AC – DC Power Supply Non Isolated

acac-dcpower supply

I have been thinking of using LNK305P from Power Integrations to integrate an AC -DC power supply in my next project.

The application note containing the circuit is here.

What things do I need to be aware of safety wise?

I do realize that this is a non isolated power supply and should never be touched while in operation and it would be inside an enclosure to prevent any accidental touching.

I plan to use this to drive a 12v relay (coil current 75ma) and an avr circuit (max current 120ma)

Best Answer

Do your self a favour and go to premier magnetics to get a ton of designs for off-line ISOLATED switchers such as this one: -

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Adding a transformer just isn't that big of a deal. I know this is a 7V output but they will sell you a transformer suitable for 12 volt DC and give you a circuit. They have many off-the-shelf designs.