Vicor Ripple Attenutation Module und Switched Power Supply

[thomaspf]

Does anyone here have any exprience in reducing the high frequency ripple on a dual rail swichted power supply with a pair of Vicor Ripple Attenuator modules. Example below.

RAM Ripple Attenuator Module / Vicor Power Filters


I am trying to avoid a heavy toroid for a power amp and this module might work to minimize the voltage ripple as well as supressing high frequency switching ripple.

Cheers

Thomas

[janneman]

Originally Posted by thomaspf

Does anyone here have any exprience in reducing the high frequency ripple on a dual rail swichted power supply with a pair of Vicor Ripple Attenuator modules. Example below.

RAM Ripple Attenuator Module / Vicor Power Filters


I am trying to avoid a heavy toroid for a power amp and this module might work to minimize the voltage ripple as well as supressing high frequency switching ripple.

Cheers

Thomas

I have used Vicor modules for power amps with and without RAM modules. But I don't have any measurements (yet) so I relied on the published performance for the ripple and noise reduction.

jan didden

[thomaspf]

That sounds like a promising start!

I am not planning to use the Vicor power modules. Do you believe they can be interfaced to a standard switched power supply. I assume the attenuation is tuned towards their specific DC-DC converters but according to the spec the attenuation is pretty broad band.

One question I am unsure about is how to connect up a pair of RAMs to a dual rail supply.

The supply I am starting with is the SMPS500R from Connex Electronic. It has a voltage ripple of about 85mV and who knows what in HF noise.

Do you think there is any chance to tame this supply to be useful as a power supply for an Class AB Mosfet amp?

Cheers

Thomas

P.S.: I grew up in Keulen and used to ride my bike to where you are located. There is a specialty beer store in Maaseik that I was a regular customer of.

[janneman]

Originally Posted by thomaspf

That sounds like a promising start!

I am not planning to use the Vicor power modules. Do you believe they can be interfaced to a standard switched power supply. I assume the attenuation is tuned towards their specific DC-DC converters but according to the spec the attenuation is pretty broad band.

One question I am unsure about is how to connect up a pair of RAMs to a dual rail supply.

The supply I am starting with is the SMPS500R from Connex Electronic. It has a voltage ripple of about 85mV and who knows what in HF noise.

Do you think there is any chance to tame this supply to be useful as a power supply for an Class AB Mosfet amp?

Cheers

Thomas

P.S.: I grew up in Keulen and used to ride my bike to where you are located. There is a specialty beer store in Maaseik that I was a regular customer of.

Well thge big question is how to wire up your RAMs to the dual supply wrt grounding. The easiest would be if you had two isolated supplies, put a RAM on each and then ground the appropriate RAM outputs to the amp star ground (RAM gnd for the pos half, RAM pos for the neg half).

With the dual supply you got, that will be a problem, because the RAM needs to be fed differential. Maybe there is something in the application area at Vicor regarding this? Or you can just send an email to Vicor support, they're quite accomodating in my experience.

Edit: The RAM is on the single ended supply of a Nemesis SE amp. I have also another amp with dual Vicors without a RAM and I can't hear any negative effects from the hf noise on the output. Which, of course, may just prove that I can't hear higher frequencies ;-)

jan

[thomaspf]

I contacted Vicor and you are right. The RAM modules can not be used with a dual rail power supply with common ground.

I guess it's back to a more traditional passive fillter. Probably some form of an LC fiter. The Connexelectronics SMPS500R switcher has a variable switching rate from 110 - 250Khz.

Any ideas or templates for how to build an effective (potentially multi pole) filter for +/-30V at ~10A that gets the voltage ripple down from the native 85mv and does not impede power delivery.

Cheers

Thomas