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22 March 2009
Author: Giorgos Lazaridis
Connecting Capacitors

Connecting capacitors in series

A series connection of capacitors is when the end of one capacitor is connected to the start of the next capacitors. If the capacitors are electrolytic capacitor, extra care should be taken with the polarity. The + wire of the first capacitor must be connected to the - wire of the next one, like when connecting batteries in series:

The total capacitance in series connection

When connecting capacitors in series, the total capacitance is calculated from the following series:

 1 = 1 + 1 + ... + 1 CTOTAL C1 C2 Cn

In special cases where only 2 capacitors are connected in series, there is an easier way to calculate the total capacitance using the following formula:

 CTOTAL = C1 x C2 C1 + C2

As can be seen above, the more capacitors you connect in series, the less the total capacitance becomes. In general, the total capacitance will finally be less than the the capacitor with the less capacitance.

The total impedance in series connection

The formula to calculate the impedance of one capacitor connected to an AC power source is:

 Xc = 1 2 π F CTOTAL

The more the capacitors in a series connection, the less the total capacitance becomes. Thus, the more the capacitors in a series connection, the more the impedance of the series.

The voltage drop in series connection

Same as when connecting resistors in series, the sum of voltage drops across each capacitor equals to the voltage across the whole series:

U = V1 + V2 + V3

in general:

UTOTAL = VC1 + VC2 + ... + VCn

The voltage drop across each of the capacitors is given from the formula:

 Vx = QTOTAL Cx

Where QTOTAL is the total charge of the wjole circuit and is calculated from the formla:

QTOTAL = CTOTAL x U

Connecting capacitors in parallel

A parallel connection for capacitors is when all capacitors in the circuit have common starts and ends. Special care should be taken when electrolytic capacitors are connected in parallel. Their wires should be connected in respect to their polarity. All wires with + polarity should be connected together:

The total capacitance in parallel connection

The total capacitance in a parallel connection for capacitors is the sum of all capacitances within the circuit:

CTOTAL = C1 + C2 + ... + Cn

As can be seen from the above formula, the more the capacitors in a parallel connection circuit, the more the total capacitance of this circuit.

The total impedance in parallel connection

The formula to calculate the impedance of one capacitor connected to an AC power source is:

 Xc = 1 2 π F CTOTAL

The more the capacitors in a parallel connection, the more the total capacitance becomes. Thus, the more the capacitors in a parallel connection, the less the impedance of the series.

The voltage drop in parallel connection

In a parallel connection of capacitors, same as in parallel connection of resistors, the voltage drop across each part of the circuit is the same as the total voltage U. Thus, if U=10Volts, each capacitor will have 10Volts across it's leads.

Relative pages
• Learn how to connect resistors together
• Learn how the capacitor works
• Learn how to read the part coded values
• The resistor theory
• The voltage divider theory
• Dr.Calculus: Capacitors color code calculator
• Dr.Calculus: Capacitors value code calculator
• Dr.Calculus: Standard resistor values calculator
• International unit converter

 At 29 May 2014, 18:36:18 user mike Slaney wrote:   [reply @ mike Slaney]I am trying to set up a capacitor bank of ele. caps. I want a temp storage of power, like a set of batteries, to power an inverter from a generator. I have an input of 220v dc generation and wish to pass them into a CAP bank. the caps I have are 24000mf 40vdc caps. The question is, can I put these caps in series to equal 220vdc output voltage, or am I thinking of a good way of seeing sparks? Thank You, MikeAt 14 September 2011, 6:32:53 user kenneth baris wrote:   [reply @ kenneth baris]thaha .. amazingAt 31 August 2010, 10:33:42 user hades wrote:   [reply @ hades]i love this site...it is full lessons and it is understandatable..(-:

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