positive and negative connection. They should be wired into your circuit in the correct direction, or they won’t work.

### Is it better to wire LEDs in series or parallel?

Series, Parallel, or Series/Parallel? The requirements of a lighting application often dictate what type of circuit can be used, but if given the choice, the most efficient way to run high power LEDs is using a series circuit with a constant current LED driver.

### How many LEDs can 5V power?

This is called Kirchhoff’s Voltage Law. So if you have a 5V power supply and each of your LEDs have a forward voltage drop of 2.4V then you can’t power more than two at a time.

### Do LED lights need correct polarity?

Well one of the most common and easiest things to troubleshoot is making sure your LED’s polarity is correct! That’s right, unlike incandescent lighting the polarity of an LED matters– so if it is reversed it will not light up.