5 Popular Dimming Methods for LED Lights
by Penglight | Date: 21th Sep, 2023
With the gradual development towards intelligent lighting applications, we are no longer confined to the most basic switch On/Off mode. Instead, we are progressively achieving control and adjustment over light. This not only enables energy savings but also allows us to create a desired atmosphere. And, one of the key features that make LED lights so appealing is their ability to be dimmed, allowing users to create the perfect ambiance for any space. In this article, we will explore five of the most popular dimming methods for LED lights. Understanding these methods will help you make informed decisions when it comes to selecting the right dimming solution for your lighting needs. So, let’s dive in and shed some light on these five dimming techniques!
Five Common LED Light Dimming Methods
The commonly used dimming methods can be broadly divided into two main categories:
- Wireless types, such as Zigbee, Bluetooth, WiFi, LoRa, etc.
- Wired types, like DALI, 0/1-10V, Triac, DMX, etc.
Here we will discuss the wired types.
5 Dimming Methods Comparison Chart
1. Dali Dimmable
The DALI standard has defined a DALI network, which includes a maximum of 64 individual units (with independent addresses), 16 groups, and 16 scenes. Different lighting units on the DALI bus can be flexibly grouped to achieve different scene control and management. In practical applications, a typical DALI system can control around 40-50 lamps, divided into 16 groups, while simultaneously processing certain controls/scenes in parallel.
The advantages of DALI lie in its dedicated protocol, which enhances interoperability between different brands, and each DALI device has a unique address code, enabling the individual lamp to be controlled. With bidirectional communication, it is convenient to promptly query and understand device status and information.
Disadvantage: Cost is high and complex commissioning.
2. Triac Dimmable
TRIAC stands for Triode for Alternating Current and is a switch that is used to control power. Triac dimming, also known as Phase-cut dimming, has been used earlier for incandescent lamps and energy-saving lamps, and it is currently the most widely used dimming method for LED dimming.
Triac dimming is a type of dimming based on physical properties. It involves chopping the input voltage waveform starting from phase angle 0, and the voltage is only applied when the thyristor is triggered to conduct. The working principle is to generate an output voltage waveform by cutting the input voltage waveform at a certain phase angle. By applying this principle, the effective value of the output voltage can be reduced, thereby reducing the power of a conventional load (resistive load).
Triac dimmers have advantages such as high adjustment precision, high efficiency, small size, lightweight, and easy for long-distance operation. They dominate the market as a dimming solution. But it has low adaptability and low compatibility.
3. 0/1-10V dimmable
A 0/1-10V dimming device consists of two separate circuits. One circuit is a regular voltage circuit used to turn the power supply to the lighting equipment on or off. The other circuit is a low-voltage circuit that provides a reference voltage to indicate the dimming level of the lighting equipment.
Previously, 0/1-10V dimming controllers were commonly used for fluorescent lamp dimming control. However, now, with power supplies and dedicated control circuits on LED driver modules, 0-10V dimmers can also support a wide range of LED lighting fixtures.
The 1-10V indicates that the dimmer operates within a range of 1-10 volts. When using a resistor dimmer, setting the dimmer to the minimum level of 1V corresponds to an output current of 10% (not a fixed value). Similarly, setting the dimmer to 10V corresponds to an output current of 100%, resulting in maximum brightness.
The 0/1-10V dimmer has a good dimming effect, it has high compatibility, high precision, and cost-effectiveness. However, they require additional signal lines, which make wiring tedious.
4. DMX dimmable
DMX stands for Digital MultipleX, which refers to digital multiplexing technology. DMX512 is a standard protocol for digital communication networks, commonly used to control stage lighting and effects.
Compared to traditional analog dimming systems, a digital lighting system based on the DMX512 control protocol can provide powerful control capabilities for large and medium-sized indoor and outdoor LED lighting systems.
The signal transmission method is RS485 differential signal transmission. Data transmission is based on an 8-bit asynchronous serial protocol with a start bit (low level) and two stop bits (high level), without parity checking. Therefore, each data frame consists of 11 bits, and since each bit has a width of 4 microseconds, it takes 44 microseconds to transmit a single frame. The transmission speed is 250 kilobits per second.
DMX dim system has precise dimming and rich variation effects, but when it comes to wiring, address programming, and commissioning, it’s more complicated.
5. PWM dimmable
Pulse Width Modulation (PWM) technology is used to control analog circuits by controlling the on and off states of the inverter circuit switches. The output waveform of PWM technology consists of a series of equally sized pulses, which are used to replace the desired waveform.
Taking a sine wave as an example, the goal is to make the equivalent voltage of this series of pulses resemble a sine wave, with the output pulses as smooth as possible and with minimal low-order harmonics. Depending on the specific requirements, the width of each pulse can be adjusted to change the output voltage or equivalent output frequency, thereby achieving control over the analog circuit. In short, PWM is a method of encoding analog signal levels with digital signals.
By using a high-resolution counter, the duty cycle of a square wave is modulated to encode the level of a specific analog signal. The PWM signal is still digital because, at any given time, the full-scale DC power is either fully present or completely absent. The voltage or current source is applied to the analog load in the form of a repetitive pulse sequence of on and off states. The on state represents when the DC power is applied to the load, and the off state represents when the power is disconnected.
If the frequency of brightness variation exceeds 100 Hz, the human eye perceives the average brightness rather than the LED flickering. PWM adjusts the brightness by adjusting the ratio of on and off times. Within one PWM cycle, because human perception of brightness in light flickering within frequencies greater than 100 Hz is an accumulative process, the longer the duration of the on state in the entire cycle, the brighter it appears to the human eye.
How to Choose the Right LED Dimmable Power Supply?
After you’ve chosen the dimming method, you need to find the right LED dimmable power supply to support dimming.
To choose the right LED dimmable driver, first, you need to know whether the light fixture is powered by constant voltage or constant current. Normally, you can make judgments based on the parameters indicated on the light fixture. For instance, if the driver marks input voltage DC12V or DC24V, then it’s a constant voltage fixture, you can choose the constant voltage dimmable driver. The most common constant voltage lamps are LED strip lights, wall washers, inground lights, outdoor spotlights, etc.
If the light fixture is marked with input constant current, such as 600mA, and the input voltage is marked in the range of 12-20V, then it’s a constant current light fixture, you can choose the constant current dimmable driver. The popular constant current lights are down lights, spot lights, panel lights, ceiling lights, linear lights, and flood lights.
Secondly, choose the dimmable drivers with sufficient wattage.
For the constant current driver, first, check the power indicated in the light fixture parameters and select a dimmable power supply that corresponds to that power. Next, check the voltage and current of the light fixture. Generally, the voltage range of the dimmable driver is between 9-42V, and the current range is between 120mA-1400mA. The voltage of the selected constant current power supply must cover the required voltage of the light fixture. As for the output current of the constant current power supply, we suggest keeping it within a range of ±5% of the light fixture’s current (if the power supply’s output current exceeds this range, it may affect the lifespan of the light fixture or even cause it to burn out). Some dimmable power supplies are designed with multiple current levels, which allow you to set the corresponding current level using the dip switches.
As for the constant voltage driver, you need to determine first whether the input of the light fixture is 12V or 24V. Then, select a dimmable power supply with the corresponding output voltage. Secondly, choose a dimmable power supply based on the power of the light fixture. As a general recommendation, the power of the constant voltage dimmable power supply multiplied by 0.8 should be greater than or equal to the power of the light fixture. The power margin is left to prevent damage to the power supply due to increased power caused by heat generated by the light fixture during prolonged use.
What are some Common Applications for Dimmable LED Lights?
Dimmable LED lights find applications in various settings and scenarios. Some common applications include:
Residential Lighting: Dimmable LED lights are widely used in homes for creating different lighting moods and adjusting brightness levels in living rooms, bedrooms, and dining areas. They allow homeowners to set the desired ambiance for different activities, such as relaxing, entertaining, or reading.
Commercial Spaces: Dimmable lighting is frequently employed in commercial settings like offices, conference rooms, and lobbies. They provide flexibility in lighting levels, enabling users to customize the brightness to suit specific tasks, enhance productivity, and create a comfortable working environment.
Hospitality Industry: In hotels, restaurants, bars, banquet halls, and lounges, especially in the public areas of the hotel, LED lights with dimmable functions are extensively used to create the desired atmosphere for guests. Whether it’s a cozy and intimate setting or a vibrant and energetic ambiance, dimming allows for dynamic lighting control to match the mood of the establishment.
Retail Stores: Dimmable light fixtures are utilized in retail environments to highlight products, create visual interest, and set the right mood for shoppers. The ability to adjust lighting levels helps showcase merchandise effectively and create an inviting shopping experience.
Art Galleries and Museums: In art galleries and museums, precise lighting control is crucial for accentuating artwork and artifacts. Dimmable lamps offer the ability to adjust brightness and color temperatures, ensuring proper illumination while preserving the integrity and longevity of delicate exhibits.
Theatrical and Entertainment Lighting: LED dimmable lights play a vital role in stage performances, concerts, theaters, and other entertainment venues. They allow lighting designers to create dramatic effects, smoothly transition between scenes, and control the intensity and color of the lighting to enhance the overall experience.
What are the Advantages of using Dimmable Lighting compared to Traditional Incandescent or Fluorescent Lights?
Using dimmable lights offers several advantages over traditional incandescent or fluorescent lights:
- Energy Efficiency
Dimmable lights are highly energy-efficient. They consume significantly less electricity compared to incandescent or fluorescent lights, resulting in lower energy bills and reduced carbon footprint. LED lights convert a higher percentage of energy into light rather than heat, making them more efficient and environmentally friendly.
- Longer Lifespan
LED lights have an exceptionally long lifespan compared to traditional lights. Nowadays, the life span of LEDs can be more than 50,000 hours, they can last up to 25 times longer than incandescent bulbs and significantly longer than fluorescent lights. This longevity reduces maintenance and replacement costs, especially in commercial and industrial settings.
- Instant On/Off
LED dimmable lights offer instant illumination when turned on, unlike some fluorescent lights that may require warm-up time. They also provide immediate response to dimming commands, allowing for quick adjustments to the desired brightness level.
- Dimming Flexibility
LED lights provide smooth and precise dimming capabilities. They can be dimmed to various levels without affecting their color temperature or light quality. This flexibility allows users to create different lighting atmospheres, adjust brightness according to specific needs, and enhance visual comfort.
- Design and Aesthetic Options
LED lights come in various shapes, sizes, and designs, providing a wide range of options to suit different lighting requirements and interior aesthetics. They can be integrated into fixtures, recessed lighting, strip lights, and decorative luminaires, allowing for creative and customized lighting designs.
- Durability and Safety
LED lights are highly durable and resistant to shock, vibrations, and temperature fluctuations. Unlike incandescent bulbs, they do not contain fragile filaments or glass components. Additionally, LED lights emit very little heat, reducing the risk of burns or fire hazards.
- Environmental Benefits
Dimmable LED lights are free from hazardous substances such as mercury, which is commonly found in fluorescent lights. LED lights are also recyclable, contributing to reduced electronic waste and supporting sustainable practices.
Are there any Specific Considerations or Requirements for Installing Dimmable LED Lights in Different Settings?
Yes, there are specific considerations and requirements for installing dimmable LED lights in different settings. Here are some key factors to keep in mind:
- Dimmer Compatibility
Not all LED lights are compatible with all dimmer switches. It is essential to ensure that the dimmer switch you choose is compatible with the specific dimmable LED lights you plan to install. LED manufacturers usually provide a list of recommended dimmer switches or compatibility information for their products. Using an incompatible dimmer can result in flickering, buzzing, or improper dimming performance.
