I'll be starting to build a Millett NuHybrid headphone amp and I can't help but build a PSU for it as well (I don't like the idea of having a SMPS in there).
Therefore, I've "designed" the following schematic and I'd appreciate getting some feedback on it. Is there something inherently wrong with it? Could it use some improvements here and there?
I haven't decided on the diodes yet, but several options come to mind: Vishay HexFRED, Fairchild Stealth II... 1n4007? I know this might be overkill, but unless I'm shelling 10$ on a diode, it won't be a problem. In the end, I'm doing this for the fun of it mostly, so I'm not interested in the best bang for buck solution.
Hit me with your thoughts.
PS: the supply should put out 24V @1A.
Therefore, I've "designed" the following schematic and I'd appreciate getting some feedback on it. Is there something inherently wrong with it? Could it use some improvements here and there?
I haven't decided on the diodes yet, but several options come to mind: Vishay HexFRED, Fairchild Stealth II... 1n4007? I know this might be overkill, but unless I'm shelling 10$ on a diode, it won't be a problem. In the end, I'm doing this for the fun of it mostly, so I'm not interested in the best bang for buck solution.
Hit me with your thoughts.
PS: the supply should put out 24V @1A.
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Over engineered.
Why use a snubber across the diodes unless you are switching, which you are not.
1000uF supply side is adequate for smoothing and 100nF between pins 1 and 2 plus a further 100nF and a 10uF in parallel between pins 2 and 3 will be quite adequate.
C1 and the PTC are not needed at all.
Why use a snubber across the diodes unless you are switching, which you are not.
1000uF supply side is adequate for smoothing and 100nF between pins 1 and 2 plus a further 100nF and a 10uF in parallel between pins 2 and 3 will be quite adequate.
C1 and the PTC are not needed at all.
I know I went slightly overboard with the parts, but if it doesn’t affect performance negatively, I don’t see it as a problem.
Also, considering an AC input of 24V@50Hz, my calculations gave me a needed capacitance of 5000uF, to achieve Vripple of 2V. I could probably go with a higher ripple, but I’d want to stay on the safe side, expecting variations in mains voltage.
Also, considering an AC input of 24V@50Hz, my calculations gave me a needed capacitance of 5000uF, to achieve Vripple of 2V. I could probably go with a higher ripple, but I’d want to stay on the safe side, expecting variations in mains voltage.
Overengineering can sometimes affect performance negatively. I would start by getting rid of the 'bypass' caps. At best they do no good; at worst they can introduce resonances. The capacitor (singular!) at the output of the regulator should be whatever is recommended in the datasheet.
There is no need for expensive diodes and diode snubbers; choose snubbers (on cheap basic diodes) or expensive diodes.
The most important thing about PSUs is getting the grounding right, as many people discover after getting it wrong.
There is no need for expensive diodes and diode snubbers; choose snubbers (on cheap basic diodes) or expensive diodes.
The most important thing about PSUs is getting the grounding right, as many people discover after getting it wrong.
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