What are some good low-voltage DC power supplies/brands in the US? - Page 1
Forum section: electronics / beginners

author: Cyber Akuma
author_rank: Regular Contributor
timestamp: July 27, 2022, 07:54:19 pm
content: Back when most of my projects were simply powered off of USB it was not hard top find a good quality power supply (Mostly stuck with Anker brand products), but now some of the DIY electronics projects I want to do require me to power them directly with 5V from wires I solder on or barrel connectors. And I am not sure where to find a good quality AC to DC adapter that uses barrel connectors. Sure places like Amazon, eBay, AliExpress, etc are flooded with them... but the vast majority of them are rather cheap in build and quality, and for the devices that will be doing any sort of audio or video work, poor quality ones can effect the quality of their output. I don't know where to even begin looking for good ones or what places or brands would be good ones to look for.Or what good electronics shops there might be in Illinois to try my luck locally.I was considering just getting an Anker USB "charger" again, and getting a USB to 5.5mm x 2.1mm barrel cable, but those seem to top out at 2A, while I think that will be ok, I was planning to get at least a 3A PSU just to be safe, so that idea won't work out.I also tried my luck with digikey (Couldn't find any on Mouser) when then I realized that I have no idea if any of these brands are even any good.... plus I am pretty sure these are overkill:https://www.digikey.com/en/products/filter/ac-dc-desktop-wall-adapters/130?s=N4IgjCBcoCwBxVAYygMwIYBsDOBTANCAPZQDaIATDAJxgDsEAuoQA4AuUIAymwE4CWAOwDmIAL6EArBUQgUkDDgLEyIAMxxqABgoA2EMxDtOPASPFS6s%2BYryESkcmrBwXMEIWeu4kj%2BpcuVp4BcAjB3tR%2BXmDaUQG0ca7UMuExaoku6YbGkNx8QqIS4BRW0HJoWHYqjiC6dPBhIHAwampaBqwcuaYFFuBgFO1lNpXKDuSDYJLU7oT0FJrpc3R0er6EFCUxKZRacBQaflQrWvrZXXlmhXPUmtYVSvaq7YxFALQyw1B8AK5jqr5XkVPuR0EgAAQAEwhAHcsJgDGIgA

author: rsjsouza
author_rank: Super Contributor
timestamp: July 27, 2022, 08:13:41 pm
content: I have been using AULT power supplies for many years - I still have some with more than ten years of use.https://www.mouser.com/c/power/power-supplies/?b=Ault%20%2F%20SL%20PowerAnother brand that I used over the years is CUI.https://www.digikey.com/en/product-highlight/c/cui/power-solutions

