# Basics Transformer Calculations

Learn how to perform basic transformer calculations on this video on basic transformer calculations.

0 Learn how to perform basic transformer calculations on this video on basic transformer calculations.

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Let’s run some basic transformer calculations assuming it is perfect with no losses. If we had a transformer with 1000 turns on the primary and 100 turns on the secondary, and we supplied it with 120 volts, what voltage would we see on the secondary side?

We can use this formula to find that out and we see the answer is 12 volts. So this is a step down transformer. What if we only knew the output voltage and the amount of turns? Well we could find the input voltage using this formula. And if we input the values we get this answer.

If we wanted to find the number of turns on the secondary side and we knew the voltages and primary turns, then we could use this formular to get our answer.

If we wanted to find the number of turns on the primary side we could use this formula and this will give us the answer.

If we had a current of 1.2 amps on the secondary, then we find the primary current using this formula and we see the answer is 0.12 A. We could also find the answer if we knew the secondary current and both voltages by using this formula. If we knew the current on the primary side and the voltages of the primary and secondary we could find the secondary current using this formula. Or we could find the answer by using this formula.

We could also find the answer by using this formula we then check that the power is the same on both sides of the transformer by multiplying the voltage and current.

Lets now consider some step up transformer calculations. If we had 100 turns on the primary and 200 on the secondary, and we supplied it with 120 volts, what voltage would we on the secondary? Well we can use this formula to find that out so we see the answer is 240 volts so this is therefore a step up transformer. What if we only knew the output voltage and the amount of turns?

Well we could find the input voltage with formula.

If we wanted to find the number of turns on the secondary side and we knew the voltage and primary turns then we could use this formula.

If we wanted to find the number of turns on the primary side then we could us this formula.

If we had a current of 1 amps on the secondary then we find the primary current by using this formula and  w se the answer is 2 amps. We could also find the answer if we knew secondary current and both voltages by using this formula. If we knew the current on the primary side and the voltage of the primary and secondary, we could find the secondary current using this formula. Or we could also find the answer by using this formula. If we knew the number of turns and then we check the power is the same on both side of the transformer by multiplying the voltage and current.