Why is this GE rated for 6 V, 200 mA, and 5 W?

Question

I have a genuine GE 5-1075A AC/DC power brick that says that it can provide 200 mA at 6 V (1.2 W).

My use case is that I want to power some old cassette players which I believe these are compatible with. The cassette players only list "6 V" and no current rating.

Why is this power brick listed as 5 W if it also states voltage and current nowhere near that value?

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6 volts and 200 mA is 1.2 watts. The 5 watt figure is power required from the AC to do what it does. — Andy aka, Sep 23 '20 at 13:19
Input is rated 5W max. Power loss from input to output is called efficiency. — Stefan Wyss, Sep 23 '20 at 13:20

score 3 · Accepted Answer · answered Sep 23 '20 at 13:23

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Does this help?

In other words it's only about 20% power efficient.

answered Sep 23 '20 at 13:23

Andy aka

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It could use less than 5 watts. – user253751 Sep 23 '20 at 14:34
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And it could supply less than 1.2 watts. – Andy aka Sep 23 '20 at 17:01

ocrdu · Answer 2 · 2022-07-09T09:54:27.617

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Because it consumes a maximum of 5 W on the 120 VAC side to give you 1.2 W @ 6 V on its output. Not very efficient, but there you have it.

edited Jul 09 '22 at 09:54

answered Sep 23 '20 at 13:21

ocrdu

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More likely that the input is actually 5 VA, due to high inductance and poor coupling. This is done to reduce cost but also provides a measure of safety if output is overloaded or shorted. https://electronics.stackexchange.com/questions/393802/can-a-short-circuit-in-the-output-of-a-transformer-be-dangerous – PStechPaul Jul 28 '22 at 07:34

Why is this GE rated for 6 V, 200 mA, and 5 W?

2 Answers2