Mu Origin power brick

[Godzil]

Hey everyone,

Just found that campaign today, but yet when I read it I do have the impression to read a lot of bullshit (and when I look at properly design power brick with lower wattage, I don't see how they could get that without making a lot of sacrifices on either voltage stability or on safety.

https://www.kickstarter.com/projects/muone/mu-one-the-worlds-thinnest-45w-international-fast

And wtf about "Galium Nitrid" to achieve 90% efficiency?! GaN is for me some "old" LED technology and have nothing to do with power supply.

Also their PCB which they claim to be "initial PCBA" looks really like an off the shelf product (nice label on it!)

(I'm also really concern on the safety of their plug removal mechanism. their thing seems to be super easy to remove and going to defeat all standard socket protection.

[Gyro]

And wtf about "Galium Nitrid" to achieve 90% efficiency?! GaN is for me some "old" LED technology and have nothing to do with power supply.

The Gallium Nitride is used in the high efficiency Mosfets, not the LEDs!  Try a search.

[Godzil]

Ok since ~2010 not really new technology.

[Cyberdragon]

TOTAL

Nothing they say is inherently wrong. It's what they DON'T say. The Ah rating!

Yeah, sure, 45W, piece of cake! A pocket car jumper outputs way more! But for HOW LONG?! Five minutes?

The fact that it has in internal mains converter is even worse! They have to either compromise on battery size, or PSU size (and thus how fast it charges itself).

They keep going on about "magic". Well no amount of "magic" is going to overcome their piss ant little lithium cell's tiny capacity!

[ArdWar]

GaN FETs are indeed (one of) the frontier tech in switching power supplies. They're pain in the rear to design properly, and if you look at them the wrong way they'll instantly blows up.
But when done properly they offer very low on resistance and gate charge, and most of the packages also minimize parasitic inductance. That enable them to be operated at very high frequency, greatly reducing component size without sacrificing efficiency.

By the way, does anyone make 500V GaN FET?

[Kean]

@Cyberdragon What battery?

[Cyberdragon]

@Cyberdragon What battery?

Wait...is this not a battery? i thought this was a power bank?

Then what's the point? Who wants just a lame wall charger...

[CM800]

@Cyberdragon What battery?

Wait...is this not a battery? i thought this was a power bank?

Then what's the point? Who wants just a lame wall charger...

I for one see the value in a very compact wall charger...

My laptop's charger is thicker then the laptop, not to mention the GB plug.

[NiHaoMike]

Also, take an eye on capacitive isolation technology. They are not galvanic isolated, but UL has given them a green.

I saw a Maxim application note on using capacitors for power isolation and could see it being done with Y rated capacitors, but I wonder how much power could realistically be transferred that way. I have also read about piezoelectric transformers, but have never seen them being used for anything other than small CCFL inverters.

[ConKbot]

Ok since ~2010 not really new technology.

That's like saying "silicon microprocessors, ok, since ~1970 not really new technology"

EPC's current gen GANFETs (engineering samples making it to digikey currently ) have a RDSon * Qg product that is quite top notch, beating Si MOSFETs by decent margin, all in tiny little die sized packages. 

Price on the other hand though, not so competitive unless absolutely need the tiny size and high frequency performance.

[Nerull]

You guys know you don't get points for being the first to scream bullshit on a product if you don't even know what you're talking about, right?

[SiliconWizard]

I saw a Maxim application note on using capacitors for power isolation and could see it being done with Y rated capacitors, but I wonder how much power could realistically be transferred that way.

Power electronics guys are having more fun than that. Check out this: http://www.helixsemiconductors.com/pages/applications/mains-voltage-solutions

The schematic diagrams are not exactly accurate, but I won't reveal too much before their products debut.

Looks pretty cool.
I've done this kind of stuff for digital signal isolation and it worked great. Using this to transmit significant power seems to have some challenges, but that's certainly interesting.