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## Impedance transformation

May 6 • Engineering Notes • 818 Views • 2 Comments on Impedance transformation

Impedance transformation

Before understanding the concept impedance matching we must be clear about the term impedance…..

WHAT IS IMPEDANCE??

Resistance is the opposition to the flow of current.capacitors and inductors react differently in opposing the flow of ac current than they do in opposing the flow of ac current.Resistance to the flow of ac current is known as reactance.resistors react same for ac or dc.Impedance is the opposition to the flow of ac current.Includes both components of opposition-resistance and reactance.It is measured in ohms and symbolized by Z.

requirement OF IMPEDANCE TRANSFORMATION

If there is an impedance mismatch between the source and the load,there will not be maximum transfer of the power or the energy.For better understanding we can take the help of an example-the speaker of 9ohms will operate most efficiently only when it is connected to the 9 ohms amplifier.The transformers serve to transform the impedance between the source and the load.

IMPEDANCE TRANSFORMATION- A PROPER DESCRIPTION

The ratio of the number of turns in the primary and the secondary determine the impedance change.

Step up(increase)

Step down (decrease)

√ZP/ZS=NP/NS

where

ZP- it is the impedance of the primary side

ZS-it is the impedance of the secondary side

NP- it is the number of turns at the primary side

NS-it is the number of turns at the secondary side

We already know that the power in and out of the transformer is the same.for eg.If the power in is 50 watts the primary current is 5 amp and the primary voltage is 10 volts then we can determine the current and voltage flow in the secondary.When we consider the given formula P=I*E, WE will see that voltage and current will be proportional to each side of the transformer.If the power is constant and the current is doubled in the primary due to(1:2) ratio it is cut in halves at the secondary side. The inverse is true voltage.i.e just vice-verse occurs for the voltage.

In the following equations:

• Vp= primary voltage
• IP= primary current
• NP= primary turns
• VS=  secondary voltage
• IS=  secondary current
• NS = secondary turns

mathematically,
Vp/ NP = VS/ NS

IP* NP= IS* NS

impedance transformation for transfer of maximum power

1.WHAT IS IMPEDANCE TRANSFORMATION???

The ratio of the number of turns in the primary and the secondary determine the impedance change.

Step up(increase)

Step down (decrease)

√ZP/ZS=NP/NS

where

ZP- it is the impedance of the primary side

ZS-it is the impedance of the secondary side

NP- it is the number of turns at the primary side

NS-it is the number of turns at the secondary side

2.WHY IS THE IMPEDANCE TRANSFORMATION REQUIRED???

If there is an impedance mismatch between the source and the load,there will not be maximum transfer of the power or the energy.For better understanding we can take the help of an example-the speaker of 9ohms will operate most efficiently only when it is connected to the 9 ohms amplifier.The transformers serve to transform the impedance between the source and the load.

### 2 Responses to Impedance transformation

1. Impedance transformation is beautifully explained here …see this

2. The concept of impedance has been treated very well, which leads to he full explanation of Impedance transformation.