• The Vendor's Bazaar forum is for commercial offers and transactions. Only unmoderated members can post here.

    diyAudio provides this forum for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members. Use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Audio SMPS units for sale

Jump to Latest
#283
Hi @Cresnet

I'm considering an SMPS supply for an AB amp that I'm building. I'm looking for around +/- 50-60V or so, a simple aux supply, soft start, overcurrent protection etc. I'm trying to size the output caps, sag on demand and so on. Can you tell me if the SMPS sees a constant load of 800mA, and is subjected to a transient of one 30Hz half sine of 20A, how much voltage sag should I expect, assuming your standard output capacitors? And if some extra capacitors were added, what would you recommend?

Which model SMPS would you recommend for this application?

Thanks!
 
#284
woodturner-fran said:
Hi @Cresnet

I'm considering an SMPS supply for an AB amp that I'm building. I'm looking for around +/- 50-60V or so, a simple aux supply, soft start, overcurrent protection etc. I'm trying to size the output caps, sag on demand and so on. Can you tell me if the SMPS sees a constant load of 800mA, and is subjected to a transient of one 30Hz half sine of 20A, how much voltage sag should I expect, assuming your standard output capacitors? And if some extra capacitors were added, what would you recommend?

Which model SMPS would you recommend for this application?

Thanks!
Click to expand...

Hi,

SMPS1K-PFCR2 & COBRA-S1 & COBRA-S2 have aux supply, soft start, and overcurrent protection.

The SMPS will start normally with any constant load up to full load at power-up.

However, SMPS1K-PFCR2 & COBRA-S1 & COBRA-S2 have a maximum of 9~10 V drop at full power.

For example, if your supply output voltage is +-50VDC maximum drop won't be higher than 10V.

I still advise you to use some extra capacitance at the output with the SMPS1K-PFCR2 if not using COBRA-S1 or COBRA-S2.

Thanks
 
#286
EUVL said:
I am a bit confused.

Do I understand correctly ?
So the output voltage in the specification refers to no-load conditions.
And at full load, it can be 10V less.
So what about load levels in between ?


Patrick
Click to expand...

Very good question.

I don't have a chart with output voltage VS load.

But I can conduct some tests when I have some time and post it here.

But let me give you an example, as below from another SMPS (Unregulated)

Thanks
 

Attachments

  • SMPS440TK4.png
    SMPS440TK4.png
    14.8 KB · Views: 170
#293
No sir, I have no plans to use any SMPS myself.
I am merely trying to understand how I should read SMPS specifications.

Let's say someone wants to use a SMPS for a Class AB amp, for example.
And the particular amplifier does not have great PSRR, any power supply modulation will affect performance.
So I think it is only reasonable for people to know what output impedance they can expect, regulated or not.

Take SMPS1k +/-55V for example.
Full load at 1200W means a touch over 10A at full load.
If the output voltage then drops by 10V, that means a PS output impedance of 1R.
Which the amplifier designer would need to know to see how he will deal with that.
Or whether he should choose some other power supply.
Or he should allow for the 10V drop and put a 45V regulator downstream.

It is not unreasonable to ask for information, don't you agree ?


Regards,
Patrick
 
You must log in or register to reply here.
Top Bottom