Do you mean how to calculate the inductance and resistance of a particular choke, or how to determine the required values for a PSU design? I assume you mean the latter.
PSU current, voltage, acceptable ripple, half or full-wave or doubler, any subsonic issues? Once you understand the issues, you will be almost there for calculating the values.
PSU current, voltage, acceptable ripple, half or full-wave or doubler, any subsonic issues? Once you understand the issues, you will be almost there for calculating the values.
Yes the latter.
I'm a newbie, I know target voltage & current but I need to understand how implement the PSU to get the lower ripple possible to sound the best possible.
For example I know that before diodes I have to put a RC snubber, first question: how measure with scope if values are correct & how to calculate the values of RC.
Why the resistor in series with choke have to be 0R47 or low value?
Why not choke & resistor in ground rail?
Choke is better alone or common mode if used also for ground?
etc.
"Lowest ripple possible" is not a useful criterion. It is quite normal for a newbie to want to over-engineer a circuit, so you are in good company!
The choke and smoothing cap act as a low pass filter, as the choke and cap act as an AC potential divider. You need to calculate/measure/simulate the ripple on the first (reservoir) cap, then consider your amp circuit PSRR. Taken together these tell you how much the PSU has to suppress ripple. This is of course is elementary PSU design theory which you can find in a book or on the internet.
The choke needs no resistor in series. On the contrary, often the choke resistance itself is larger than we would like. The choke could be put in the negative rail - it might even help people get their grounding right by forcing them to avoid the common mistakes.
Common mode chokes eliminate common-mode noise. Ripple is usually differential mode.
The choke and smoothing cap act as a low pass filter, as the choke and cap act as an AC potential divider. You need to calculate/measure/simulate the ripple on the first (reservoir) cap, then consider your amp circuit PSRR. Taken together these tell you how much the PSU has to suppress ripple. This is of course is elementary PSU design theory which you can find in a book or on the internet.
The choke needs no resistor in series. On the contrary, often the choke resistance itself is larger than we would like. The choke could be put in the negative rail - it might even help people get their grounding right by forcing them to avoid the common mistakes.
Common mode chokes eliminate common-mode noise. Ripple is usually differential mode.
go here He does an easy to follow calculator for you rest of his site is very good also . Hagerman Technology LLC: Design Theory
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