Possibly Weird Fixture Question


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Old 01-14-21, 11:39 AM
K
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Possibly Weird Fixture Question

Hey All. In my upstairs hallway there are two fixtures, both controlled by two switches. I replaced the bulbs and now, when I turn on the light, there is a split second but noticeable delay between when the lights come on. Yes, they are different types of bulbs. The one that lags is an LED and the other is not. Thanks.
 
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Old 01-14-21, 11:56 AM
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That is fairly common. Like bulbs will turn on at the same time.

Have you seen lights on the back of a car come on at different speeds.
That's the difference between incandescent and LED and sometimes between LED bulbs.
 
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Old 01-14-21, 12:15 PM
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I have two separate strings of under cabinet LED's in my kitchen. Each with it's own power supply of a different size. Whenever I turn on the light there is a slight delay and one string always comes on a fraction of a second before the other.

As for cars I mainly notice it on older cars that have a turn indicator on the side mirrors. The indicator on the side mirror is usually LED while tail lights were still incandescent. The LED's on the side mirrors always seem to come on before the blinkers on the back of the car. And, you can notice that the LED's are crisply on and off while the older style lights gradually (though very brief) come up to brightness and fade away by comparison.
 
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Old 01-14-21, 12:21 PM
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Thanks, PJ. I appreciate the response.
 
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Old 01-15-21, 10:41 AM
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I've seen this also with different brands of LED bulbs. There are capacitors in the LED drivers that charge when power is applied. Depending on the design of the drivers and the size of the capacitors, it can take a fraction of a second more or less to get the LEDs power.

 
 

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