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What is the use of a circuit board for LED lamps?

The LED lamps on the Aluminum base board quickly entered thousands of households with their advantages of high brightness and energy saving. In the process of using 1 layer LED Based Night Lamp, I found that there is a small circuit board on the Aluminum 2.0W LED board. What is the function of this board on the LED lamp? The following is an analysis for everyone.
The characteristics of LED lights are more sensitive, and it also has negative temperature characteristics. It has relatively high requirements for use conditions, and devices need to be added to stabilize and protect it during use. This produces the LED driver, and the circuit board we see is the constant current driver of the LED. Some relatively inexpensive lamps (such as some spherical LED lights on the Internet and on the roadside stalls) use a RC step-down drive, but now there are not many of them. Here we take a constant current drive as an example.

The role of this PCBA
1. Provide a stable and reliable output voltage, and can adjust the output current according to the size of the load, so as to protect the lamp from burning due to high current.
2. To prevent the damage to the LED caused by lightning and surge voltage, and the grid voltage is not always stable, constant current drive can provide protection against overvoltage and overcurrent.
3. Adjust the brightness of each lamp bead so that the overall brightness is the same.
4. LED lamp is different from the incandescent lamp that we have used all the time. It can not be directly added to AC 220 voltage. Its working voltage is DC 2-3V. And this constant current drive can convert the AC220V voltage in the home power supply circuit into the DC DC voltage required by the LED lamps.
How to repair common failures of LED lights
1. When the switch is not turned on, the lamp flashes by itself
In daily life, you can sometimes find that when the switch is open, the lamps will flash at intervals.
Solution:
This kind of problem is generally because during the installation process, the switch of the lamp is connected to the zero line, which causes the problem that the switch is still flickering when the switch is not turned on. The correct connection method is to connect the switch to the live wire, so that it is safer during daily maintenance.
▲Correct switch connection
Another reason:
There is an electrolytic capacitor inside the constant current drive for filtering. When there is a weak current in the circuit, this capacitor can store electric charge. When it reaches a certain level, it will be released, which shows that the lamp flickers. In addition, the installation of lamps and lanterns is more complicated, and self-inducted current is generated, which will also cause it to flicker.
How to distinguish the zero line of fire:
Find an electric pen, the index finger of your finger is against the cap end of the electric pen, the thumb, middle finger, and ring finger gently pinch the electric pen to keep it stable, and the tip of the electric pen touches the wire.
According to the wire color:
The color of the live wire (L) must be red, yellow, and green, the color of the neutral wire (N) must be black and blue, and the color of the ground wire (PE) must be yellow and green. Face the 3-hole socket, zero on the left, fire on the right, and ground wire in the middle.
2. The lamps are not bright
LED lamps basically use all the lamp beads to be connected in series. According to the law of the series circuit, once a lamp bead is damaged, all the lamp beads will not emit light.
We can observe each lamp bead on the Aluminum LED board. If there is a black spot in the middle of some lamp bead, it means that the lamp bead has been damaged. If you have a multimeter in your home, you can use the multimeter to test the lamp beads one by one, which is more accurate.
▲There is a black dot inside
If only individual lamp beads are damaged, we only need to short-circuit it with a wire. If there are lamp beads of this type at home (this kind of lamp beads are generally very cheap, only ten dollars Can buy a pack) can also be replaced with the same model of lamp beads. If a lot of lamp beads are damaged, they cannot be short-circuited, and a new lamp panel needs to be replaced by purchasing a lamp panel of the same model.
3. All lamp beads are normal, and the driver is damaged
The probability of this happening is generally not very high, but it will happen. At this time, we only need to buy a new one according to the original driver model, and pay attention to whether the output voltage of the driver is the same as the original driver.
▲Different output interfaces
At the same time, we must pay attention to another issue, that is, the type of output interface of the driver. The plugs for different lamps are generally different, and you need to purchase them according to your own lamp plug type, which is generally the one at the top left of the above picture.
Precautions
No matter which operation you perform, you need to cut off the power before proceeding. Safety first. At the same time, please pay attention to when purchasing a driver. If your lamps are used in a relatively humid place, you can choose a driver with waterproof function, which is not only safer, but also prolongs the service life.