author: Cyber Akuma
author_rank: Regular Contributor
timestamp: July 28, 2022, 02:47:52 am
content: EDIT: Had to completely re-write this as I realized I had accidently said I needed a barrel connector with an inner diameter of 2.5 when I really need 2.1... which seems to limit my choices even more.Hmm.... not sure how well these would work out.In searching Mouser for those Ault ones, only two come up with the specs I need, but one of them is a $35 unit meant for medical use with a USB-C output, and the other does not appear to contain US plugs... and it's not clear what kind of output it has:https://www.mouser.com/c/power/power-supplies/plug-in-ac-adapters/?b=Ault%20%2F%20SL%20Power&output%20voltage-channel%201=5%20VDC~~5%20VDC%2C%209%20VDC%2C%2015%20VDC%2C%2020%20VDC&instock=y&normallystocked=y&rp=power%2Fpower-supplies%2Fplug-in-ac-adapters%7C~Output%20Voltage-Channel%201For Digikey, there are several options for CUI, but they start out at $17 and use a three-prong cable, which is pretty overkill:https://www.digikey.com/en/products/filter/power-supplies-external-internal-off-board/130?FV=ffe00082%2Cfffc0066%2Cfffc1f9e&k=&pkeyword=&pv1989=0&s=N4IgjCBcoCwBxVAYygMwIYBsDOBTANCAPZQDaIATDAJxgDsEhV1NjlNArBXSEzTPF7sWHGEOYwAbGwkNx-Oh3ktqABmU0KG6gGZtYwjDp04Hasq5sjMCpKWE6q1dTqSLHN32oczQmyxohDlV6Dj0vD3VDCg44Ci1DOk1zQmDQrQBdQgAHABcoEABlXIAnAEsAOwBzEABfVK1oEBRIDBwCYjIQHTg1WxAskDyC4vLqutSeJpa2vEISSHIdMDgwHQTulbWDTdWdHkJl1boNo9ChM5MLrbjr44hB4cgi0sqa%2BvBuRGa0LDnOxaUUySHriNQwEJg1QCeyUXTcWEUahwEFROEonThdGSHF%2BGBhQJMZGSVxglFwLFIuCOFLohgHEAkmA6WFM2JCSRI1ScjlJOAIQgk4JYoVgKzSYKeRmKMCwhimOWSWgbVy0BnGThCCkUFla5k6NFimBrB45fLPUZvCbgMAUdTTX7teZdO2yljiEIkrE0VUbV2SUwe%2BhioMMREhE5%2BiM6vzUChgSQ7V0nWFGEySNHJzFCeiqRxY3OuBnB-k7YO2gXgBhgbw5hhIjbBsK0ps6MsML11ii9AsnHq92yEqs6aiJussjzjkGNuj7VZ1mjSBcgtj0KRqBez1d83yEegZpJ12K2usZ7N74y2WH79Ony%2Bn6nXkxXuvGSEXuijp9qHx1-mOP8XBbT9oSlFYnC%2BC8v2A5F6HEbgaz9bgdURZDfyYZCM3gk4AIwnCZFUAlKztYJeg9Dg1gZEiVmIwiYijMJdSYblCPDWIwnI3RwwzVQowDaEPUTVRKW5AlBMscT0MobkknDJIhztE5ZQ9FNaNnfEVIhKM4lBZjVloD04m7D041wkA0iSWk7Tjfk-CSWwpTtXopOs5xM2cWxMzAEIQ2YlwDRM4xHOcBVxG83jKW8gM-Silwwu5ZF5DfRy00PPhjFJdK1SSuNKSMONEXgEI8rgXjM3gBNHINetxGWfYqOWCLau80Rmu7JM6u85qf2axM-WWRwZAG4ymAGk5mtKzMjjHUadQTWr40IhbbSq%2BIawWlEGu4bkFtnKz1iC2q2xJI7uysJEKKGzFhKOmwGpHCFaohXinuNBqbGZV7VGInFbBkHEdCwpgAY3JhJUUcQKISyHvohsHZTAJMKJZKiuFAyHwMcijSqRlYR0hqhjAJllMy4Uc-TCTlETCSVIZZGJIYhZSwZ6O1Gf2anrDRAMpBWRnE0c0rHAQR5zReMZ3kIABaRpkCgUoAFcOgWchaSUDIPiliAHVaP5la6bzMlqD43CaMoABMCi198hjFoRcgAT2yXACnQbAUGNoA(Although I do like that the CUI ones at least have FCC and UL certification, the Ault did not)I noticed that on Mouser, Ault was also called "SL Power Electronics Manufacture of Condor", which digikey also seem to have, but I was only able to find a single one that also requires a 3-prong cable:https://www.digikey.com/en/products/detail/sl-power-electronics-manufacture-of-condor-ault-brands/TE20A0502F01/5985408?s=N4IgTCBcDaICoFEwAYCCyCsywDFkEYQBdAXyA(I originally found much more options for SL Power... but that's when I had incorrectly chosen 2.5mm, there are much less options for 2.1)I also ran into this one by SparkFun (is their stuff any good?) that has multiple tips and an adjustable output:https://www.digikey.com/en/products/detail/sparkfun-electronics/TOL-19898/16584536?s=N4IgTCBcDaICoHkAyBaAjATgBzZAXQF8gAdmittedly I am new to using these sites so I am not sure if I am searching wrong.I noticed that "Tensility International Corp" and "GlobTek, Inc." would come up a lot when I was searching for these, any experience with those if they are any good? I have no idea if Mouser and DigiKey carry cheap poor quality parts too or not.

