Where can I buy a 2-polarity power supply? - Page 1
Forum section: electronics / general

author: Ben321
author_rank: Frequent Contributor
timestamp: December 12, 2022, 11:35:47 am
content: I'm looking for a simple wallwart type power supply that will output +/- 5 volts or maybe 9 or 12 volts. It must be a dual polarity power supply, because my intended usage is to power an op-amp in a DC coupled circuit. If it was AC coupled, I could get away with using a single polarity power supply, and then just use DC blocking capacitors on the input and output. But for DC coupling there are no coupling capacitors, so the power source MUST be a dual polarity power supply.Now when I googled for a dual polarity power supply, I don't get any search results linking to electronics companies selling them. Instead I get to various posts on other forums where people are describing how to build such a power supply. But I don't want to spend my time building one. I want to buy one, so I can spend my time working on building my op-amp circuit.If you know a place to buy a dual polarity power supply (doesn't need to be anything fancy, a simple wallwart power supply would work fine) then please let me know.

author: ledtester
author_rank: Super Contributor
timestamp: December 12, 2022, 11:47:13 am
content: You can use two isolated power supplies and put them in series. For instance, two transformer-based (by which I mean non-switching) wallwarts should work well for an op-amp supply.You could also use batteries.See these discussions for more info:https://electronics.stackexchange.com/questions/153333/connecting-two-dc-wallwarts-in-series-to-produce-dual-dc-supplyhttps://electronics.stackexchange.com/questions/162362/is-it-safe-to-implement-a-split-power-supply-from-two-identical-ac-dc-adapters

author: H.O
author_rank: Frequent Contributor
timestamp: December 12, 2022, 12:40:32 pm
content: Don't know of any wallwart type supplies with dual output but dual output AC/DC power supplies are available. Digikey sells the theAimtek AMES15-5DMAZfor example.Or, as was mentioned, you could simply use two single output ones and be done with it.

author: Ben321
author_rank: Frequent Contributor
timestamp: December 12, 2022, 01:10:34 pm
content: Quote from: ledtester on December 12, 2022, 11:47:13 amI had been hoping someone here could point me to an online store that actually sold dual output power supplies, so I didn't need to build my own. My opening post made that clear. Why did you post links having to do with building such a power supply?Well I finally managed to find one on my own. Here's what I found.https://www.newark.com/xp-power/aeh45um32/ac-dc-converter-external-plug/dp/40P3656This is the cheapest power supply they sell that has +/- outputs suitable for powering an op-amp. It also has a 3rd output at +5 volts which is a nice extra feature. Unfortunately the price is a bit much. At $102, it costs more than a laptop power supply (even though it looks like one with its brick shape). Maybe there's some actual laptop power supply out there somewhere, made for a laptop that actually expects a dual-polarity power supply as its power source.

author: Ben321
author_rank: Frequent Contributor
timestamp: December 12, 2022, 01:29:37 pm
content: And here's an even cheaper one. At just over $50, it is definitely a reasonable price. It has +/- 12v outputs.https://www.digikey.com/en/products/detail/xp-power/ECL15UD01-S/4487543

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: December 13, 2022, 11:28:43 pm
content: You could also use a power splitter like the TLE2426 from TI or make up one using an OPA with sufficient output current.

author: MasterT
author_rank: Frequent Contributor
timestamp: December 14, 2022, 12:34:13 am
content: https://www.mouser.ca/ProductDetail/MEAN-WELL/RD-3513?qs=l0g2inPJSHMRps4T2qDwgw%3D%3D