Transformer qs, find turns ration & primary current

AI Thread Summary
A step-up transformer operates from a 12V supply to deliver 240V, with a secondary load of 60W. The turns ratio can be calculated using the formula Vp/Vs, which gives a ratio of 1:20. The primary current can be determined using the power equation P = V * I, leading to a primary current of 5A. The discussion clarifies that the primary voltage (Vp) is 12V, secondary voltage (Vs) is 240V, and the power (P) is 60W. Understanding these values is crucial for solving the transformer-related problems.
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Homework Statement


A step up transformer is designed to operate from a 12V supply and to deliver energy at 240V. If the secondary winding is connected to a 60W, 240 V lamp, determine:

a) the turns ratio of the transformer
b) the primary current



Homework Equations



P primary = P seconary

Vp/Vs = Is/Ip = Np/Ns

The Attempt at a Solution


-ok...well, I don't know how to do this at all, my textbook only had really straight forward questions where the info for primary and secondary was directly given...please help
 
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First question to answer: Is this a step-up or step-down transformer?
 
kuruman said:
First question to answer: Is this a step-up or step-down transformer?


-it's a step up

that means Vp is less than Vs, but Ip is greater than Is


i don't know how to identify the P, Vp, Vs from the info...
 
What is hooked up to the power supply is the primary. So what is Vp?
 
kuruman said:
What is hooked up to the power supply is the primary. So what is Vp?

so Vp is 12V and than I guess Vs is 240V and P is 60W.
 
Can you find the turns ratio now? What about the current in the primary?
 

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