Can I use an inline resistor to achieve differential dimming?

I installed three 14-volt LED strips wired in parallel to a dimmable power supply. One strip is about 65 inches long and mounted under our kitchen cabinets for task lighting. The other two 31-inch strips are mounted in the cabinets above that have glass doors. These are strictly decorative, and my wife would like them to be dimmer than the undercabinet light. Can I use an inline resistor to dim the upper two strips?

While we completely understand the idea behind using an inline resistor to achieve the goal of differential dimming, unfortunately, this would not be a practical and recommended approach.

The primary concern is that an inline resistor would need to dissipate a significant amount of heat. If, for example, you have 5 feet of LED strip connected, this would amount to nearly 30 watts (5.5 watts per foot). Reducing the power to the system by just 10% using a resistor would require dissipating 3 watts, which is a significant amount of heat for a small, passive component such as an inline resistor.

There are also concerns with heat buildup and potential safety concerns, especially in a residential installation.

We realize this will increase the total component cost for your project, but the best solution would be to utilize two separate power supplies connected to two separate wall-dimmers.

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LED strip lightsLED dimmers

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