Power Supply A Guide to 12V PSU

syin16

Cable Smoosher
Aug 10, 2019
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You more or less answered your own question: the voltage has to be considered when looking at those ratings. As we know: Watt = Voltage x Current

So if it is rated for 5A we get...

  • 5A x 110VAC = 550W (used on the AC side, if you live in the US)

  • 5A x 12VDC = 60W (used on the DC side)

In other words: using some connector like that for AC input would work but not for the DC output. If you need a connector that can handle 12VDC / 50A I would have a look for something like the AMASS XT90.

Also note that many of those aviation connectors selling on eBay, Amazon, etc are crap. I would try to get connectors always from electronics distributors like RS, Mouser, etc.
Based on this, i live in Malaysia where the operating voltage is 240V and 50Hz. Based on the specs of the GX12-3 connector, maximum current of 5A and operating Vrms of 250V, so the max power is 5A x 240VAC = 1200W (malaysia). Technically the connector can handle that can of power right? Because i'm planning to order g-stick fm @guryhwa for power rated of 600W. Wonder if the connector he used will be sufficient? Try asking him about all this questions but seems like he's a busy guy
 

REVOCCASES

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Based on this, i live in Malaysia where the operating voltage is 240V and 50Hz. Based on the specs of the GX12-3 connector, maximum current of 5A and operating Vrms of 250V, so the max power is 5A x 240VAC = 1200W (malaysia). Technically the connector can handle that can of power right? Because i'm planning to order g-stick fm @guryhwa for power rated of 600W. Wonder if the connector he used will be sufficient? Try asking him about all this questions but seems like he's a busy guy

Gury has quite some experience and knowledge about that stuff. Certainly more than we all together. 😅 I am sure he will use connectors suitable for his products when you order a complete set from him.
 

BaK

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May 17, 2016
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In general I would recommend to always stay within ratings given by the manufacturer.

My personal experience is: I had (no-name / generic) connectors failing way below their claimed ratings but I also had connectors which would work just fine at almost double of their official ratings. Sometimes it depends on the quality and if the manufacturer considered safety margins. Luckily I have access to HiPot and Load Testing equipment so I can check connectors before using them.

The two product pages you linked look pretty similar to me. Maybe one of those are better insulated. Or there could just be an error in one of the descriptions. Not sure.

As @Valantar pointed out, the solder terminals look pretty close to each other. For higher voltage applications where safe creepage distance cannot be maintained there should be some separators in between. If there there is not enough space for separators, @Valantar 's idea of using epoxy is also sometimes used.

I have no experience with CnLinko products so it would be a wild guess to say it's safe to use. If in doubt, I would always ask the supplier / manufacturer if it's safe to use for your application. Or just go with a connector from a well known brand where you can be sure that ratings match with your application.

I asked two electrician friends here.
First one agreed with my calculation and said I will be good, but only until I showed him the connector for real and he realized how small it is.
He then changed his mind telling me the pins are indeed small and close to each others for a 250V usage.

Second one was embarrassed to give me an clear answer, he ended up asking me if I always will be around when the computer will be running. Which I think says all...

That's why I sent a message to CnLinko, I will report here what they say if/when they answer.

But I guess I will have to switch to a more common C6 socket :\
 

Curiosity

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All I can say to the credit of XT/MR/MT connectors is that gury uses them in a few/ several of his power supply units and cases seemingly with no issue.
You're right though, I'm pretty sure those connectors I mentioned are generally designed for use with batteries for RC and other hobby electronics.

Maybe I should find a different connector for my power inlet though, i chose the MR30 because of it's small size, at the time thinking I had almost no space to fit a power inlet. Case revisions have left me with more empty or at least potentially empty space than when I made that decision almost a year ago (D:)
 

Choidebu

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Aug 16, 2017
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Just to chime in,

I had my doubts about MR/MT connectors for AC which was then confirmed by @petricor 's thread (for ~800W application).

Just don't - the plugs and sockets' connection will arc at that wattage, and even if you only intended it to be internal connection, you'd have to trust yourself to do a very good job at soldering and insulating the cables running _from_ them.

GX16 aviation connectors looks cool and generally safer against arcing because the female leads are further in the plug insulation than XT/MR/MT families. The safest is of course IEC combos, because on top of recessed female leads, if you look closely they always make ground pins connect first before hot/live leads preventing arcing.

