The 2012 el-cheapo Power Supply Roundup

Aywun A1-1000

Those of you who read my review on the Aywun Megapower Elite 550W may recall that in the beginning of the review, I mentioned that I have come across some of their lower end power supplies, and that they were the kind of power supply which would appear in this roundup. The unit we have here, the A1-1000 is one of the ones I was referring to. This is Aywun’s absolute cheapest, bottom of the range unit, and is rated at 320W.

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Unlike the Elite 550W, this one looks to be another 5V-heavy unit, which would be better suited to an older PC with no 12V CPU connector

Load Testing

Test 1 (116.84W Load – Cold)

Rail Load Voltage Ripple
12V 4.87A 12.17V 52.0mV
5V 4.98A 4.98V 64.0mV
3.3V 9.97A 3.29V 87.6mV
−12V 0A −12.24V 20.0mV
5Vsb 0A 4.97V 23.0mV
AC Power 147.08W
Efficiency 79.44%
Power Factor 0.61

 

Test 2 (207.98W Load – Cold)

Rail Load Voltage Ripple
12V 9.8A 12.25V 89.2mV
5V 9.9A 4.95V 69.8mV
3.3V 9.97A 3.29V 94.6mV
−12V 0.1A −12.39V 56.8mV
5Vsb 0.98A 4.92V 81.2mV
AC Power 255.03W
Efficiency 81.55%
Power Factor 0.59

 

Test 3 (265.13W Load – Cold)

Rail Load Voltage Ripple
12V 14.56A 12.13V 103.6mV
5V 9.96A 4.98V 81.4mV
3.3V 9.97A 3.29V 93.4mV
−12V 0.11A −12.69V 77.4mV
5Vsb 0.98A 4.91V 81.8mV
AC Power 323.94W
Efficiency 81.85%
Power Factor 0.59

 

Test 4 (316.41W Load – Cold)

Rail Load Voltage Ripple
12V 19.06A 11.91V 123.0mV
5V 10.06A 5.03V 88.2mV
3.3V 9.94A 3.28V 89.4mV
−12V 0.11A −13.19V 109.8mV
5Vsb 0.98A 4.9V 77.8mV
AC Power 404.79W
Efficiency 78.17%
Power Factor 0.59

 

This is the only power supply in this roundup which didn’t blow up or shut down below its labelled rating. It delivered 320W without blowing up, and it shut down when I asked for more, but it didn’t deliver a clean 320W. The ripple was always too high, and was even approaching the 100mV mark at times on the 3.3V rail – double the maximum allowable 50mV. So, like the Excel, all 10 points will be coming off the final score. The 5V rail was slightly better, but not by much. The efficiency was also very average. At least the voltage regulation was OK.

Rail Test 3 (265.13W) Test 4 (316.41W)
12V    
5V    
3.3V    
−12V    
5Vsb    

 

A Look Inside

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If I could sum up the A1-1000’s internals in one word, it would be gutless. The input filtering is missing entirely. There’s not an X cap, choke, or Y cap to be seen. Instead of a bridge rectifier, it uses four individual diodes. The ones used are only rated for 2A, which is about as low as manufacturers go. The primary capacitors are only 330µF parts made by LW, a brand I’ve never heard of before. The switching transistors are the same JD 13007s as the  switchers in the Besta PT-550.

The Secondary rectifiers are all made by JD Semiconductors. The 12V rail uses a 16F020C Fast recovery rectifier rated at 16A, the 5V rail uses a 20S45 20A Schottky rectifier, and the 3.3V rail uses a 16S45 16A Schottky rectifier. They are all just good enough to deliver the maximum labelled current. All of the capacitors are made by BH. Each of the rails only has a single capacitor to filter the ripple, and there are no PI filter coils, which is why the ripple was too high.

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The fan is branded BaoDiKai. I’ve only ever seen one or two other fans from this brand before, and both were in cheap junk power supplies. The label does tell us that this fan runs at 2500RPM. The power supply lacks a fan controller, so the fan is wired directly to the 12V output, and was easily audible throughout the testing. The heat sinks are insanely thin – less than 1mm thick. I was able to bend the tops of them upwards with nothing but my bare fingers – something which I don’t get to do very often, even with cheap and nasty power supplies. Heat sinks this thin don’t conduct heat away from the rectifiers and transistors and up to the fins very well.

Specifications and Conclusions

Real Wattage 0W
OEM Leadway Electronics/Meiji Power
PFC None
Price Unknown
ATX Connector type 20+4 pin
Worst-case voltage regulation (12v, 5v, 3.3v) 2.1%, 1%, 0.6%
Worst-case ripple (12v, 5v, 3.3v) 123.0mV, 88.2mV, 94.6mV
Worst-case efficiency 79.44%
Input filtering None
CPU Connector ATX12v (4 pin)
PCI-E Connectors 1x 6 pin
Molex (Peripheral) Connectors 4
FDD Power connectors 1
SATA Power connectors 2

 

Pros: Working OPP

Cons: Can’t deliver anything with the ripple in spec, No input filtering, Inefficient, Noisy/No fan controller, Low quality fan and capacitors, Extremely thin heat sinks

Score: 0/10

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