Doesn't Alternating current cause fatigue?

In summary: The main difference between flicker and alternating current is that AC causes a "flicker" due to the way it oscillates, while DC does not.
  • #1
rohanprabhu
414
2
Take the case of a lamp bulb. When applied an Alternating current across it.. it basically goes on and off 50 times in a second [in India atleast.. we get 50Hz]. Now, it means that the filament gets hold and cold continuously. From wikipedia:

fatigue is the progressive and localised structural damage that occurs when a material is subjected to cyclic loading.

so.. is alternating current more damaging for appliances as compared to DC? Almost all electronic devices convert AC to DC.. so they are out of the question... I'm thinking about the rest of the simple devices.. like light bulbs and stuff.
 
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  • #2
Do think that the temperature of the filament has time to change much during each current cycle?
 
  • #3
Doc Al said:
Do think that the temperature of the filament has time to change much during each current cycle?

so.. you basically mean to say that the temperature of the filament remains more or less constant?
 
  • #4
rohanprabhu said:
so.. you basically mean to say that the temperature of the filament remains more or less constant?
I haven't studied the matter, but that's what I would expect. (Where are all the light bulb engineers when you need them?) I would expect most thermal fatigue to occur when you first turn on the bulb.
 
  • #5
Doc Al said:
I would expect most thermal fatigue to occur when you first turn on the bulb.

That's what I was taught, and empirical evidence seems to support it. I have absolutely never in my life seen a light bulb blow out except when first turned on. That's the same reason that I never shut my computer off; supposedly the thermal expansion/contraction is the main failure point for the internal circuitry. (The HD and screen go to sleep on their own, so I'm not sure that there's any benefit from their perspective.)
 
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  • #6
Well, think about common flicker. We all see it in flourescent bulbs, yet we don't see it in incandescent bulbs.
 

1. What is alternating current and how does it work?

Alternating current (AC) is an electrical current that periodically reverses direction. This means that the flow of electricity alternates between positive and negative directions, typically at a frequency of 50 or 60 cycles per second. AC is used to power most household appliances and is generated by power plants, which convert mechanical energy into electrical energy.

2. Why is alternating current used instead of direct current?

Alternating current is used because it has several advantages over direct current (DC). AC can be easily converted to different voltages using transformers, making it more efficient for long-distance transmission. Additionally, AC can be easily converted to different frequencies, allowing it to power a wider range of devices. Finally, AC is safer to use, as it can be more easily controlled and does not build up charge in the body like DC can.

3. Can exposure to alternating current cause fatigue?

No, exposure to alternating current does not directly cause fatigue. Fatigue can be caused by a variety of factors, but there is no evidence to suggest that AC is one of them. However, prolonged exposure to electrical devices can indirectly contribute to fatigue if they are emitting harmful levels of electromagnetic radiation or if they are causing disruptions in sleep patterns.

4. Are there any health risks associated with alternating current?

No, alternating current is generally considered safe for human use. However, if the voltage is too high or if there is faulty wiring, it can pose a risk of electric shock. Additionally, prolonged exposure to high levels of electromagnetic radiation from electrical devices can potentially have negative health effects, but this is not directly related to the use of AC.

5. Can alternating current affect the quality of sleep?

There is no scientific evidence to suggest that alternating current can directly affect the quality of sleep. However, as mentioned earlier, prolonged exposure to electrical devices can indirectly impact sleep patterns. It is recommended to limit exposure to electronic devices before bedtime to promote better sleep.

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