The Series And Parallel Capacitors Formula To Calculate The Right Capacitances
The series and parallel combination of capacitors is important in the electronic repair line. Not every capacitor value you can
find from the electronic suppliers thus you have to use the series and parallel capacitor formula to calculate your desire capacitor
value and voltage rating for replacement. It is quite simple to find a replacemnt with the formula given below
Capacitor In Series
If two or more capacitors are connected in series as shown above, the total capacitance is less than that of the smallest
capacitor in the group.The value of the total capacitance C can be calculated by the formula below. The results is exactly the same as the
resistances in parallel. If the capacitors of 1 microfarad each are connected in series, the net capacitance value offered by the
combination of the two capacitors is: -
So the net value is just half of an individual capacitor. Capacitors are used in series to provide a higher voltage breakdown
rating for the combination. In many circuits,high value resistors are connected in parallel with all capacitors to ensure that the
voltage is distributed equally. These resistors should have enough wattage rating to dissipate heat generated by the flow of current
through them.
When electrolytic capacitors are to be connected in series, connect the positive side of the capacitor to negative exactly as when
you are connecting batteries in series. (Fig. 1)
In series capacitors, the working voltage of each capacitor is sum up. This series connection decreased the capacitance but an
increase in working voltage.
The total value of this combination is: -
but the working voltage becomes 700 volt.
Capacitors in Parallel
When a number of capacitors are connected in parallel as shown below, the total or effective capacitance of the group is equal to
the sum of the individual capacitancesThe equation for calculating the total capacitance C obtained by capacitances C1, C2 C3 etc.The
formula for parallel capacitor is same as the resistance in series.
If 5, 10 and 15 microfarad capacitors are connected in parallel as shown below, the combination would provide a total value
capacitance of 30 microfarad. This type of connection is used to get higher capacitances. The voltage rating of each capacitor should be
sufficient to withstand the voltage that will be applied to them in practical circuits.
When electrolytic capacitors are connected in parallel, make sure the capacitor polarity connect from positive to positive and
negative to negative otherwise the capacitor may not work or blow.
The working voltage of parallel capacitors is equal to the lowest working voltage rating in the combination. For example, the
total value capacitance of the combination is:-
CT = C1 + C2 + C3
CT = 1µF + 2µF + 1µF = 4µF
and working voltage = 100 volt
Series and parallel capacitors formula is a good way to find a capacitance value for replacement. Use a digital
capacitance meter and test all the results you have connected the capacitors either in series or in parallel.
|