Voltage Step Down

I'm planning to step down voltage from 220V to 3V to power a relay to drive 13A AC load. However, when I checked the Buck converter Module datasheet I found it can handle only 200 mA, I'm wondering if I turn on the load with 13 Amps would it burn the converter, given they both powered from the same source. if yes, how can I limit current to buck converter.

I'm wondering if I turn on the load with 13 Amps would it burn the converter,

No because the converter is only supplying current for the relay’s coil. The 13 amps of the contact are not connected to the coil in any way. In fact that is the point of the relay.

The input current is not the output current for that module, you will have to look up what the output current is, but it will probably be at least 2A.

However what is the D.C. current rating of those relay contacts? It only shows the AC ratings and it is not clear from your diagram if the load is AC or D.C.

Your 3.3V power supply module: http://www.hlktech.net/product_detail.php?ProId=63.
It can output 1.5 A

Do you know if the relay module is made according to the rules for mains voltage ? I don't think so.
Do you know if the relay can switch a 13A load ? I don't think so.

Did you make that drawing yourself ? It can be drawn in a better way.
The power supply module is powered by the mains. That is good. Turning on or off the load does not change that.

I prefer a SSR (Solid State Relay) that accepts a 3V logic signal. For example a SSR-25DA from a good brand. The cheap ones might not accept a 3V signal.

Uhm ... you have the relay power supply module connected to the NO switched output of the relay, so the good news is that it'll consistently pass the most stringent energy efficiency standards.

do you mean it will consume power even it is off?

Ummm, unless the diagram has been re-drawn, the supply is shown on the right hand side.

You seem to have assumed it was drawn as we expect it to be with “flow” from left to right. :laughing:

Yep, you have assumed correctly, as I haven’t, but I did find something down that rabbit hole…

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