ProblemSolution - Voltage Fluctuations

PROBLEM: Varying LED indicator performance due to voltage fluctuations

LED indicators are widely used in various applications such as commercial- and industrial electronics, transportation, aviation, and communication. They are known for their low power consumption, long lifespan, and high efficiency.


However, one of the challenges of using LED indicators is voltage fluctuation. This problem can affect the brightness and accuracy of an LED indicator and can lead to confusion and errors when trying to read the status of a given system.

Here we'll discuss:

• Causes of voltage fluctuation.

• How voltage fluctuation affects LED indicators.

• LED indicator solutions that are suitable for
  fluctuating voltage operation.

• Other benefits of these LED indicators.  


Causes of voltage fluctuations that affect LED indicators:

1. Power supply fluctuations: The power supply that provides electricity to the LED indicators can fluctuate due to a variety of reasons, including voltage spikes, power surges, and brownouts.

2. Electrical noise: Electrical noise from other devices or appliances can cause voltage fluctuations in the power supply, which can affect the indicator performance.

3. Wiring issues: Poor wiring or wiring that is not properly grounded can cause voltage fluctuations in the LED.


Voltage fluctuations can significantly affect LED indicators in many ways, including their function as a system status signal and their ultimate lifespan.

Brightness variation: LED indicators are sensitive to changes in voltage, and fluctuations in voltage can cause the brightness of the LED to vary. This varying brightness in LED indicators can make it difficult to read and interpret the information being displayed. If the brightness varies too much, it can be distracting and cause confusion.

Shortened Life: Voltage fluctuations can drastically shorten the life of LED indicators. If the voltage is too high or too low, it can cause excessive heat to build up within the LED, which can damage the internal components and reduce the lifespan of the LED.


Constant-intensity LED indicators are the solution to these problems. 

Constant-intensity LED indicators are a type of LED indicator that maintains a consistent level of brightness regardless of changes in voltage or temperature. They typically use a voltage regulator or current limiting circuit to ensure that the LED remains at a constant brightness level, even if the input voltage or temperature fluctuates. This makes them a popular choice for applications where accuracy and consistency are important. 

An example of such LED indicators are Dialight’s 556 Series Constant Intensity 1” Panel Mount Indicators. These rugged and watertight indicators are available in standard and daylight-viewable versions and operate across a voltage range of 18 -48V DC. 


Constant-intensity LED indicators come with numerous benefits:

1. Consistent brightness: LEDs driven with a constant current source provide consistent brightness regardless of changes in voltage or temperature, ensuring that the LED's light output remains constant and predictable. This ensures that the indicator is always easy to read and provides accurate information.

2. Longer lifespan: LEDs are sensitive to changes in current, and driving them with a constant current source can help prevent overdriving, which can cause the LED to heat up and reduce its lifespan. Since constant-intensity LED indicators are designed to maintain a constant current and a  consistent brightness level, they are less likely to fail prematurely and can last longer.

3. Energy efficiency: Constant-intensity LED indicators consume less power than their standard counterparts. Driving LEDs with a constant current source ensures that the LED operates at its optimal efficiency, maximizing its light output per unit of power consumed.

4. Precise control: A constant current source allows for precise control over the LED's brightness, enabling it to be dimmed or brightened as needed for different applications.

5. Simplified circuit design: Using a constant current source can simplify circuit design by eliminating the need for current-limiting resistors and reducing component count and cost. 

6. Versatility for manufacturers: Since constant intensity LED indicators offer a seamless performance across a range of voltages, they are an ideal choice for manufacturers that sell products in multiple voltage versions. Here, instead of stocking and storing multiple LED indicators with different operating voltages, manufacturers only need to source one constant-intensity LED indicator—regardless of the system’s operating voltage.

7. Reliable indication during emergencies: The benefit of using constant intensity LED indicators on a system with a battery backup is that they provide a reliable and consistent visual indication of the system's status even during power outages. Since these LED indicators maintain a constant level of brightness they continue to operate even when the input voltage from the battery backup is lower or not stable.


Overall, driving LEDs with a constant current source can result in a more reliable, efficient, and predictable performance. This explains why constant-intensity LED indicators are a favored choice among manufacturers of electronic devices and industrial equipment requiring high levels of accuracy, consistency, and reliability.

A Dialight LED expert can help you find the most efficient and best-performing LED indicator for your application. Contact us today so we can discuss solutions that offer maximum performance at competitive pricing.