I have a tiny inner courtyard that needs a very dim antique light, but not too bright that it shines into the bedrooms.

Finding low-wattage replacement bulbs is a hassle, and I can't imagine ever needing anything bright for this circuit.

Is there any way I can add a resistor to the light switch (or to the light socket itself) to lower the brightness?

  • 4
    You could just install a dimmer...
    – brhans
    Oct 25, 2017 at 13:56
  • Related: electronics.stackexchange.com/q/98279/87782
    – JPhi1618
    Oct 25, 2017 at 14:02
  • 1
    If the light runs off 120 V mains then you could install a fairly low-wattage bulb rated at 240 V. It will be dim and last a long time. Or, those candle-style bulbs might be suitable - they are readily available. Oct 25, 2017 at 15:17
  • 1
    there are all kinds of cheap low-wattage LED bulbs on ebay. not all of them are the best, but for the use prescribed it doesn't much matter.
    – dandavis
    Oct 25, 2017 at 21:29

2 Answers 2


Remember a resistor dissipates heat, if you have a 50 w bulb and want only 25 w of light a resistor would now be heating the area where it is connected also 25 w resistor would be fairly large and more expensive than A dimmer. A dimmer switch would be a safer and more energy efficient way to dim the bulb as the circuitry limits what part of the AC cycle is allowed to pass. So use a dimmer not a resistor.

  • Makes a ton of sense, and I don't want to cause a fire. Thanks for this Oct 25, 2017 at 15:22

Whether it shines into the bedroom is a function of how it's aimed, not how bright it is. Light of any brightness will shine into the bedroom given equivalent fixtures. That's because light is on a decibel scale: reducing lumens from 1600 to 160 only reduces light by 10 decibels.

If you reduce light levels enough to no longer be annoying, now you can't see.

One charm of LEDs is that the light is fairly easy to aim/focus. In fact many consumer screw-in lightbulb replacements have corncob rows of LEDs aiming in every direction, so they act more like traditional bulbs!

We're not a shopping site but shop around and you should be able to find LED-built-in fixtures which look classic, have the yellowish traditional color, and throw the light exactly where you want, and not where you don't.

Once I replaced 3300 watts of mercury vapor lighting (every bit as lumen efficient as LED) with 225W of LED spotlights. The neighbors loved us because we stopped lighting up their bedrooms.

To your question, resistors and placing bulbs in series only works with incandescents, and you should not wire an installation that depends on them, because some goober will replace one with a screw-in LED bulb replacement. Those will treat voltage limiting like a brownout, and defeat your efforts.

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