Linear PS universal?

[esreuter]

Hey all,

I am new to they DIY scene and am making my first build a module kit.

I have learned so much about what each component does and its use, this is all very fascinating.

I would like to learn if Linear PS are universal, for example, i really like the PS on connex,

Connexelectronic

can this PS be used with another vendors boards, specifically,

Class D Audio Class D Audio CDA-258

it appears that the class d PS and the Connex PS are similar in design, the connex has 4 rectifiers, I can only see one on the Classd.

What is the advantage of having 4 rectifiers?

Thank you all for your time and wisdom.

ESR

 

[sofaspud]

Rather than reply specifically, I'd rather point you to this application note, Introduction to Power Supplies. It should answer most of your questions, and more.

 

[!]

Yes that is a most basic unregulated linear PSU which should work fine with the kits on that site, although the particular amp you linked is not showing up at the link you gave. Be sure to pick capacitors appropriate for the DC voltage your amp will use.

The overall design topology is the same for both PSU boards you mention but the Class D PSU has a bridge rectifier which is 4 diodes together in one package instead of 4 individual diodes. The advantages of 4 individual diodes is not only does it spread the heat out more, they have a metal mounting tab/backplate so they can have heatsinks put on if/when uses they would run hot enough to need one.

Some people also feel that certain diodes in a PSU change the way an amp sounds. They "usually" feel that the bridge rectifier diodes in the 'Class D PS" on that site are typical silicon diodes (this is only an assumption since classaudio does not list the part # for that) but the MUR860 diodes (linking in the schematic on Connexelectronic's site) used on the Connexelectronic PSU sound better due to being "soft recovery" type.

 

[esreuter]

Thank you very much, both of you.

i read the TI lesson on power supplies and have learned that they are simple things to provide power to things that need it.

i never knew how much stuff in our lives ran on DC power though. very interesting.

wonderful, !, i can now understand what a bridge rectifier is. i can see the advantages you speak of, since the connex has heat sinks on the diodes.

I am wondering, about the value of capacitors and power supplies, i know to get higher rated voltage, but how does one compute what farads one needs? there must be a way so that you dont go wild and waste money but at the same time get the maximum out of your power.

any thoughts?

thank you all for your wisdom and time
ESR

 

[sofaspud]

A big advantage of the bridge rectifier configuration is that it allows the higher peak voltage of the half-wave rectifier while also providing the 120Hz ripple of a full-wave rectifier. 120Hz is easier to smooth than 60Hz - this is shown by the formula for full-wave filter capacitance:
C = 1/2.828*Vr*Rl*f
where
C = capacitance in farads
Vr = ripple % expressed as a decimal
Rl = load resistance
f = ripple frequency in Hz

 

[gootee]

Thank you very much, both of you.

i read the TI lesson on power supplies and have learned that they are simple things to provide power to things that need it.

i never knew how much stuff in our lives ran on DC power though. very interesting.

wonderful, !, i can now understand what a bridge rectifier is. i can see the advantages you speak of, since the connex has heat sinks on the diodes.

I am wondering, about the value of capacitors and power supplies, i know to get higher rated voltage, but how does one compute what farads one needs? there must be a way so that you dont go wild and waste money but at the same time get the maximum out of your power.

any thoughts?

thank you all for your wisdom and time
ESR

Total capacitance value that is needed can be calculated based on desired maximum ripple voltage amplitude and maximum load current:

Unregulated Power Supply Design

If you ever add a linear regulator after the smoothing capacitance, try to make sure that the bottom of the ripple voltage waveform cannot cause the difference between the regulator's input and output voltages to dip below the regulator's spec for dropout voltage.