# Step up or step down transformer

What is a step up transformer or step down transformer? It is easy to remember by visualising the following diagrams:

These pictures translate step up as:

A step up transformer has more turns on the secondary coil than the primary coil.

To work out what impact this has on voltage or current, rather than remember what the impact is Mammoth Memory suggests that you try some basic numbers into the formulas you have learnt. It is easier than remembering the results.

The impact of a step up transformer on voltage can be very quickly worked out by using:

V_1/V_2=N_1/N_2

Plug some imaginary numbers in.

(15\ \v\o\l\t\s)/V_2=(10\ \turns)/(100\ \turns)

V_2=(15xx100)/10

V_2=150\ \v\o\l\t\s

STEP UP IS AN INCREASE IN VOLTAGE

The impact of this on current can be very quickly worked out by using:

V_1\ \I_1=V_2\ \I_2

Using

V_1=15\ \v\o\l\t\s  and V_2=150\ \v\o\l\t\s

and an imaginary current of 5 amps for I_1

We get:

15xx5=150xxI_2

I_2=(15xx5)/150

I_2=0.5\ \amps

STEP UP IS A DECREASE IN CURRENT

These pictures translate step down as:

A step down transformer has less turns on the secondary coil than the primary coil.

The impact of this on voltage can be very quickly worked out by using:

V_1/V_2=N_1/N_2

Plug some imaginary numbers in.

(150\ \v\o\l\t\s)/V_2=(100\ \turns)/(10\ \turns)

V_2=(150xx10)/100

V_2=15\ \v\o\l\t\s

STEP DOWN IS A DECREASE IN VOLTAGE

The impact of this on current can be very quickly worked out by using:

V_1\ \I_1=V_2\ \I_2

Using

V_1=150\ \v\o\l\t\s  and V_2=15\ \v\o\l\t\s

and an imaginary current of 5 amps for I_1

5xx150=15xxI_2

I_2=(5xx150)/15

I_2=50\ \amps

STEP DOWN IS AN INCREASE IN CURRENT

## Conclusion

A step up transformer increases voltage.

That is, the voltage at the secondary coil is more than the voltage of the primary coil. Although the voltage increases the current is reduced.