author: mariush
author_rank: Super Contributor
timestamp: July 28, 2022, 05:38:20 am
content: If you make a product with a barrel connector, you should really consider adding a dc-dc converter IC in them, to convert 5v ... 12v to 5v or whatever your product needs. It's maybe 50 cents in parts.If your device needs 2A+ on 5v, it would be much cheaper to get a 9v or 12v wall adapter and you'll have less voltage drop on the cable between adapter and your device.Also, you protect your device as well, end user may pick a random adapter with same barrel jack (on purpose or accidentally) and plug it in your device and could damage the product with higher voltages.Wall adapters with a standard USB output are more mass produced and cheap.For example, they're as cheap as 5$ at Digikey for 1A power supplies :https://www.digikey.com/en/products/detail/xp-power/VEL05US050-US-BB/5023710https://www.digikey.com/en/products/detail/phihong-usa/PSA05A-050QL6-H/5418479You can buy separately cable with usb type a on one end and loose wires at the other, so you could quickly crimp a barrel jack connector to the other end to make your custom cable.With 2.1mm ID barrel jack, 5.5mm OD (but various lengths of plug ex 9-12mm) they have 200+ power supplies, from 4.5$ to 35$, but right now only 30 in stock.https://www.digikey.com/short/j8w7827rIf you go with 2.5mm ID, 5.5mm OD, you have 561 power supplies (~150 in stock) :https://www.digikey.com/short/8qnq4bbjThey also have a cool 5v 11w adapter with 2.1mm ID barrel jack and plugs for different countries at $15 each:https://www.digikey.com/en/products/detail/xp-power/VER12US050-JA/5726834Digikey can be expensive, for example TME.eu (European company) often has cheaper prices ( but of course, most adapters use EU or UK plugs)For example, 5v adapters start at 2.75$ each, 2.3$ (if you buy 100) ... plus VAT :https://www.tme.eu/en/katalog/plug-in-power-supplies_113628/?s_field=1000015&s_order=asc&limit=20&currency=USD&mapped_params=364:1450053;&page=1Use SORT BY price for the last quantity threshold to see the lowest prices in quantity.They have a separate section with laptop adapter style power supplies with removable AC cable so you could use various AC plugs5v adapters start at around 12$ (sort by price for the last quantity threshold) :https://www.tme.eu/en/katalog/desktop-power-supplies_113629/?mapped_params=364%3A1450053%3B9v and 12v are much more common (ex there's 190+ 12v models), starting from 5.5$ (sort by price for the last quantity threshold) :https://www.tme.eu/en/katalog/desktop-power-supplies_113629/?mapped_params=364%3A1450064%2C1450066%3Bex 12v 2A with 2.1 ID / 5.5 OD plug and with removable AC cable (the small two pin mickey mouse style one) for 6.14$ :https://www.tme.eu/en/details/posc12200d-c8-wh/desktop-power-supplies/pos/Then your AC power cable can be ~1-2$ for example with EU plug the cable is around $1 if you order 20 or more :https://www.tme.eu/en/details/ak-rd-01a/universal-and-computer-power-cords/akyga/

