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Topic: 24v ac to 5v dc power supply (Read 282 times) previous topic - next topic

kristian1980

Good day. I have a 24v ac power supply to some solonoid valves. I would also like to pull out power from it to supply my 5v dc arduino project. The hlk pm01 seems nice but input is 100-240v ac.

Can someone please recommend a proper power supply module with input 24v ac  /output 5 v dc?  3W should be ok. I will power a 4 channel 5v relay, and 1 esp 8266wifi module. I would prefer a module i can solder on a pcb.

In advance thank you for reading.

Kristian

adwsystems

That may be a tough one. I would suggest getting a DC-DC converter for 24-36VDC and rectifying the 24AC yourself with a bridge rectifier and a couple of capacitors.

wvmarle

Indeed, rectifier + buck converter, like this one, would be the most sensible. Nothing special for the rectifier, as the 24V side should be around 150 mA only for a 3W output. There must be similar buck converters with fixed 5V output as well.
This specific module has a 100µF input cap - this may or may not be enough to smooth the input, this buck converter should be able to handle some ripple on the input, it's rated 5-60V after all.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

Paul__B

OK, let's run the numbers.  CV = It ; 100µF, 150 mA, 10 ms - voltage drop 15 V.

No, doesn't sound good.  Better make it a 1 mF capacitor.

lefstin

#4
Oct 10, 2018, 07:20 am Last Edit: Oct 10, 2018, 07:21 am by lefstin
These modules might do it.


kristian1980

#5
Oct 11, 2018, 03:49 am Last Edit: Oct 11, 2018, 03:51 am by kristian1980
Thanks a lot for all replies. I will give the module lefstin posted a try first. Will also try to build a bridge rectifier and a converter. Will be interesting and learn a lot.I give you a update when tested.

adwsystems

I would not build a converter, buy one, less than $5. lefstin's converter appears to include the rectifier (square component on the left).

Paul__B

And a large input capacitor of which I was frustratingly unable to see the value in any of the photos on eBay, but which does look like at least my minimum recommendation of 1 mF.

kristian1980

Thanks. I will check the value of the capacitor when i receive the module.

lefstin

I checked mine; the input capacitor is 1 mF.

Paul__B


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