DC Mains filter to remove buzzing trafos

[rhythmsandy]

Im thinking to use the LC Audio DC filter
http://www.diyaudio.com/forums/atta...s-what-right-main-dc-filter-10-variations.pdf

but my requirement will go till 3.3KVA so do you recommend any other design or LC audio is fine? I believe we need to change the Zener in the above LC Audio circuit. Please recommend me im listening more to the trafo buzz than the audio itself...

 

[Destroyer OS]

Have you made sure your transformer and parts aren't loose?

 

[john_tracy]

Humbuster

I received this circuit from James Bongerno (sp?). I built the circuit but never tried it.

 

[AndrewT]

You have little hope of getting the capacitors to pass the operating current of a 3.3KVA (?) transformer and for the diodes to never pass any of that operating current.
Zener ! What Zener?

Did you mean to type kVA (kilo Volt Ampere) rather than KVA (Kelvin Volt Ampere)?

 

[rhythmsandy]

You have little hope of getting the capacitors to pass the operating current of a 3.3KVA (?) transformer and for the diodes to never pass any of that operating current.
Zener ! What Zener?

Did you mean to type kVA (kilo Volt Ampere) rather than KVA (Kelvin Volt Ampere)?

kVA (kilo Volt Ampere)

 

[mlloyd1]

are you sure the posted circuit blocks DC from getting to the transformer?
i have doubts about this circuit's effectiveness ...

mlloyd1

 

[AndrewT]

are you sure the posted circuit blocks DC from getting to the transformer?
i have doubts about this circuit's effectiveness ...

mlloyd1

Post3 is NOT a DC blocking capacitor implementation.

 

[AndrewT]

kVA (kilo Volt Ampere)

Did forget about the Zener question?
What Zener?

Have you woprked out what the operating current would be a for a 3.3kVA transformer yet?

And would that be for a resistive load only, or for a capacitor input load?

 

[jvhb]

I believe the LC audio DC mains filter follows the same principle as the Rod Elliott design (attached). This seems to be the best method for filtering small DC levels, and is very easy to make. Elliott shows how to calculate caps and diode values for given VA: Mains DC and Transformers

And happy new year!

 

[rhythmsandy]

well lets consider that the above circuit is good enough but the problem is very much evident with bigger transformers like 1.2kVA or 2kVA or even 3.3kVA which is observed in high power multi channel amplifiers. What has to be done for the above circuit to get operated even at 4kVA..! so that we can confidently run at 2.4kVA or 3.3kVA.

What is the limiting factor for upto 700VA for the above circuit? Diodes are 3Amps rated so is that why? or not only that the capacitors to be rated even for higher current and voltages?

 

[AndrewT]

well lets consider that the above circuit is good enough but the problem is very much evident with bigger transformers like 1.2kVA or 2kVA or even 3.3kVA which is observed in high power multi channel amplifiers. What has to be done for the above circuit to get operated even at 4kVA..! so that we can confidently run at 2.4kVA or 3.3kVA.

What is the limiting factor for upto 700VA for the above circuit? Diodes are 3Amps rated so is that why? or not only that the capacitors to be rated even for higher current and voltages?

Have you worked out what the operating current would be a for a 3.3kVA transformer yet?

And would that be for a resistive load only, or for a capacitor input load?

 

[rhythmsandy]

Its 14.34 Amperes.

 

[AndrewT]

is that into a resistor load?
or
feeding into a capacitor input filter after the bridge rectifier?