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Why areis this power adaptersadapter transformerless?

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occurred Jan 23, 2017 at 22:59

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edited Jan 23, 2017 at 21:23

Why are power adapters are transformerless?

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edited Jan 23, 2017 at 21:13

I saw a battery charger that converts 220V AC to 6V DC without a transformer.

Now I am wondering why many (if not all) power adapters are using a transformer, is it about efficiency or about drifting over time?

Update: This circuit is inside of this torch

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edited Jan 23, 2017 at 19:08

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edited Jan 23, 2017 at 19:01

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asked Jan 23, 2017 at 17:44

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