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Voltage Drop: Why It Still Matters for LED Light Bulbs

Updated: Jun 13, 2023

With the rise of LED (Light Emitting Diode) light bulbs, one might assume that voltage drop is no longer a concern.

However, that assumption would be incorrect. While LED bulbs are known for their energy efficiency and longevity, they still require the proper voltage to function optimally.

This means that voltage drop remains an important consideration, especially when dealing with long distances between the power source and the bulb.

To understand why voltage drop matters, let's delve into the basics. LED bulbs, like any other electrical device, require a specific amount of current to emit light effectively.

The wattage of the bulb determines this current requirement. When the distance between the power source and the bulb is substantial, adjustments must be made to either the size of the conductor or the voltage across the conductor to compensate for the potential voltage drop.

To calculate the voltage drop in a 12v system, you can use the following formula:

Voltage Drop = (Distance of Conductor × Total Wattage on Conductor) / Cable Constant (based on conductor size) × 2

In a 12v system, the transformer plays a crucial role. It steps down the voltage from the existing power source, typically 120v, by a factor of 10.

Ideally, if the power source is 120v, the transformer should supply a minimum of 12v. However, if the power source deviates from the expected voltage, the transformer may provide less than 12v or more than 12v.

LED light bulbs require a voltage range of 8v-15v to operate properly. Therefore, it is prudent to install a multi-voltage/multi-tap transformer in situations where the loads are high in wattage or located far from the power source. This type of transformer can accommodate varying voltage requirements and ensure that the LED bulbs receive the appropriate voltage for optimal performance.

By addressing voltage drop concerns and selecting the right transformer, you can overcome potential issues that may arise when powering LED light bulbs over long distances.

Ensuring that the LED bulbs receive the correct voltage range will help to maintain their longevity, energy efficiency, and desired level of illumination.

Voltage drop remains a relevant consideration even in the era of LED light bulbs. While LEDs offer numerous benefits, including energy efficiency, they still rely on receiving the proper voltage for optimal performance.

By understanding the impact of voltage drop and employing appropriate measures such as adjusting conductor size or using a multi-voltage/multi-tap transformer, you can ensure that your LED lighting system operates at its best, regardless of the distance from the power source.


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