The only gripes I have with GX16 is the fact that you have to solder your own wall to female plug cables, as nothing is available off the shelf. On that point it's the same thing with XT/MR/MT - you have to trust yourself to solder the cables well enough.

With IECs, you'd only need to worry abt soldering the socket. You can go crazy with the heatshrink insulation - hot glue, epoxy or electrical tape - doesn't matter since it's inside the case and doesn't need to look pretty or compact enough to fit a plug's housing.
 

Phuncz

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Interesting. I always thought arcing was voltage dependent, not amp dependent.
 

Choidebu

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Without wanting to sound like I actually understand the physics behind it (I consider myself like @Valantar , a mere back alley illusionist)....

Spontaneous arcing in exposed conductor is indeed voltage dependent.

But this phenomenon of current burning through insulations on the short instance of an electrical connection being made (or even multiple connect and disconnect, like when we wiggle our way in then microscopically connections are made then undone then made and so on until it's finally _really_ made), I just conveniently call arcing as well for lack of my knowledge of better word.

Now this 'arcing', in my observation, is dependent on target input impedance, contact area, max current the supply can provide, and thickness of insulation material between live/lead and its return path.
 
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infoberg

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Mar 23, 2021
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Has anyone seen this pcie form factor power supply before?
12v 5.4 a for a total of 65w, could be a cool use with an Apu only build in a small case.

Interesting concept! But 65W sounds like it's suitable only for very small builds, which mostly don't have place for any PCIe card, right?
 

Valantar

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Has anyone seen this pcie form factor power supply before?
12v 5.4 a for a total of 65w, could be a cool use with an Apu only build in a small case.

That's really neat! Seems like it would be a perfect fit for something like a Lazer3D HT5 build with a low-power APU.
 

Curiosity

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@infoberg
It's true, most build that would be happy with just 65w don't have room for a pcie device. But I imagine there are a few use-cases. The only off the shelf use I can think of would be a minibox m300, it's 3.7l and has a single pcie slot over the Mobo but usually relies on a picopsu running off a brick. It could also have a place is custom jobs.

@Valantar the only issue I see there is that unless I'm wrong, it's a full height device.
But maybe it could be made to fit somehow.
I imagine if one felt like it it could also be used to power an APU with a rouuugh diy egpu. This power the Mobo/Apu package, then you have a pcie slot open to accept a GPU on a riser that combined have their own 12v supply. Have both powered off tand connect the GPU, then apply power to the gpu, then mobo, then actually hit the power switch.
I've kind of tried that rough idea before and it functioned.
It was jank af tho
 

Valantar

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Jan 20, 2018
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@infoberg
It's true, most build that would be happy with just 65w don't have room for a pcie device. But I imagine there are a few use-cases. The only off the shelf use I can think of would be a minibox m300, it's 3.7l and has a single pcie slot over the Mobo but usually relies on a picopsu running off a brick. It could also have a place is custom jobs.

@Valantar the only issue I see there is that unless I'm wrong, it's a full height device.
But maybe it could be made to fit somehow.
I imagine if one felt like it it could also be used to power an APU with a rouuugh diy egpu. This power the Mobo/Apu package, then you have a pcie slot open to accept a GPU on a riser that combined have their own 12v supply. Have both powered off tand connect the GPU, then apply power to the gpu, then mobo, then actually hit the power switch.
I've kind of tried that rough idea before and it functioned.
It was jank af tho
That's a pretty decent idea. Could probably be made to work with some sort of electronic power switch for the external PSU, i.e. one that turns it on once there's power internally. It would need to react quickly, of course.

Btw, the product page says "low profile extension card format", so it should be half-height.
 
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Curiosity

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That's a pretty decent idea. Could probably be made to work with some sort of electronic power switch for the external PSU, i.e. one that turns it on once there's power internally. It would need to react quickly, of course.

Btw, the product page says "low profile extension card format", so it should be half-height.
I hadn't noticed that, looking closer iat it it does seem to be half height. Very interesting.
Genuinely tempted to try to get my hands on one. I've been considering getting the kontron d3664-b but haven't mentally committed yet, but if I did it wouldn't hurt to get both at once.
 
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