Analysis and solution for the cause of low light in the lamps after turning off the lights

LED semiconductor lighting network news In recent years, LED lamps have been rapidly popularized due to energy saving, high brightness and other advantages. Many households use LED luminaires and find that the lights will glow slightly after turning off the lights at night, sometimes rhythmically flashing. This phenomenon occurs with ceiling lamps, downlights, spotlights and light strips. Long-term lighting after turning off the lights will cause damage to the lamps and light decay, reducing the life of the lamps.

The main reason for the illumination after the lamp is turned off is that the lamp is charged after the lamp is turned off. The LED chip is particularly sensitive to current. Even if a wire does not form a current loop, a small amount of light will still be emitted under various complicated sensing states. Specifically, there are the following situations:

1: The switch controls the neutral line, and the live line enters the fixture directly.

This is the most common cause of luminescence. After the opening control of the neutral line, turning off the light only cuts off the power circuit of the luminaire. The fire line is still connected to the luminaire, and the luminaire will be shimmer.

Solution: Re-connect the circuit and let the switch control the live line.

2: Switch with indicator light or electronic switch

Many switches have an indicator light inside. If the indicator light is turned on after the light is turned off, current will flow through the lamp.

Some luminaires use electronic lighting, such as infrared switches, voice-activated lighting, and remote control switches. This type of switch does not completely cut off the circuit. It will also cause the light to illuminate after the lamp is turned off.

Solution: Remove the switch indicator or change the mechanical switch.

3: Double control switch wiring method is wrong

There are many ways to connect the two-control switch. If the electrician adopts the following wiring method, it will turn off the light after turning off the light.

Solution: Follow the zero line to enter the light, and control the fire line to re-wire, as shown below

4: Zero line is charged.

If the above problems are solved, the lamps will still be lit after turning off the lights at night, so it is necessary to consider the neutral line. In theory, as long as the switch is disconnected from the live line, there will be no voltage on the zero line of the lamp, and no induced current will be formed. In real life, zero-line charging is very common. If the neutral line is not well grounded, the line is too long, the wire diameter is thin, or the neutral current is too large, it will cause the zero line to be charged.

Solution: Zero-line electrified individuals are difficult to solve unless the transmission line is modified. Do not touch the conductors, such as walls, roofs, and steel keels, to reduce luminescence. But it cannot be completely solved.

5: There is also a ultimate solution, which is to use the lamp protector. The principle is very simple. It is to directly cut off the connection between the lamp and the power supply through a self-controlled two-way relay, and completely disconnect the neutral line and the live line.

Put the protector inside the fixture, as long as the light is turned off, the output will disconnect the two wires.

Even if the switch is connected incorrectly, the neutral line is charged and will not be transmitted to the luminaire.

Avoid lighting after the lamp is turned off, which can improve the indoor light environment, reduce the light decay of the lamp, and prolong the service life. The price is not very expensive, it is still very good.