Author Topic: Is this power supply fake?  (Read 29835 times)

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Offline zaptaTopic starter

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Re: Is this power supply fake?
« Reply #50 on: November 11, 2014, 06:59:30 pm »
@therevva, I am using a stock Makerfarm 8" Prusa I3V. It has a Ramps board with two 12V inputs. According to Coling from Makerfarm, one require 11A and one 5A.  Got the Antec this morning and installed it. The box says it has two 12V rails, each can give 18A or total of 360W on both rails. All the yellow +12V wires are shorted internally in the PSU so I don't understand what they mean by a 'rail' (each has a few connectors), maybe some passive filter inside. I had to load the 5V with a resistor, both 12V rails drop significantly when I load them. It seems to be a good fit for this printer (and recommended by Makerfarm). I may open it and remove all those wires that I don't use.

I saw people taking about using an ATX PSU as a lab bench. Was disappointed by lack of protection against shorts, at least with the Seasonic.
 

Online wraper

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Re: Is this power supply fake?
« Reply #51 on: November 11, 2014, 07:15:30 pm »
IMO should just bought that MeanWell. Unless in harsh conditions with 24/7 operation, nothing would happen to cheapest model. Different models have different parts too. Cheapest series have capxons in them, more expensive ones Japanese only capacitors. Manufacturer warranty period in the datasheet is quiet different too 1, 2, 3, 5 years. About failures written, you get what you pay for, if you choose cheap PSU for harsh and very demanding conditions, then what you should expect? At least I don't see how MW power supplies can be less reliable than consumer grade ATX power supplies.
P.S.
All those who wrote about new ATX uber technology where rails are separately regulated, DC/DC converters inside  :palm:, where did you get that stupid idea from? Maybe in some 1000W+ mega expensive ones, but not in mainstream for sure.
 

Offline zaptaTopic starter

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Re: Is this power supply fake?
« Reply #52 on: November 11, 2014, 07:50:04 pm »
IMO should just bought that MeanWell.

That's was my main choice but having the switch and power connector on the ATX makes things simpler compare to the terminal strip of the main standard power supply. My 3D printer is open frame, no enclosure, and the PSU just sit next to it on the desk.

Here is a leaflet that arrived with the Antec. See how they split the 12V connectors into 'rails'. One could think that they are independently regulated. They are not, the are connected internally, possibly through some passive filter.

 

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Re: Is this power supply fake?
« Reply #53 on: November 11, 2014, 08:02:43 pm »
Usually you get true separate rails only in high power PSUs which have 2 transformers.
 

Offline zaptaTopic starter

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Re: Is this power supply fake?
« Reply #54 on: November 11, 2014, 08:44:43 pm »
Usually you get true separate rails only in high power PSUs which have 2 transformers.

Do they still require loading of the 5V?
 

Offline a210210200

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Re: Is this power supply fake?
« Reply #55 on: November 12, 2014, 05:42:27 am »
If a power supply uses DC-DC conversion for minor rails it should be able to handle any mixed load as everything is running off the 12V rail anyways. Most new supplies just use "virtual" rails which are just having multiple over current protection groups each with their own current limit and some PC builders perfer non-ATX spec single rail power supplies that have an obscenely high current limit so that they don't have to think which rail is what when plugging in GPUs. (This only becomes a problem if someone tries to use splitters to say power a couple GPUs off one cable which is a very bad idea)

ATX supplies work fine for 12V and antec also makes good supplies. The only companies I'd really avoid are ones from things like this (Add OCZ which no longer makes power supplies I think and they also went bankrupt and I had a OCZ power supply fail on me as well),

http://www.tomshardware.com/reviews/low-cost-psu-pc-power-supply,2862.html
 

Offline zaptaTopic starter

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Re: Is this power supply fake?
« Reply #56 on: November 22, 2014, 03:41:47 pm »
Here is an interesting solution for the open Mean Well contacts, a 3D printed cover with on/off switch.

http://www.thingiverse.com/thing:40377

Too late for me but the ATX PSU works good and I removed all the extra wires so it looks clean.

Edit: and here is another one, with power connector.   



« Last Edit: November 22, 2014, 03:45:24 pm by zapta »
 


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