Where to buy flyback tranformers - Page 1
Forum section: electronics / projects

author: Morad Tamer
author_rank: Contributor
timestamp: September 09, 2024, 08:47:00 am
content: Hello all,I have been recently tasked with making a 5V 2A SMPS. Initially I picked the flyback topology thinking it should be able to handle 10W easily and that I should find many reference designs as it is very popular. I found plenty of controller ICs but practically no tranformers. I looked through Mouser, DigiKey and LCSC.After consulting Google, I found that practically all flyback transofrmers are being custom designed and manufactured. So I was wondering 1) if there's any generic tranformer I can use? and 2) if there's no running away from a custom designed transformer, how do I approach its design?Thank you

author: squadchannel
author_rank: Frequent Contributor
timestamp: September 09, 2024, 08:59:45 am
content: Usually, the TI or ADI datasheet lists the the transformers that should be used in combination. Is it not on the datasheet?

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 09, 2024, 09:02:15 am
content: Wuerth has a range of Flybacks that were used in various reference designs.https://www.we-online.com/en/components/products/pbs/cm/pcd/mid_power_magnetics/mid_offline_flyback_transformersThey also offer a custom service.On a somewhat related note: I don't know your application or constraints but getting something off the shelf is a better idea in a lot of cases.

author: Morad Tamer
author_rank: Contributor
timestamp: September 09, 2024, 09:11:15 am
content: Quote from: squadchannel on September 09, 2024, 08:59:45 amConsulting the TI WEBENCH Designer does actually provide part numbers and full BOM for the design (yes including the transformer) but that design was really expensive.Quote from: Ice-Tea on September 09, 2024, 09:02:15 amThe problem is I'm really budget constrained, the circuit to be powered by the flyabck SMPS costs around 3 dollars, while TI's design is 4 or 5 dollars.

author: moffy
author_rank: Super Contributor
timestamp: September 09, 2024, 09:42:09 am
content: Quote from: Morad Tamer on September 09, 2024, 09:11:15 amCost of a BOM is dependent on the quantity, what quantity are you looking at?

author: ArdWar
author_rank: Frequent Contributor
timestamp: September 09, 2024, 09:44:47 am
content: What's the expected production volume? For very low amount you can buy core & bobbin parts and wind it yourself.

author: jonpaul
author_rank: Super Contributor
timestamp: September 09, 2024, 09:55:04 am
content: location? qty/yr EAU?j

author: Smokey
author_rank: Super Contributor
timestamp: September 09, 2024, 10:15:18 am
content: Do you need isolation? If not, maybe skip the flyback and just buck.

author: youngda9
author_rank: Regular Contributor
timestamp: September 09, 2024, 01:58:00 pm
content: Quote from: Smokey on September 09, 2024, 10:15:18 amYes, need to list the specs. Vin? Isolation required? Once that is known, I can probably point to a datasheet provided design since 5V@2A is quite common.

author: Morad Tamer
author_rank: Contributor
timestamp: September 09, 2024, 02:53:27 pm
content: I'm looking for maybe 10k units initial run. however won't the problem still occur that the SMPS is more expensive than the rest?I'm actually considering Non-Isolated Buck right now as it really scales far batter than flyback but I'm not sure if that can handle 10W straight from the wall.

author: Morad Tamer
author_rank: Contributor
timestamp: September 09, 2024, 02:56:29 pm
content: Quote from: youngda9 on September 09, 2024, 01:58:00 pmIsolation isn't required but that was my default thinking so as not to get roasted by Big Clive and Dave (Hello, Dave or Big Clive. In case you are reading this)It needs to accept 85 -265 Vac (120 - 375 after rectification) and step it down to 5V

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 09, 2024, 03:39:48 pm
content: https://www.power.com/products/linkswitch/linkswitch-tnzWhether or not you'll get roasted by Big Clive depends on whether you need isolation or not ;-) If it is not a safety requirement, why not ;-)

author: Morad Tamer
author_rank: Contributor
timestamp: September 09, 2024, 03:58:42 pm
content: I do believe isolation isn't be required as the device in question should be installed by an electrician and has no direct interaction with the user, but I know some guy out there is going to DIY install modify it anyway

author: langwadt
author_rank: Super Contributor
timestamp: September 09, 2024, 04:05:26 pm
content: Quote from: Morad Tamer on September 09, 2024, 02:56:29 pmso a bog standard USB charger, can you even get the parts for what a tested and approved off the shelf supply cost?

author: youngda9
author_rank: Regular Contributor
timestamp: September 09, 2024, 05:08:42 pm
content: Quote from: Morad Tamer on September 09, 2024, 02:56:29 pm90 ~ 264 VAC, 5V @ 2A outputhttps://www.digikey.com/en/products/detail/rohm-semiconductor/BM2PDA1Y-EVK-002/2253262390 ~ 265 VAC, 5V @ 3A outputhttps://www.digikey.com/en/products/detail/stmicroelectronics/STEVAL-SMACH15V1/9477658