Power supply types

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bplummer
 
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Power supply types

Post by bplummer »

Hello all,

I was just reading about AC to DC encapsulated power supplies. Seems like an interesting option.

Anyone have any opinions about using them as part of a project? For example, to power a stand alone Arduino or a relay like this one http://www.mouser.com/ds/2/468/RAC10-C_277-306163.pdf?

There must be some reason I don't see them being used in projects by anyone...

Thanks for your input.

Jet

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Renate
 
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Re: Power supply types

Post by Renate »

The biggest problem with them is that you need to connect a power cord to them somehow.
That means that any system with this as a component is not automatically safety approved by whichever authority has jurisdiction.
Buy a UL (or CE or whatever) approved "wall-wart" and you are all set.

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bplummer
 
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Re: Power supply types

Post by bplummer »

I've read a lot of complaints about how "wall warts" are very poorly regulated. For example, I've read that some users will buy a 12v psu and it will actually output 14v to 16v or will drop to below 10v when connected to a load. I know that power supplies have to be matched to the power consumption requirements very carefully so that may explain some of the complaints.

However, I am really just interested in why I don't see encapsulated power supplies used in projects since they appear to have a large number of advantages over "open frame" types.

Thanks

Jet

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adafruit_support_mike
 
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Re: Power supply types

Post by adafruit_support_mike »

The main reasons are cost and complexity. Any well-behaved power supply will cost more than a "this should be about 12v" transformer in terms of design effort, materials, assembly, and certification.

DIYers and people who do short-run designs have a real advantage over companies that do production in lots of 100,000 because we can spend a few extra dollars and invest a few extra hours of work to make a circuit really good. The total cost to us is a few dollars and a few hours. For a company doing mass production, it pushes on millions of dollars and millions of hours.

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