Capacitor value -- series/parallel caps to increase voltage

In summary, to obtain a capacitor value of 1.5 uF rated for 1600 V, you will need 12 2 uF, 400 V capacitors. This can be achieved by connecting four capacitors in series to increase the working voltage to 1600 V, and then connecting three strings of four capacitors in parallel to achieve a total capacitance of 1.5 uF. If the target rating was 1500 V, the same procedure would still require 12 capacitors with an actual rating of 1600 V. However, in practice, there are other factors to consider such as capacitor tolerance.
  • #1
anand raj
17
0

Homework Statement


The number of 2 uF, 400 V capacitors is needed to obtain a capacitor value of 1.5 uF rated for 1600 V is.....


Homework Equations




The Attempt at a Solution



equating the energy on both sides,
1/2*2*400^2*n=1/2*1.5*1600*1600,
n=12, here n = number of capacitors
[tell me my procedure is right or not,and how]
 
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  • #2
12 is the right answer.
 
  • #3
Suppose the problem was slightly different eg...

The number of 2 uF, 400 V capacitors is needed to obtain a capacitor value of 1.5 uF rated for 1500 V.

Your approach would give..
1/2*2*4002*n=1/2*1.5*15002
and that gives n=10.5

Rounding up to 11 doesn't work.

Going back to the original problem (1600V)...

To increase the working voltage you have to add caps in series. Four caps in series increases the working voltage from 400 to 1600V but at the same time the capacitance of a string of four reduces from 2uF to 0.5uF. So you need three strings in parallel to make 1.5uF. Three strings of four make 12.

If the target rating was 1500V you would still need 12 capacitors. The actual rating would be 1600V but you can use it at 1500V.

PS In practice it's not wise to do this. You need to factor in things like the capacitor tolerance which might mean the voltage isn't shared equally... and there are other issues.
 
Last edited:

Related to Capacitor value -- series/parallel caps to increase voltage

1. What is a capacitor and how does it work?

A capacitor is an electrical component that is used to store and release electrical energy. It consists of two conductive plates separated by an insulating material known as a dielectric. When a voltage is applied to the plates, one plate becomes positively charged and the other becomes negatively charged. This creates an electric field between the plates, allowing the capacitor to store energy.

2. How do series and parallel capacitors differ?

In a series circuit, capacitors are connected one after the other, with the positive plate of one capacitor connected to the negative plate of the next capacitor. This increases the total capacitance of the circuit, but the voltage remains the same. In a parallel circuit, capacitors are connected side by side, with the positive plates connected together and the negative plates connected together. This increases the total voltage of the circuit, but the capacitance remains the same.

3. How can I use series capacitors to increase voltage?

To increase voltage using series capacitors, you would connect multiple capacitors in a series circuit. The total voltage of the circuit would be the sum of the individual capacitor voltages. For example, if you have two 10V capacitors connected in series, the total voltage would be 20V.

4. How can I use parallel capacitors to increase voltage?

To increase voltage using parallel capacitors, you would connect multiple capacitors in a parallel circuit. The total voltage of the circuit would remain the same, but the total capacitance would increase. For example, if you have two 10V capacitors connected in parallel, the total capacitance would be double that of a single 10V capacitor.

5. What is the maximum voltage I can achieve by using series/parallel capacitors?

The maximum voltage that can be achieved by using series/parallel capacitors depends on the individual capacitor values and the number of capacitors used. It is important to note that capacitors have a maximum voltage rating, so it is important to choose capacitors with a high enough rating to handle the desired voltage. It is always recommended to consult a professional or use a voltage calculator to determine the maximum voltage that can be achieved with series/parallel capacitors.

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