eli5: How come, when lights are flickering, they sometimes do it really unpredictably?


Seems kind of strange for electronics, which I thought was all 1s and 0s, working or not working type stuff. Like I can’t understand the source of the randomness in such a predictable system as a power source going to a light bulb.

In: 4

Electronics isn’t like all electricity. The power you’re talking about is AC, which is analog, not digital. Also, the path from where the power is generated to your light bulb is usually massive, with transformers in between. Any spotty connection or path change anywhere in that length will cause momentary power loss to your light.

Couple things:

1. Every kind of light bulb I’ve had the pleasure to install at home doesn’t operate on a 1 or 0 basis. They all have non-zero response time when the power cuts off, and emit some light if a dimmer is applied (even if you’re not *supposed* to do this, like some CFLs and LEDs).

2. This is key, because power from the plant isn’t actually continuous. In normal operation it’s not exactly 120V/240V, it’s roughly that value.

If, say, a 14” squirrel were to drop into a transformer in your neighborhood, the quality of electricity you get will vary wildly, depending on the conductivity of the squirrel.

The local grid will only tolerate so much variance before shutting down to protect itself, or the variance resolves. In the meantime, your lights will flicker.