• Disclaimer: This Vendor's Forum is a paid-for commercial area. Unlike the rest of diyAudio, the Vendor has complete control of what may or may not be posted in this forum. If you wish to discuss technical matters outside the bounds of what is permitted by the Vendor, please use the non-commercial areas of diyAudio to do so.

Switched Mode Power Supplies (SMPS)

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
A

alkasar

Member
Joined 2009
mr_push_pull said:
so it's the output capacitors that give height? based on the pics I thought it's the input ones. I could fit my (shorter) caps but I'd have to add that anti-vibration adhesive. I prefer to keep headaches to a minimum.
what voltage is the PS you have (36 mm)?
Click to expand...
Oops.. i was wrong : mine is 32mm high :guilty:

It has 40V output capacitors. These are only 25mm high. SMPS height in this case is due to mains filter capacitors and transformer.

The 300R pictured on website seems to have 63V caps.
 
O

OzMike

Member
Joined 2007
Hi Christi,

I'm very interested in using your SMPS500R (+/-50V) with my SKA-Audio GB150 Class AB amps to replace the linear PSU. However, Greg has emphasized the importance of low supply impedance and high PSRR for best performance of Class AB amps, so could you advise the supply impedance vs frequency?

I notice in the picture the pair of 6800uF (output capacitors?). Would it be possible to add a pair of 3300uF 63V locally at each amp module to lower supply impedance.

Mike
 
Frosteh

Frosteh

Member
Joined 2011
I blew a fuse...

I have an SMPS500R that I hooked up and accidentally switched the ground and neutral lines when I plugged them into my amp. Of course, my amp fried and when I fixed it and turned it on again, the fuse on the SMPS blew. Any ideas on what could be the cause? I'm nervous to plug it back in when I fix my amps in case anything else on the SMPS is busted.
 
Frosteh

Frosteh

Member
Joined 2011
No no no. Sorry, I should have been more clear. I plugged the GND wire from the SMPS into the -V terminal on the amp; consequently, I plugged the -V out from the SMPS into the GND terminal on the amp. This diagram shows what happened on the first trial. The fuse on the SMPS didn't blow on the first trial, but rather the SMPS made a strange humming sound. When I fixed the outputs to be correct for the second trial, the amps turned on for a moment, and then the fuse on the SMPS blew.

The first picture is showing what happened when the connections were incorrect. The second picture shows what happened when I fixed the connections from the first trial, and tried powering the system with the blown chip in the amp.

EDIT: Another question, what screws are the mounting holes designed for? The standoffs and screws I have don't fit so I need to get more.
 

Attachments

  • ampdead.jpg
    ampdead.jpg
    82.6 KB · Views: 323
  • fusedead.jpg
    fusedead.jpg
    81.3 KB · Views: 322
Last edited:
Frosteh

Frosteh

Member
Joined 2011
Cristi said:
I see now.
seems that one of the rail was shorted. i can fix the power supply if you can send you back. please contact me by mail for return details.
Click to expand...

Is it broken or do I just need to replace the fuse? I'd rather do that than wait another month or so for shipping across the ocean.

Also, did you see my question about the screw size for the mounting holes?

This is the fuse which blew. The other two smaller ones are fine.
temporary-10.jpg
 
Last edited:
C

Cristi

Banned
Joined 2008
connexelectronic.com
In 90% of the cases, the fuse is the last one who blows, it;s purpose is not as much to protect the smps, but as much to protect the rest of the mains circuit against the effect of a short circuit.
you can replace the fuse, then have another try. i suggest to use an incandescent light bulb instead of fuse, if the smps is damaged, the bulb will lit continuously, if not, just during turn on. if is fine, replace the fuse with a similar one, 8-10A at 250V. do not make improvisations, like wires soldered over the fuse or pcb.
 
Frosteh

Frosteh

Member
Joined 2011
Cristi said:
In 90% of the cases, the fuse is the last one who blows, it;s purpose is not as much to protect the smps, but as much to protect the rest of the mains circuit against the effect of a short circuit.
you can replace the fuse, then have another try. i suggest to use an incandescent light bulb instead of fuse, if the smps is damaged, the bulb will lit continuously, if not, just during turn on. if is fine, replace the fuse with a similar one, 8-10A at 250V. do not make improvisations, like wires soldered over the fuse or pcb.
Click to expand...

Ok. I'll try the lightbulb in the morning. Are there any other tests I can run to see if the SMPS is damaged? By the looks of it, the rest of the components are fine. I don't see any blown resistors or capacitors since there are no burn marks or discolorations on any of the other parts.
 
Last edited:
Frosteh

Frosteh

Member
Joined 2011
I just did the lightbulb test and it lit continuously. This means the SMPS is broken, correct?What do I need to do to fix it? I'm quite experienced with soldering and pcb layouts and can order replacement parts in the USA, which will be much faster and less expensive than shipping to China and back.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom