Tensión constante frente a corriente constante: ¿Qué tira de LED es mejor para proyectos comerciales?

For commercial lighting projects, if you prioritize long-distance stable power supply, consistent brightness, and longevity, then constant current LED strips are undoubtedly the superior choice. However, if the project budget is limited, the installation distance is short, and there are no stringent requirements for brightness uniformity, then constant voltage LED strips offer better value for money.

Constant voltage and constant current LED strips each have their own advantages: the former has a simple circuit design and lower costs, making it suitable for short-distance decorative lighting; the latter offers stable current and a longer lifespan, making it ideal for large-scale or high-end commercial applications. Understanding the principles and characteristics of these two drive methods can help you make the right decisions in different commercial scenarios.

This article will provide an in-depth analysis of the technical differences, advantages and disadvantages, application scenarios, and selection recommendations for constant current vs. constant voltage LED strips, offering guidance for your commercial lighting projects.

Qué Is A Constant Current LED S¿viaje?

A constant current LED strip is a type of LED strip that maintains a constant current through its LEDs. The current is adjusted and maintained by a continuous current source.

Common constant current LED strips typically incorporate constant current ICs or triode transistors on the strip itself or have built-in constant current chips within the LEDs. Their core feature is precise current control to achieve stable lighting, making them suitable for applications with stringent requirements for brightness and lifespan.

Working Principle 

As shown in the figure below, when a constant current LED strip is in operation, the constant current semiconductor (IC or triode transistor) outputs a constant current of 25mA through its internal integrated circuit, while the voltage automatically adjusts based on the number of series-connected LEDs. If a single LED has a voltage of 3V, three LEDs in series require a voltage of 9V. When the input power voltage is between 10 – 14V, the current remains at the preset value of 25mA, preventing brightness flickering or LED overload.

‌Series-Parallel Circuit Strepidación

As shown in the figure below, the LEDs in the constant current LED strip are designed with a series-parallel configuration. Each group is 50mm apart, with a total of 3 groups. Each group is independently controlled by a constant current triode transistor, ensuring that the current in each group is equal and the brightness of the LEDs in each segment is uniform.

Constant Current LED Strip Technical Advantages

Características	Effects
‌Brightness Consistency‌	No voltage drop or light decay over long distances (>8 meters), with brightness variation <5%
‌Lifespan Guarantee‌	Built-in negative temperature compensation chip, automatic current reduction at high temperatures, light decay ≤10% over 5 years
Safety‌	Overload protection mechanism prevents a single LED failure from causing the entire light strip to malfunction
‌Interference Resistance‌	Current remains stable even with input voltage fluctuations of ±30% (constant voltage solutions with ±10% fluctuations can cause current spikes of up to 50%)

Escenarios de aplicación

• Shopping mall exhibition hall dimming system: Stepless brightness adjustment without flickering; long-distance building contour lighting (such as hotel exteriors, tunnels).

• Precision work environments: Shadow-free lighting in electronics workshops (eliminating flicker interference with production), auxiliary lighting in medical operating rooms.

• High-end homes: Custom cabinet ambient lighting (embedded installation with uniform brightness), indirect ceiling lighting (creating a gradient lighting effect).

• Technical Essence: Constant-current LED strips achieve current closed-loop control through physical chips, differing from the simpler constant-voltage LED strip solution that relies on current-limiting resistors. This is the preferred solution in LED lighting that balances performance and reliability.

Qué Are The Main Types of Constant Current LED Strips?

1. Low-voltage IC-based constant current LED strips

These LED strips typically operate at input voltages of 12V or 24V. Each segment of the strip is designed with transistors or ICs to maintain constant current. By using discrete triode transistors, these strips achieve low-cost constant-current control, making them suitable for simple applications.

IC constant current solutions rely on dedicated driver chips and microcontrollers to achieve high-precision, programmable multi-channel control. LED strips controlled via SPI or DMX512, such as color-changing LED strips, fall under the category of constant-current LED strips and are suitable for commercial-grade smart LED strips.

2. Constant current driver LED rigid strips

Powered directly by a constant current driver, these light strips do not require resistors or transistors for current limiting. They have high luminous efficiency, with input voltages typically set within the range of 22V to 40V.

These LED rigid strips use constant current drivers to provide stable direct current. In principle, the LEDs are connected in series and then paralleled to the main positive and negative terminals, ensuring consistent voltage across each section of the light strip.

These constant current rigid light strips have high power supply compatibility requirements; the total current consumption of the light strip must match the output current of the power supply to achieve optimal LED illumination. These light strips are suitable for custom lengths and short-distance installation environments.

3. High-voltage LED strips

110V/220V high-voltage LED strips typically use constant-current drive technology. The core principle involves converting the AC 110V/220V voltage from the power supply into a DC voltage suitable for LEDs while maintaining a stable current.

Such driver adapters typically feature constant current output functionality. For example, the PM2043 chip is used to drive high-voltage LED light strings powered by mains electricity, achieving multi-segment linear constant current control via harmonic division technology. Suitable for long-distance applications such as architectural profile lighting and outdoor decoration, high-voltage LED light strips require insulation protection during use.

Constant current LED strips offer numerous advantages. Under the same power rating, constant current LED strips provide higher brightness than constant voltage LED strips. Compared to commonly used low-voltage constant voltage LED strips, they experience less voltage drop, ensuring uniform brightness from the beginning to the end of the strip.

What Is A Constant Voltage LED Strip?

A constant voltage LED strip is an LED strip based on constant voltage control, which drives LED chips to emit light by outputting a stable voltage from the power supply. Each group of LEDs is typically connected in series in groups of 3 to 6, based on the required voltage, to achieve constant voltage drive. Constant voltage LED strips are one of the most commonly used types of LED strips, with operating voltages typically set at 12V, 24V, etc.

Their operating principle relies on the stable DC power supplied by a constant-voltage power source. The LED structure is typically designed in parallel or series-parallel configurations, with resistors for current limiting to ensure compatibility with different load requirements under constant voltage conditions. If the power supply output is too high, the LED brightness will be excessively high, shortening the lifespan; conversely, if the output is too low, the brightness will be insufficient, affecting performance.

For example, in a 12V LED strip, each white LED has a voltage of approximately 3V. When three LEDs are connected in series, the total voltage is 9V. Therefore, a 12V power supply is suitable for units composed of three series-connected LEDs, with resistors used for 3V voltage division and current limiting. If higher power is required, multiple such units can be connected in parallel, with the total current being the sum of the currents from each unit.

As shown in the figure below: A small 2835 LED strip light, with each group consisting of 3 LEDs, each group having a voltage of 9V, is compatible with a 12V power supply. A 1-meter-long 12V LED strip contains 120LEDs (40 groups × 3 LEDs), with each group drawing approximately 25mA of current, resulting in a total current of 1A (40 groups × 25mA) and a total power of 12W (12V × 1A).

Constant-voltage LED strips are suitable for applications where brightness and color stability are not critical, such as kitchen cabinet lighting, signage, or decorative lighting, and support basic dimming technology. However, the length of the LED strip is limited (typically no more than 5 meters), and longer lengths may result in voltage drop and uneven brightness at the ends (the brightness difference between the beginning and end can reach 30%-50%).

Compared to constant-current LED strips, constant-voltage LED strips have a fixed output voltage but fluctuating current, resulting in lower installation costs but poorer uniformity; constant-current LED strips maintain a constant current while the voltage varies with the load, enabling longer-distance power supply.

Tensión constante frente a corriente constante: ¿Qué tira de LED es mejor para proyectos comerciales?

Estabilidad

The drawback of constant voltage LED strips is that when the Caídas de voltaje, the current may decrease significantly. When the series length exceeds 5 meters, the brightness of the LED strip at the beginning and end may be inconsistent, with the front section being brighter and the rear section appearing dimmer.

Constant current LED strips maintain a constant current by using dedicated chips or transistors with voltage adaptation; even if the voltage fluctuates within a certain range, the current through each LED remains constant. Therefore, the power remains constant, and the brightness of the front and rear LEDs remains consistent.

The following figure shows the comparison of voltage drop and power test data for our DC 24V constant current and constant voltage LED light strips over distances of 1 to 5 meters:

Type	Classification	1m	2m	3m	4m	5m
CC LED Sviaje	Tensión	23.84V	23.45V	22.83V	22.0V	21.02V
	Potencia	16.08W	31.68W	47.52W	63.12W	80.64W
CV LED Sviaje	Tensión	23.97V	23.64V	23.15V	22.58V	21.96V
	Potencia	16W	31.2W	44.44W	55.92W	65.4W

From the comparison data in the figure above, it can be seen that the voltage of the constant current light strip drops from 24V to 21V after 5 meters, with a power of 80.64W. The average power per meter is calculated to be 16W. The power after 5 meters is very close to that of the first meter, indicating that the power remains constant throughout.

Let’s now look at the data for another constant voltage strip. After 5 meters, the power is 65.4W, with an average power of approximately 13W per meter. It can be seen that as the voltage decreases, the power of the constant voltage strip drops significantly after 5 meters, with a direct decrease of about 20%.

The decrease in power indicates that the current also decreases, causing the LEDs further along to emit less light than those at the front. Therefore, in terms of stability, constant-current LED strips are superior to constant-voltage LED strips.

Seguridad y fiabilidad

In constant-voltage LED strips, even minor voltage fluctuations can cause significant changes in current. If an LED in the circuit shorts out and fails, it can cause the voltage of other LEDs to rise, leading to an increase in current and potentially damaging those LEDs as well.

Constant-current drivers support mixed series and parallel connections, with each series of LEDs receiving independent constant current. If an LED shorts out, the driver chip automatically adjusts the voltage to ensure other LEDs continue functioning normally. Therefore, even if a single LED fails, the remaining LEDs in a constant-current LED strip continue to operate normally.

Vida útil

Constant current drive maintains a constant current through closed-loop control (with an accuracy of ±0.3%), even when the input voltage fluctuates by ±15% or the temperature changes, thereby avoiding issues such as LED overheating, accelerated light decay, or burnout caused by sudden changes in current. Laboratory data shows that the constant current solution can control light decay over 5 years to ≤10%, while the constant voltage solution may halve the lifespan when the voltage fluctuates.

For more information on LED strip light lifespan, read the blog post “Vida útil de la tira de luz LED: ¿cuánto duran y por qué?”

Instalación y mantenimiento

Constant-voltage or constant-current LED strips have a fixed voltage and flexible connection methods, allowing power expansion through parallel connection, suitable for scenarios requiring flexible assembly (e.g., customized LED strip designs). For constant-voltage LED strips installed over long distances (>5 meters) or constant-current LED strips installed over long distances (>8 meters), measures must be taken to mitigate the effects of voltage drop in the circuit. This involves installing power compensation to prevent voltage drop from causing LED brightness reduction and unstable light output.

Additionally, the total power of the light strip and power supply must be strictly matched. If too many units are connected in parallel, the total current may exceed the power supply’s rated current, causing overheating or damage. For example, a 12V power supply with a rated current of 2A can drive a total load current of up to 2A (e.g., 100 groups of 3 LEDs connected in parallel, each group drawing 20mA; exceeding this will cause overload).

Conventional constant-voltage LED strips may see their brightness drop below 70% after three years, while constant-current LED strips maintain a brightness retention rate of ≥95% after three years, with a 70% reduction in light decay. The failure of a single LED does not affect overall operation, eliminating the need to replace the entire section.

Coste

Constant-voltage LED strips are cost-effective, have simple circuits, and can be freely cut to fit curved shapes without the risk of sudden current changes after cutting. Suitable for short-distance (≤5 meters) decorative lighting, constant-current LED strips are relatively more expensive, have a more complex circuit, and have a significantly higher cost compared to constant-voltage strips. Prices vary widely, ranging from $1 (transistor-based constant-current) to $7 (color-changing LED strips). It is recommended to select the appropriate product based on specific requirements (such as brightness stability, installation environment, etc.) and budget.

