Quick noob question about SMPS

frasco · 4th December 2011, 08:45 AM

Can I use the following SMPS to power a hifi amp using two LM3886 chips?

120W Single Output Regulated Switching Power Supply 24V 5A Universal AC input

To clarify, can I split the output to the two chips feeding them both 24V 2.5A or do I need two SMPS's instead?

I'm planning to drive a pair of small 8 ohm 2-way speakers so the effect should be enough I think?

KatieandDad · 4th December 2011, 08:49 AM

That SMPS has a 24V input NOT 240V.

It is designed for use in a truck.

frasco · 4th December 2011, 08:53 AM

Whoops, something like this then?

Regulated Power Switching Supply AC to DC 24V 5A 120W | eBay

frasco · 4th December 2011, 08:59 AM

Quote:

Originally Posted by KatieandDad

That SMPS has a 24V input NOT 240V.

It is designed for use in a truck.

Hmm are you sure? From the link:

Quote:

Features:

Universal AC input / Full range

Th3 uN1Qu3 · 4th December 2011, 09:14 AM

Does it say anywhere about +/-24v? No it does not, it only has one single 24 volt output referenced to ground. There is no negative output and your chips need that so it's not going to work. It's also too low power for your needs, i'd suggest at least 300W.

frasco · 4th December 2011, 09:52 AM

I'm more confused now than before, thanks!

Gonna have to read up more on power supplies.

jitter · 4th December 2011, 05:44 PM

The "24 V AC input" is an error in the text.

Skip to the end of the eBay link and you'll find the specs. The input ranges from 176-264 VAC and it only has a single 24 VDC out. The second eBay link shows a similar SMPS.
Both are unsuitable.

Mooly · 4th December 2011, 06:29 PM

Is there any reason you want an SMPS rather than conventional linear type ?

frasco · 4th December 2011, 07:32 PM

The main reason is probably that I was misinformed/ignorant and thought those power supplies on Ebay would be cheaper compared to building a "normal" PSU based on a transformer.

carcass · 03:20 AM

well, according to nuuk, you are indeed not misinformed

SMPS for the Gainclone chip amp

cheers

regarding your ebay smps though, you have to be careful, since even the dual output ones rarely get the same power rating at both rails.... so try to find 2 of them (large enough that is)

4th December 2011, 08:45 AM	#1
frasco diyAudio Member Join Date: Nov 2011 Location: Finland	Quick noob question about SMPS Can I use the following SMPS to power a hifi amp using two LM3886 chips? 120W Single Output Regulated Switching Power Supply 24V 5A Universal AC input To clarify, can I split the output to the two chips feeding them both 24V 2.5A or do I need two SMPS's instead? I'm planning to drive a pair of small 8 ohm 2-way speakers so the effect should be enough I think?

4th December 2011, 09:14 AM	#5
Th3 uN1Qu3 diyAudio Member Join Date: Feb 2010 Location: Bucharest	Does it say anywhere about +/-24v? No it does not, it only has one single 24 volt output referenced to ground. There is no negative output and your chips need that so it's not going to work. It's also too low power for your needs, i'd suggest at least 300W. __________________ "Audio grade" components simply means that they failed at a more critical job.

4th December 2011, 06:29 PM	#8
Mooly diyAudio Member Join Date: Sep 2007	Is there any reason you want an SMPS rather than conventional linear type ? __________________ ------------------------------------------------------- *A simulation free zone.* *Design it, build it, test it.*

5th December 2011, 03:18 AM	#10
carcass diyAudio Member Join Date: Oct 2006	well, according to nuuk, you are indeed not misinformed SMPS for the Gainclone chip amp cheers regarding your ebay smps though, you have to be careful, since even the dual output ones rarely get the same power rating at both rails.... so try to find 2 of them (large enough that is) Last edited by carcass; 5th December 2011 at 03:20 AM.

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4th December 2011, 08:49 AM	#2
KatieandDad diyAudio Member Join Date: Nov 2011 Location: UK	That SMPS has a 24V input NOT 240V. It is designed for use in a truck.

4th December 2011, 08:53 AM	#3
frasco diyAudio Member Join Date: Nov 2011 Location: Finland	Whoops, something like this then? Regulated Power Switching Supply AC to DC 24V 5A 120W \| eBay

4th December 2011, 09:52 AM	#6
frasco diyAudio Member Join Date: Nov 2011 Location: Finland	I'm more confused now than before, thanks! Gonna have to read up more on power supplies.

4th December 2011, 05:44 PM	#7
jitter diyAudio Member Join Date: Aug 2004 Location: Eindhoven, The Netherlands	The "24 V AC input" is an error in the text. Skip to the end of the eBay link and you'll find the specs. The input ranges from 176-264 VAC and it only has a single 24 VDC out. The second eBay link shows a similar SMPS. Both are unsuitable.

4th December 2011, 07:32 PM	#9
frasco diyAudio Member Join Date: Nov 2011 Location: Finland	The main reason is probably that I was misinformed/ignorant and thought those power supplies on Ebay would be cheaper compared to building a "normal" PSU based on a transformer.

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