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# Capacitor help watch

1. there are a number of capacitors of 2 micro F. each with a max. working potential of 10V.
a. How can you connect them to give a capacitor of 1 micro F and 20 V
b. How can you connect them to give a capacitor of 2 micro F and 20 V

help
2. (Original post by Dynamo123)
there are a number of capacitors of 2 micro F. each with a max. working potential of 10V.
a. How can you connect them to give a capacitor of 1 micro F and 20 V
b. How can you connect them to give a capacitor of 2 micro F and 20 V

help

Do you know the formulas for finding the capacitance of capacitors connected in series and parallel? What do you get with two 2 micro Farad in series, and two 2 microFarad in parallel?

Remember that you add voltages for components in series. This is required to get a 20V connection from 10V capacitors.
It's really just a case of trying a few different combinations of series and parallel.
Have you tried this?

You also need to tell us how many capacitors you have there. Is a number given or can you have as many as you want?
3. Well, I know the formulas and all that stuff, but what is unfathomable is how to connect. They gave us a choice to connect virtually any number of capacitors, which is a bit troubling. I tried with 4 and got around to the capacitance, but couldn't get the voltage. Then I tried with 6 capacitors and again got, like, literally no capacitance corresponding to the one's asked.
4. Think about series and parallel.

What do you get if you have two or more in parallel?
i.e. What does that do to the capacitance?
If they are parallel, why is the voltage rating important? What happens if you exceed it say putting 1000V across the capacitors?

What do you think would happen with two parallel capacitors (capacitance does not matter for this situation) with one rated at 1000v but the other was rated at 10v and then you placed 500v across them. Which capacitor would you be worried about?

Now do the same for series:
What happens to the capacitance?
How does series affect the working voltage?

When you have the answers to those, you can then see what the question is getting at.
5. (Original post by Dynamo123)
Well, I know the formulas and all that stuff, but what is unfathomable is how to connect. They gave us a choice to connect virtually any number of capacitors, which is a bit troubling. I tried with 4 and got around to the capacitance, but couldn't get the voltage. Then I tried with 6 capacitors and again got, like, literally no capacitance corresponding to the one's asked.
As voltages add in series the only way you can do this is to have two 10V capacitances in series to be able to connect.
The very simplest configuration would be to connect two of your 2uF capacitors in series. What would be the total capacitance of these two combined? Does that solve any of the two questions?
6. Well that would solve one of the problems, as the net capacitance would be like 1 micro F.
Gee thanks! That's done! Now I'll try to do the other with probably 3 or 4 capacitors.

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Updated: March 16, 2013
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