Replacement Power Supply for Console

[Matt C]

I'm in the market for a new power supply for my console.  I need +-24VDC. I measured the actual current draw of each rail at 1.7A, I figured aiming for a new supply that can do 3A or 3.5A on each output is plenty of safety margin. Low noise and reliability are my concerns. 

It looks like Acopian and Power One (now Bel Power) are the most popular options.  I'm wondering if anyone here has experience using either of these as console power supplies. The Acopian spec sheets show a little less ripple than the Bel Power supplies, but is also twice as expensive.  From my internet browsing, it's not clear to me if I should just go ahead and get the affordable option, or if there's some reasonable justification for the high price tag on the Acopian supplies. Anyone have some insight into this?

 

[Bo Deadly]

You could make one using two SMPS stacked (neg of one connected to pos of other makes ground), chokes and small caps that would be very reliable, save and quiet.

 

[mjrippe]

I have been using Power One linear supplies and Meanwell switching supplies for many years with no problems.

 

[pucho812]

what console? what are the power supplies currently not doing? They probablly just need a referb, replace electrolytics. 
I have yet to see  an OEM supply doing bipolar 24VDC. However you can easily run 2 X 24VDC supplies to get that which was previously mentioned.

 

[Matt C]

what console? what are the power supplies currently not doing? They probablly just need a referb, replace electrolytics. 
I have yet to see  an OEM supply doing bipolar 24VDC. However you can easily run 2 X 24VDC supplies to get that which was previously mentioned.

It's a Yamaha PM2000 from the late '70s. I already recapped the supply, but the board is still a bit noisy.  I intend to do a little more troubleshooting to narrow down the issue before actually replacing the power supply, but I'm weighing my options.  It seems like doing two separate 24V supplies will be the way to go, all the dual output 24V supplies I've found don't supply enough current.

 

[Matt C]

You could make one using two SMPS stacked (neg of one connected to pos of other makes ground), chokes and small caps that would be very reliable, save and quiet.

Can you elaborate on your method for adding filtering to SMPS? When I looked into it it seemed like it was an option to put common mode chokes on the output and/or the input (the incoming 115VAC).  From what I gather, a choke at the input stops the supply from sending noise upstream on the power lines and contaminating other equipment?? Is it overkill to put chokes on the inputs AND outputs? Considering this is a one off build, and noise is a primary concern, I can handle spending a few extra bucks on a couple more chokes.

 

[Bo Deadly]

I've seen chokes on inputs (although I can't recall where). I've also heard that the output chokes don't have to be common mode because the newish SMPS transformers have super low leakage inductance. So a conventional choke could be twice the inductance for the same size / price.

I would probably design the filter(s) around what parts have the most common footprint (so that the PCB is more likely to be useful later if the particular part is no longer available) given the various current / resistance / inductance values available. Just pick a current (2x what you need maybe) and then find the largest inductance without too much series resistance. If you get into mH territory that's probably pretty good. Note that SMPS don't necessarily like a lot of capacitance on the output. They're not like smoothing caps on a rectifier circuit. The caps can be much smaller.

If you do use chokes on the inputs, I would use common mode chokes because the input is not connected to the SMPS transformer. Although I cannot help but wonder if the newish SMPS need it or not. At least it's probably not important to go nearly as low frequency as the output LC filter. You just want to get the switching noise.

 

[gar381]

It's a Yamaha PM2000 from the late '70s. I already recapped the supply, but the board is still a bit noisy.  I intend to do a little more troubleshooting to narrow down the issue before actually replacing the power supply, but I'm weighing my options.  It seems like doing two separate 24V supplies will be the way to go, all the dual output 24V supplies I've found don't supply enough current.

I have been using 3  24v power one supplies in my Sphere console project for quite some time
now and they work great as I need 3 24v rails (2 of them for split 24v and one for relay logic) !!
Get a separate supply for each rail

GARY

GARY

 

[radardoug]

It's a Yamaha PM2000 from the late '70s. I already recapped the supply, but the board is still a bit noisy.  I intend to do a little more troubleshooting to narrow down the issue before actually replacing the power supply, but I'm weighing my options.  It seems like doing two separate 24V supplies will be the way to go, all the dual output 24V supplies I've found don't supply enough current.

Have you measured any actual noise figures and compared them with the original spec? That Yamaha is probably not that quiet, in terms of todays digital noise floors. Changing power suppl;y caps will get rid of hum, but not so much high frequency noise, and then only if the caps are faulty.

 

[Matt C]

Have you measured any actual noise figures and compared them with the original spec? That Yamaha is probably not that quiet, in terms of todays digital noise floors. Changing power suppl;y caps will get rid of hum, but not so much high frequency noise, and then only if the caps are faulty.

Not yet. Before I take the plunge on a new PSU I was going to disconnect all the peripheral gear and measure the board's noise in isolation from everything else.  My only concern is whether I have test gear that is accurate enough to measure low level noise like that, but I suppose just plugging into my converters and measuring through software should be good enough?