LEDs are diodes and diodes can only allow electrical current to flow in one direction, therefore LEDs are polarised. The positive pin is the ANODE (+) and the negative pin is the CATHODE (-). It is very important that LEDs are connected to a circuit in the right direction.
LEDs, being diodes, will only allow current to flow in one direction. And when there's no current-flow, there's no light. Luckily, this also means that you can't break an LED by plugging it in backwards. Rather, it just won't work.
LEDs wired in series are connected end to end (the negative electrode of the first LED connects to the positive electrode of the second LED and the negative electrode of the second LED connects to the positive electrode of the third LED and so on and so on...).
LED polarity
This means that LEDs (and other diodes) have positive (+) and negative (-) sides to them. 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.
LEDs are “directional” light sources, which means they emit light in a specific direction, unlike incandescent and CFL, which emit light and heat in all directions. That means LEDs are able to use light and energy more efficiently in a multitude of applications.
Incorrect polarity connection that has caused LED failure will typically result in no light emission and open-circuit LEDs. This could result in signatures ranging from no naked-eye/visible signs of damage to physical damage including signs of burn/overheat.
LEDs are diodes and diodes can only allow electrical current to flow in one direction, therefore LEDs are polarised. The positive pin is the ANODE (+) and the negative pin is the CATHODE (-). It is very important that LEDs are connected to a circuit in the right direction.
By nature, LED lights are polarity-sensitive. If the voltage is of the wrong polarity, it is said to be reverse-biased. Very little current will flow, and the device will not light up. Truck-Lite has developed LED lights that are not polarity-sensitive.
Can LED lights be installed upside down? There is nothing inherent to LED's that require it to be installed in a specific orientation.
The anode (longer lead) is the positive lead and the cathode (shorter lead) is the negative lead.
One of its leads is longer than the other: that's the positive lead, the one that goes to your 5v connection. The shorter wire, the negative lead, goes to ground (Gnd). When you put an LED in a circuit, you need to put a resistor in series with it to limit the current that flows through the LED.
Sometimes it's easiest to just use a multimeter to test for polarity. Turn the multimeter to the diode setting (usually indicated by a diode symbol), and touch each probe to one of the LED terminals. If the LED lights up, the positive probe is touching the anode, and the negative probe is touching the cathode.
Reverse polarity has the potential to cause damage to the internal components of your fixture. Without a fail-safe, the fixture would become hotter than normal operating temperatures and would eventually burn. Some electrical components also have the potential to explode when connected backwards.
Electrical stress damage is often catastrophic for LEDs. Types of electrical stress include Electrical Overstress (EOS), Electrostatic Discharge (ESD), and Reverse Bias. Most LED EOS and ESD failures occur due to thermal damage, metallization damage, contact damage, or junction damage.
Nothing will break. It is like shorting the pins of the LED together. In that case, there is no voltage across it, so it can not be damages.
An LED is a light emitting diode. The LED emits light when it is forward biased and it emits no light when it is reverse biased. The intensity of light is proportional to the square of the current flowing through the device.
We know that LED has two terminals. One is cathode which is connected to the negative terminals of the battery and other is anode connected to the positive terminal of the battery.
If the LED has two leads with leads that are equal in length, you can look at the metal plate inside the LED. The smaller plate indicates the positive (anode) lead; the larger plate belongs to the negative (cathode) lead.
A diode is a device that allows current to flow in only one direction. When a so-called forward bias (a voltage in the "forward" direction) is applied, current flows freely through the device. When the voltage is applied in the opposite direction (called a reverse bias), no current flows.
These LED's will usually have a black, red and white wire. In this case the white is ground(-), red is positive(+) and black is the second positive(+).
But most commonly, LED bulbs may flicker or dim in your home when there are voltage fluctuations in your home's wiring. When electrical loads turn on and off in your home, this creates a change in voltage levels, which may cause the LED lights to occasionally dim or flicker.
There are a number of basic reasons for LED lights to fail but the primary issue is heat. Over-heating can be a result of a number of design and assembly issues but is still the cause of the majority of LED lamp failures – both in the fitting themselves and also the drivers.
The white color refers to cool lighting, while warm lighting is characterized by a softer yellow hue. Correlated Color Temperature (CCT) in different lighting fixtures is used as a description of the color of the light emanating from the light fixture. CCT is measured in kelvins (K) on a 1,000 K to 10,000 K scale.
To avoid voltage drop on longer strips, it is possible to wire a strip from both ends. IMPORTANT: ONLY POWER LED STRIP FROM BOTH ENDS ON THE SAME POWER SUPPLY.