A DIN WHEN DIMMING
Q: I just purchased an 18ft roll of amber/white flexible LEDs to light up our cabin down below. They are plenty bright for reading charts, and a rotary dimmer pulls them down to a wonderful warm glow for dining. The one down side is that when I dim the light strip, a terrible racket comes over my audio system and wipes out my morning SSB weather net reception. I didn’t think LEDs gave off noise.
Don Arnold, Cardiff-by-the-Sea, CA
GORDON WEST REPLIES
You are correct. LEDs run cold and silent. The noise you hear is coming from the pulse-width modulated dimmer network. Run the LEDs full on with no dimming or full off, and there should be no noise. During dimming, however, the dimmer circuit can make a horrible racket over audio systems, as well as your marine SSB. Therefore, short of series resistors on a switch, your new string of dimmed LEDs will indeed create radio racket.
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March 2016
