Is there a way to power a single light bulb using a generator, and then with the same power source light 10 light bulbs? So basically, can I use say 5V of input to light 10 bulbs, and then use the same input to light a single bulb without blowing it? Assuming all bulbs are the same and at least 2V.
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You can use a 5 V source, and 5 V bulbs, and connect the bulbs in parallel with each other. – The Photon May 10 '18 at 02:25
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Wouldn't you get a drop in luminosity with each additional bulb? – EH10 May 10 '18 at 02:33
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Not if you didn't overload the source. – The Photon May 10 '18 at 02:36
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You should probably read [Choosing power supply, how to get the voltage and current ratings?](https://electronics.stackexchange.com/questions/34745/choosing-power-supply-how-to-get-the-voltage-and-current-ratings) – The Photon May 10 '18 at 02:37
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Can you power 1 bulb with a power source? Yes, it's been done. Can you power 10 bulbs with a power source? Yes, it's been done. That can't possibly be your question. I think you should re-title this with something more specific to where you are confused. – Bort May 10 '18 at 02:43
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I believe you might need to start with **V=I*R**. It seems as if you implied that 10 bulbs might make a bulb blow, but using only 1 bulb makes it less likely. But the adding more bulbs doesn't increase the current in any single bulb. It would either be the same current in each bulb (series), or less (parallel). – Bort May 10 '18 at 02:46
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can you use the same power source that can light a single light bulb to light 10. I would expect to see some sort of drop in luminosity. Otherwise, you could power 10 bulbs just fine but when a single bulb is applied to the circuit, it would likely blow no? – EH10 May 10 '18 at 03:11
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"Wouldn't you get a drop in luminosity with each additional bulb?" In your house do your bulbs get dimmer every time you turn on an additional bulb? – John D May 10 '18 at 05:28
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What if your generator was a raw alternator (just magnets, wire and core) run by a constant external power source? If you think its a stupid concept, ignore it or humor me. – EH10 May 10 '18 at 07:37
2 Answers
Is there a way to power a single light bulb using a generator, and then with the same power source light 10 light bulbs?
My house is powered from the Irish national grid. The power comes from generators. The voltage is maintained closely to 230 V.
I can switch all the lights off, switch one, two or all of them on. The voltage remains at 230 V. If I switch on a large load (cooker or water heater) the voltage will droop a little due to the resistance of the cable between my local transformer and my house but it's only a couple of percent.
So basically, can I use say 5V of input to light 10 bulbs, and then use the same input to light a single bulb without blowing it?
- You need to make sure the bulbs are rated for 5 V.
- You need to make sure that the total current drawn does not exceed the current capacity of the generator or power supply.
Assuming all bulbs are the same and at least 2V.
Bulb voltage must match the supply voltage unless you want to series connect them. You mentioned 5 V supply so you would need to connect 3 x 2 V bulbs in series to make a 6 V string. You could then connect multiple 6 V strings in parallel.

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You can perform both the jobs with the same power source. The only thing that you have to keep in mind is that: 1. The voltage across all the bulbs should be the same (use a parallel connection for this). 2. The current rating for each bulb should not be exceeded otherwise the bulb may blow-up. For this, you can go for a Zener diode (in reverse breakdown region).
If there is something which needs to be kept in mind other than this in your case, just comment and let me know.

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Well I came across this case at uni today (lecturer asked this to see if we could find a solution): If a raw alternator (strictly magnets, wire and core) was attached to a circuit, where the alternator is rotated using a constant external power source, is it possible to add 10 light bulbs in parallel to the circuit and light them? THEN, without changing speed and thus maintaining the same power output, use only a single light bulb in the circuit and light it without popping it? We were working on Inductance, Lenz law and back emf today when he explained this scenario if that helps – EH10 May 10 '18 at 07:23
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Well in that case also, we must remember the law of conservation of energy. So even if you try to use the same source ratings, I personally feel that there should be some energy sink that could help you to use the same for a single light bulb as well (thereby sinking the extra energy to sink as heat or by any other means) – Sumit Panse May 18 '18 at 04:44