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How to Connect a Single LED Element to the AC Network

Jul. 03, 2020

Compared with traditional lighting, connecting LEDs to the grid is a whole new world. The LED needs direct current (DC) to light up, and the alternating current (AC) will not work. AC modules are also available, but these modules are not included here.

In this article, commercial lighting Cob chip suppliers will focus on connecting a single COB LED.

LED driver

You need an LED driver, which is actually an AC/DC converter. It converts the AC voltage/current of the power grid into the appropriate DC voltage/current required by the LED element. You can find the LED requirements from the datasheet provided by the manufacturer.

Connect COB LED to AC network

In the case of COB, you must create a closed circuit so that current can flow through the LED element. COB LED is basically a diode, in its electrical nature: current can only flow in forwarding mode. This means that you must connect the positive (+) pad of the COB LED to the positive terminal of the LED driver. In the same way, you connect the negative (-) pad of the COB LED to the negative terminal of the LED driver. See the Figure below.


In this way, you can create a closed circuit that requires current to pass through the LED so that the LED will emit light. This closed-circuit formed by the LED driver and the COB LED is called the secondary side of the LED driver. The LED driver inputs power and current into a closed circuit to pass the COB LED on the secondary side.

On the primary side, the LED driver obtains power from the power grid and the AC network. The terminals of the primary LED driver are called the line and neutral. They are connected to the line of the AC network and the neutral point connection. If you have an LED driver with a cable, they are usually blue (neutral) and brown (wire). Some drivers also have a ground terminal, usually connected to the lamp body with a ground wire. However, the primary side also needs to close the circuit; between the network and the driver.

Usually, you need to use some kind of wiring board to connect the drive to the grid on the primary side.


Two options

Finally, for physically connecting the COB LED to the LED driver, you have two methods:

Solder the wires on the solder pads of the COB

Use solderless connectors.

In the first method, you use a high-temperature soldering iron to manually solder the wire. This soldering iron will melt soldering materials such as tin. After cooling, there is a joint between the wire and the COB pad. You need two wires, one for the positive pad and one for the negative pad.

In the second method, solderless connectors are used.

The role of solderless connectors is the same as soldered wires. In this method, you also need electrical connections, but you do not need to solder the wires with molten tin. You simply push the wire into the push-in terminal of the connector. Similarly, positive to positive, negative to negative. There is a mark on the connector. Basically, these push-in terminals work in combination with metal plates and springs and then connect to the solder pad of the COB LED.

The difference between these methods is that, unlike soldered joints, in the solderless connector method, the spring may loosen over time, and contact loss may occur. Solderless connectors are generally considered more expensive than manual soldering.