Re:The cases of consumer-grade routers on puny power supplies
by alright2565 on Thursday January 09, 2025 @06:37PM
(#42650980)
> the transformer in SMPS other than it's size which is due to the high frequency
There absolutely is. The core material is not iron, it is a material specifically engineered for the purpose. There's a very specific size gap between the two halves of the core. There's an extra sense coil for the feedback circuit.
Re:The cases of consumer-grade routers on puny power supplies
by timewizard on Thursday January 09, 2025 @07:41PM
(#42651352)
It depends on the switching frequency, and not all SMPS run at a high enough frequency to justify ferrite. On top of that ferrite is effectively just iron in a ceramic.
The gap is controlled by the cross section of the core but also contributes to EMI. The sizing concerns are typically related to the latter problem.
An SMPS can easily use an external feedback circuit and may do so for certain types of applications. For mass manufactured low current applications you can often buy them with one integrated.
Re:The cases of consumer-grade routers on puny power supplies
by Leif24 on Thursday January 09, 2025 @10:38PM
(#42652192)
If you aren't fussed about galvanic isolation there are many SMPS topologies that don't use transformers. Cheapest step down converter would be a simple buck regulator - no transformer needed!
The other problem they create, then, is high frequency noise which must be filtered out. Some cheaper adapters just dump the noise back into the mains and cause problems for _other_ devices.
Come to think of it there's a decent chance it's a /different/ adapter somewhere on his system that's causing the problem and not the size or capacity of the products native adapter.