author: Cyber Akuma
author_rank: Regular Contributor
timestamp: July 28, 2022, 06:13:20 am
content: Quote from: mariush on July 28, 2022, 05:38:20 amThe problem it's a device I am modifying, so I am not really free to just alter it's voltage like that.QuoteDon't those cables max out at 2A though? I wanted to at least get a 3A power supply.QuoteYeah, I tried going through that list. Thing is those started out at 1A. when I sort by 3A and larger in stock, there is one $10 one and the rest start at $13-15Even if I try to see if I can make do with 2A it only adds a $9 option... and I am not sure how good those $9-10 ones are:https://www.digikey.com/short/j8w7827r?s=N4IgjCBcoCwBxVAYygMwIYBsDOBTANCAPZQDaIATDAJxgDsEhFAzAAzWsJPNgCsrrENzAVevEAF1CABwAuUEAGVZAJwCWAOwDmIAL6FedRCBSQMOAsTIgecMGEGFbYZhSE2wd5s3fPmMX08XI0IYGDpeZgQpEDkFZXVtPUJ7CkFoEzQsPEISSHIqOjpWADZ3MBKI6gCUimo4SvKeSMZKVj5q9woKBmo3GLjIJVVNHX0QAFo3DNNVAFdLPPJxCV1xsoy1ABMFCYdWwZB3WQBPaVwFdGwUNaAQuoteYeah, a lot of these seem to be designed for a UK market. Which doesn't really help me much since I am in the US and even with the plug issue taken care of sometimes shipping alone can cost a fortune.I can find cheap power supplies if I wanted to, there are many places selling such a thing for $5-7, my issue was trying to find which ones/brands are of actual good quality, not just any random one sorted by lowest price, unless that one is also of good quality.

author: mariush
author_rank: Super Contributor
timestamp: July 28, 2022, 07:11:35 am
content: Quote from: Cyber Akuma on July 28, 2022, 06:13:20 amYou could be modifying - the device has a 5v requirement , you can easily add a small pcb with a dc-dc converter that takes in a wider range and outputs 5v for the device.Could be as easy as cutting the traces under the barrel jack connector of the device, soldering your wires going to your dc-dc converter then soldering the two wires from your dc-dc converter's output (5v) to the traces originally going to the barrel jack.OR, if possible, you can remove the barrel jack from the original pcb, and solder wires where the barrel jack was, and then use a different barrel jack (maybe one that can be screwed to the case)QuoteThey're rated for maximum 2A because of the wire gauge and because of the voltage drop across the length. Most such cables use AWG24 or thinner wires, so the longer the cable length the higher the resistance, which means more voltage drop at higher currents.For example let's say you use one of the cheaper 1m cable with AWG24 wires for the power ... that means you have 2 meters of cable between psu and device in total, and the awg24 wire has a resistance of 84 mOhm per meter.So at 2A of current, you have 2A x 2m x 0.084 = 0.336v drop on the cable ... your 5v is no longer 5v, it's 4.664v at 2A - For USB the requirement is minimum 4.75v so such cable would only be good for 1A of current.There's cables that use AWG22 or even AWG20 and even AWG18 for power, but those are more expensive.For example charge only (so only power wires) usb type-a to type c for 2.5$ using AWG22 wires :https://www.digikey.com/en/products/detail/globtek-inc/USBA2C1MOUSBC-R/12546298Or this extension is 1.83 meters (6.00') and claims to use AWG 20 for the power wires :https://www.digikey.com/en/products/detail/coolgear/USBG-AA6CC/136845393A at 1.83 meters on AWG20 wires that have 33.3 mOhm per meter = 3A x 2 x 1.83 x 0.0333 = 0.365634 v drop across the cable at 3A - at 2A it's only 0.243vWith higher voltage like 12v, you have much lower current on the cable, so much less voltage drop ... a 12v 1A adapter gives 12 watts, even with poor 90% conversion efficiency, you still end up with 5v @ 2A = 10w available to a device.QuoteThe problem is the voltage drop on the cable at such high current. They'd either have to use thick wires (AWG18 for example) OR they would have to add a third sense wire to measure the voltage at the plug and adjust output voltage to keep output at plug at 5v - that adds complexity.QuoteAs I showed you, you can buy those adapters with removable AC cable, and then you can use your own AC cable with US plug.

author: Jeff eelcr
author_rank: Frequent Contributor
timestamp: July 28, 2022, 01:22:21 pm
content: Hi, you are going at this the wrong way a wall wart is rare above2.8 amp and limits you regardless of wich one or type it is.What you need is a variable power supply 3-5A metered 0-15V or 12Vthen you buy any type adaptors to fit the varrious equipment you needto power as you need them.Jeff