Power Supply 110 Volts AC to 24 Volts DC - Page 1
Forum section: electronics / projects

author: pittsallen@usa.net
author_rank: Newbie
timestamp: August 27, 2025, 07:35:46 pm
content: Hello EEVBlog forum,Looking for a circuit to build aPower supply 110 volts AC to 24 volts DC 1.5 - 2 ampsHave found lots of posts on 3v, 5, volt and especially 12 volthttps://www.homemade-circuits.com/how-to-design-power-supply-simplest-to/https://www.caretxdigital.com/https://www.build-electronic-circuits.com/power-supply-circuit/https://www.electronicsteacher.com/circuits-and-diagrams/power-supplies-and-control-schematics/ckt19_1.gifHave seen several designs for 12 volt 6, 8 and 10 amp circuits.Need to build a circuit to power a controller foran LED COB striphttps://www.amazon.com/dp/B09W5J763J?smid=A2A6WV1Z7O325J&ref_=chk_typ_imgToDp&th=1The wall wart that comes with the strip is 1.5 ampsand will supply plenty of juice for a 16 foot COB strip.I would like to replace the wall wart with a smallPCB.Any ideas?Thanks.Allen Pitts

author: Zero999
author_rank: Super Contributor
timestamp: August 27, 2025, 07:47:24 pm
content: No. Please don't build one. Buy a ready built power supply.The usual way to make one is to use a heavy transformer, bridge rectifier, smoothing capacitor and linear regulator. It's inefficient, bulky and will be much more expensive, than just buying one.Building an efficient and safe mains powered switched mode power supply is not an easy task. Even though I could do it. I wouldn't consider it, unless it needs to meet some unusual requirements and powering LED strip is not one of them.I strongly recommend buying a power supply from a reputable company such as a supermarket, or from an online distributor such as Digikey or Mouser.

author: WattsThat
author_rank: Frequent Contributor
timestamp: August 27, 2025, 10:34:22 pm
content: +1 to what Zero999 said.First and foremost, you cannot buy the parts for a home built supply for what you’ll pay for a complete, certified, safe and reliable commercial switcher supply. For example, here’s a 100W double insulated Mean Well brand supply for less than $25:digikey.com/en/products/detail/mean-well-usa-inc/LPV-100-24/7704978I would avoid power supplies from Amazon in general, as the no name generic Chinese supplies will not deliver their rated output current and more importantly, they’re not safe since the have no third party testing done. Cheap is what you get when cheap is what you pay.Also, consider alternatives to the el-cheap o generic Chinese led controls sold by Amazon with the lights, I wouldn’t install that crap in my house, ever. You can purchase commercially available supplies that provide dimming with any number of standard home automation interfaces (WiFi, Bluetooth, etc).

author: John B
author_rank: Frequent Contributor
timestamp: August 28, 2025, 12:40:25 am
content: Some of the quoted articles read like AI slop. Making a mains AC / DC PSU based on AI articles sounds like a death sentence, though thankfully the article seems to be regurgitating linear supplies based on step down transformers. Which are great for audio, but totally outdated for something like powering LEDs.As above, just grab an industrial or medical PSU from digikey or similar.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 28, 2025, 03:12:38 am
content: Try running the LED strip at 20V. If it lights bright enough, you can use a laptop PSU or a USB-C PSU and a "USB PD trigger board".

author: pittsallen@usa.net
author_rank: Newbie
timestamp: August 29, 2025, 12:12:39 am
content: Hello zero999 whatsthat John B nihaoMike and the EEVblog forum,It is seen now that it would be easier cheperand a produce a more compact product to buy a 24 volt power supply rather than building one.Have ordered the Mean Well product from Digikey.Thanks.Allen Pitts

author: John B
author_rank: Frequent Contributor
timestamp: August 29, 2025, 02:02:56 am
content: In the DIY world, I think you will find many of us prefer to do things the more difficult and expensive wayThe issue here is that a (good quality brandname) off the shelf unit will need to pass a slew of tests to ensure the secondary side is safe for human touch under a wide range of faults and age related failures. For a DIY unit, a mains step down transformer takes care of the isolation, then you can experiment with your own low voltage AC/DC converter with little to no risk. But generally you'd only need to do that with low noise requirements, such as audio applications or maybe metrology.

author: Konkedout
author_rank: Frequent Contributor
timestamp: August 29, 2025, 03:08:43 am
content: I am a power supply design engineer. I generally agree with most of the other posts responding. DO NOT ATTEMPT TO DO YOUR OWN AC/DC POWER SUPPLY.What I would do is to start with a power adapter for a laptop power supply. I have a bunch of old ones, but even new ones are inexpensive. The Dell adapters I have produce about 19-20V. If you need a bit more than that, build or buy a boost converter. That can be a great learning experience.

author: Andy Chee
author_rank: Super Contributor
timestamp: August 29, 2025, 03:30:15 am
content: Quote from: pittsallen@usa.net on August 27, 2025, 07:35:46 pmI'm more interested in your thought process. Why did you even think of attempting to construct such a circuit, rather than investigate existing off-the-shelf products on the market?It's evident from your links that you did some brief research, yet failed to research off-the-shelf devices. Why?