Commercial Project Selection Decision Table

Key Indicators	Constant Current Solution	Constant Voltage Solution
‌Installation Distance	＞8 meters (uniform brightness)	≤3 meters (voltage drop prevention required)
‌Lifespan Performance	5 years with light decay ≤10%	Voltage fluctuations halve lifespan
‌Cost	30%–50% premium (high long-term return)	Low initial cost (suitable for budget constraints)
Core Risk	Low risk	Current control issues due to voltage fluctuations

The choice of LED strip depends on specific application requirements. SignliteLED offers a variety of related product options, including constant current LED strips and constant voltage LED strips, to meet your diverse needs. Constant current LED strips are more suitable for large-scale applications, while constant voltage LED strips are ideal for cost-sensitive scenarios requiring flexible adjustment of LED quantities.

In commercial lighting projects, constant current LED strip lights are the preferred solution for the majority of scenarios, as they significantly outperform constant voltage solutions in terms of brightness stability, lifespan, and safety. Constant current strip lights are suitable for high-power industrial lighting, long-distance installations, and smart dimming scenarios (such as shopping mall exhibition halls). Constant voltage strip lights have a cost advantage, offer flexible installation, and are suitable for small-scale scenarios.

Cómo Identify Constant Vvoltaje Power Supplies and Constant Current Drivers for LED Sviajes

Constant Vvoltaje Power Supply: The label typically indicates “Output: DC 12V 3A,” “24V 5A,” etc., clearly specifying the voltage and current values. Power = voltage × current (e.g., 12V × 3A = 36W).

As shown in the figure below, this is a constant voltage driver produced by SignliteLED. The label indicates “OUTPUT” as a fixed value of “DC 12V 8.33A” (maximum output current), meaning the current is variable, with a maximum operating current of 8.33A. The power supply’s power rating is 100W.

Constant Current Driver: The label specifies “Output: 300mA 30-100V” or “600mA 40-120V,” etc., with a fixed current value and a voltage range. Power = maximum voltage × current (e.g., 100V × 0.3A = 30W). The driver specifies the output current as a fixed value.

Important Notes for Replacing the Power Supply

The voltage must be strictly matched, and the current can be slightly higher than the original power supply (e.g., if the original power supply is 12V/1A, it can be replaced with 12V/2A), but it must not be lower than the original current; otherwise, it may cause insufficient brightness or flickering of the lighting fixture.

The current value must be matched, and the voltage range must include the total voltage of the original LEDs. For example, if the original fixture uses 30 white LEDs in series (total voltage 90V), select a power supply with the same current and a voltage range that includes 90V (e.g., 600mA 40-120V).

Whether using a constant-voltage mode or a constant-current mode with dynamic voltage adjustment, the core objective is to ensure LEDs operate within safe voltage and current limits.

As a user, simply remember the following key points: check the input/output parameters specified on the product, ensure the driver power supply matches the fixture specifications, and avoid direct wiring or parameter mismatches. By correctly understanding and operating the system, you can fully leverage the energy-efficient advantages of LED lighting while ensuring safe use.

Conclusión

In commercial lighting projects, constant current LED strips have become the preferred choice for the vast majority of medium- to large-scale projects due to their stable current control, excellent brightness consistency, longer lifespan, and higher safety. They are particularly suitable for shopping malls, hotel facades, industrial lighting, and scenarios requiring long-distance wiring.

In contrast, constant voltage LED strip lights excel in terms of simple circuitry, lower costs, and flexible installation, making them more suitable for small spaces, decorative lighting, or budget-sensitive projects.

Therefore, when selecting a solution, you should weigh factors such as project scale, installation distance, budget, and requirements for lighting performance. If long-term stable operation and high-quality light output are priorities, the constant-current solution should be preferred, while constant-voltage solutions are sufficient for small-scale accent lighting.

Additionally, in actual engineering applications, selecting and matching the appropriate driver power supply and strictly adhering to installation standards are essential to fully leverage the advantages of LED strips.

As a professional LED strip lighting supplier, SignliteLED offers a variety of constant current and constant voltage LED strip solutions to help you balance cost control and lighting performance in commercial projects, achieving the best return on investment.

PREGUNTAS FRECUENTES