Hello !
Some time ago this PSU along with 3 others landed on my bench for testing.
Well what can I say. It works. The diodes switch clean and don't ring, the caps work well together without resonance, the regulator performs up to spec and is stable, and the chokes attenuate mains noise quite spectacularly, which is very nice.
Among the others tested :
- one worked pretty well within its limits (ie, no HF filtering components = everything gets through)
- one oscillated on its intended load
- the last one (apparently some well regarded "audiophile product" which I'm not going to name, actually a bad copy of Jung superreg), had some form of cancer in the feedback loop which made it amplify the mains noise up to 20dB at specific frequencies and also act like a radio receiver, this one was fun to probe with the network analyzer
So, this PSU feels like it's been thoughtfully designed and not just a bunch of stuff thrown at random on a board.
I know, I should post a ton of graphs etc. But really, stuff that just works is boring.
Nice work JP. You guys can buy it, no problem.
Some time ago this PSU along with 3 others landed on my bench for testing.
Well what can I say. It works. The diodes switch clean and don't ring, the caps work well together without resonance, the regulator performs up to spec and is stable, and the chokes attenuate mains noise quite spectacularly, which is very nice.
Among the others tested :
- one worked pretty well within its limits (ie, no HF filtering components = everything gets through)
- one oscillated on its intended load
- the last one (apparently some well regarded "audiophile product" which I'm not going to name, actually a bad copy of Jung superreg), had some form of cancer in the feedback loop which made it amplify the mains noise up to 20dB at specific frequencies and also act like a radio receiver, this one was fun to probe with the network analyzer
So, this PSU feels like it's been thoughtfully designed and not just a bunch of stuff thrown at random on a board.
I know, I should post a ton of graphs etc. But really, stuff that just works is boring.
Nice work JP. You guys can buy it, no problem.
Sure.
The transformer I would like to buy is rated at 6.3VAC @ 230VAC supply. So it's "wrong" only by a small margin, but added to this we have 240VAC in Australia (I just measured 245VAC at the wall) so -
240 divided by 230 multiplied by 6.3 = 6.57VAC secondary output. After the rectifier this should be 7.8VDC.
I will be powering a BeagleBone Black which draws approx 400mA @ 5V - I believe this is much less than a SBT draws.
Would I be putting too much heat into the regulator?
If so, throw some diodes or resistors at it- a CRC before regulation, tuned right, is usually a good thing.
It will be OK but a 5V transformer will be slightly better. So no worries. If you still have choice try to find a 5V 1A (or more) one and otherwise just buy the 6.3V one.
BTW your calculations are off as most transformers give way higher voltage than expected. Their output voltage is specced at max. load. The smaller the transformer, the higher the unloaded output voltage (in general).
Farnell Australia has the Hammond 185C10 transformer. Please check that one if the size is not too large. It has 2 x 5V which means you can use 2 x PSU if needed.
I can understand why you don't want to name it, but I think it would be a public service...
You should! I am sure I am not the only one who really would like to see the measurement results.
Thanks jean-paul, that Hammond transformer will be good for me.
Another question: your filtering is on the DC side of the regulator - should we consider an AC filter? Something like this -
FN9222U-3-06 - SCHAFFNER - IEC FILTER 3A STANDARD EXTENDED FLANGE | element14 Australia
Another question: your filtering is on the DC side of the regulator - should we consider an AC filter? Something like this -
FN9222U-3-06 - SCHAFFNER - IEC FILTER 3A STANDARD EXTENDED FLANGE | element14 Australia
Still working at my scenario to become incredibly rich so have some patience 
Subbu checks the last layout revision. We will update the schematic accordingly and make a final BOM. I piled up a stock of Rcore transformers for European buyers and Korben69 (Phil) will do a parts GB as it seems now. So you see we are communicating and trying to make things run smoothly. "Who does what and when"....
I think including an Ampère meter will be difficult as taste may vary. If I we're you I would try to find a 3 or 5A version locally , even a second hand old fashioned one is OK. Especially the old ones are sturdy and good looking with real glass.
Subbu checks the last layout revision. We will update the schematic accordingly and make a final BOM. I piled up a stock of Rcore transformers for European buyers and Korben69 (Phil) will do a parts GB as it seems now. So you see we are communicating and trying to make things run smoothly. "Who does what and when"....
I think including an Ampère meter will be difficult as taste may vary. If I we're you I would try to find a 3 or 5A version locally , even a second hand old fashioned one is OK. Especially the old ones are sturdy and good looking with real glass.
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Hi JP and All
Yes I'm in for managing the pats GB.
Since beginning of 2015, shipping rates have changed and increased dramatically... Economic rates have collapsed
In a view to avoid astronomical prices, parcels must be less than 3cm thick.
Regards
Phil
like to get in on GB if it happens
I am a US user and would be very interested in this item when it goes to GB. Will it be posted in GB when available? I just received my Subbu DAC v3 and am starting to prep for it's build. I am fine with a PCB and suggested BOM as sourcing is a bit easier from my location. Thanks!
Steve
I am a US user and would be very interested in this item when it goes to GB. Will it be posted in GB when available? I just received my Subbu DAC v3 and am starting to prep for it's build. I am fine with a PCB and suggested BOM as sourcing is a bit easier from my location. Thanks!
Steve
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