- Load Capacity
Dimmer switches have a load capacity rating that indicates the maximum wattage they can handle. It is crucial to calculate the total wattage of the LED lights you intend to connect to a dimmer switch and ensure that it falls within the load capacity of the dimmer. Exceeding the load capacity can cause the dimmer switch to overheat or malfunction.
Proper wiring is essential for dimmable LED lights. We recommend consulting a qualified electrician to ensure correct wiring connections and compliance with electrical codes and safety standards. Improper wiring can lead to performance issues, electrical hazards, or damage to the dimmer switch or LED lights. Penglight can also help you with the installation by offering guidance and drawing.
- Dimming Range and Smoothness
Different dimmable LED lights and dimmer switches may offer varying dimming ranges and smoothness of dimming. Consider the desired dimming range and the level of smoothness required for your specific application. Some dimmable LED lights may dim to very low levels, while others may have a limited dimming range. Similarly, certain dimmer switches provide smoother dimming performance compared to others.
- Lighting Control Systems
In larger installations or commercial settings, consider integrating dimmable LED lights into a lighting control system. These systems offer advanced features such as centralized control, scheduling, and automation. Ensure that the dimmable LED lights you choose are compatible with the lighting control system being used.
- Application-Specific Requirements
Different settings may have specific lighting requirements. For example, in healthcare facilities or educational institutions, dimmable LED lights may need to meet certain standards for color rendering, flicker-free performance, or compatibility with emergency lighting systems. Always consider any specific requirements or regulations applicable to your particular installation.
- Trialing and Testing
In some cases, it may be necessary to trial and test the dimmer switch with the LED lights before committing to a full installation. Purchase a sample dimmer switch and a few LED lights of the same model you plan to install. Connect them and observe the dimming performance. Look for any flickering, buzzing, or compatibility issues. This method allows you to see firsthand if the dimmer switch and LED lights work well together.
Remember, compatibility can be influenced by factors such as the type of LED driver used in the light fixture, the dimming method employed, and the electrical load of the system. It’s crucial to consider all these factors and ensure compatibility between the dimmer switch and the specific LED lights to achieve optimal dimming performance and avoid compatibility issues.
What are some Common Issues that can Occur if the Dimmer Switch is not Compatible with the LED lights?
If the dimmer switch is not compatible with the LED lights, several issues can occur, including:
Flickering: Incompatible dimmer switches can cause LED lights to flicker or shimmer, even when set at a specific dimming level. The flickering can be distracting and irritating, affecting the overall lighting quality and user experience.
Limited Dimming Range: LED lights may have a reduced dimming range or limited control when used with incompatible dimmer switches. The lights might not dim to the desired lower levels or may abruptly turn off before reaching the lowest dimming setting.
Buzzing or Humming Noises: Incompatibility between the dimmer switch and LED lights can result in buzzing or humming noises. This noise can be an annoyance and can indicate an issue with the dimming system.
Inconsistent Performance: LED lights may exhibit inconsistent or erratic dimming performance when operated with incompatible dimmer switches. The lights may not respond consistently to dimming adjustments or may exhibit uneven dimming across multiple fixtures.
Overheating: In extreme cases, an incompatible dimmer switch can cause LED lights to overheat. This can lead to premature failure of the LED lights, reduced lifespan, or even pose a fire hazard.
Damaged Dimmer Switch: Incompatibility between the LED lights and the dimmer switch can also damage the dimmer switch itself. Exceeding the load capacity or using incompatible wiring connections can cause the dimmer switch to malfunction or fail.
To avoid these issues, it is crucial to ensure dimmer compatibility with the specific LED lights being used. Check the product specifications and compatibility lists to select a dimmer switch that is expressly designed for use with LED lights. Additionally, consulting with a qualified electrician or lighting professional such as Penglight can help ensure a compatible and optimal dimming system installation.
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