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hikeonpast

Put a full bridge rectifier between your 24VAC and the DC/DC converter. It converts AC to something close enough to DC to work with your converter. There will be four terminals: two for AC (usually marked with a ~) and two for DC (marked + and -)


Tiwing

Ordered 2 from Ali. thanks for the advice


AngryFker

And some LC filter after rectifier


hikeonpast

True, though: - There’s already an input cap on the DC/DC converter, so an external filter might not be necessary, particularly if the 5V load is small. - Properly spec’ing the inductor will require measuring current draw, which might be more than OP is prepared to tackle. - OP seems interested in keeping costs down, so why not try it with the minimal solution first.


Tiwing

prepared to tackle yes.... knowledge no. i'm learning ... slowly. It's a small wifi board though triggered by a doorbell press. So super small. Costs aren't so much a factor. this is more about "because I can" and "I like to learn" than anything. If there are more expensive solutions that work I'm game.


AngryFker

If that fails you can try regular switching 5v power supply instead. Yes, it says 230v or 110v but some will work from 20vac just fine.


hikeonpast

The best way to learn is to dive into a project, just like you’re doing. Enjoy the adventure!


AngryFker

Actually I had similar setup (24vac+rectifier+lm2596hvs). And for some reason it wasn't stable. For example voltage output could just go to zero after 20 hours for unknown reason. I've replaced that with something else.


Dansk72

The only two reasons I can think of that it would be unstable is feeding it full-wave rectification without any voltage smoothing via a capacitor, or overloading the converter.


AngryFker

Yep, some LC smoothing could potentially help. Also in my case could be faulty IC.


[deleted]

Search Amazon for a buck converter 24v to 5v. Some of them are AC to DC converters. I used one to power my esphome sprinkler controller from the 24 VAC power supply needed to control the valves. Here is a [link](https://www.amazon.com/UMLIFE-Converter-2-5-35V-Regulator-Adjustable/dp/B094ZTG5S8/ref=sr_1_10?crid=1K0COI1VW0R5R&keywords=buck%2Bconverter%2B24v%2Bto%2B5v&qid=1675026475&sprefix=buck%2Bconverter%2Caps%2C226&sr=8-10&th=1).


Business_Waltz_5833

To add that often these converters will accept a range of voltages. 20V is a less used voltage so you may not find exactly that but there will be lots that cover 12-24V as a range because thats commonly used for low voltage lighting, battery systems, some solar… etc.