5. A step-down transformer rated at 500 W can supply 110V 60Hz (secondary) from a 220V 60Hz (primary) line voltage. If the secondary is connected to a 2.5V DC supply, what voltage can be expected at the primary side?
2007-08-30 02:05:15 · 5 answers · asked by andrew 1 in Science & Mathematics ➔ Engineering
i never did my own homework why would i do yours?
2007-08-30 02:17:54 · answer #1 · answered by Anonymous · 1⤊ 1⤋
I am assuming you meant to type the secondary output as 2.5v AC not DC.
Step downs have a ratio based on the turns of wire in the coils on the primary and secondary sides. If it has a 2:1 ratio (could make 110 from 220) then the same ratio would mean that 5V came in on the primary side.
When you see 2.5V DC it is resulting from 2.5VAC being rectified and filtered to make it into DC but transformers are not DC devices themselves.
2007-08-30 10:56:29 · answer #2 · answered by Rich Z 7 · 0⤊ 0⤋
There will be a brief glitch seen at the primary, settling quickly to zero output. Transformers cannot couple DC.
If the supply was an AC supply, then appying it to the secondary would give a step-up to 5VAC at the primary. Remember that transformers work in any direction, despite the fact that we usually call one winding the primary and the other the secondary. An input can be applied to either, and the output taken from either.
2007-08-30 09:39:18 · answer #3 · answered by Gary H 6 · 1⤊ 0⤋
Transformers work with AC. DC voltage saturates the transformer which results in zero output. Although DC produces a magnetic field, it is not changing, and therefore does not produce an output. Transformers require a changing magnetic field to induce an output on the secondary
2007-08-30 10:08:10 · answer #4 · answered by T L 2 · 0⤊ 0⤋
Transformers do not work with dc current. You will only get a transient spike when the connection is made or broken but no steady voltage.
2007-08-30 09:17:02 · answer #5 · answered by rich 2 · 1⤊ 0⤋