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Guide: plugpack selection

Discussion in 'Electronics & Electrics' started by LethalCorpse, Aug 18, 2008.

  1. OP
    OP
    LethalCorpse

    LethalCorpse Member

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    I did read your post, and the links you posted, and have already done much further research online. I've also done actual research, the kind with books and libraries and a few years in an educational institution. Refer, again, to my previous post.
     
  2. HotHed

    HotHed Member

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    Thanks so much for the guide.

    I ordered wahl clippers for the dog. One of the reviews said it had a 120-240V charger.

    It came with a 120VAC to 5VDC 100ma charger. :mad:


    I found an old nokia charger 240VAC to 5.7DC 890ma, and swapped the fittings.
    I'm hoping it does not over charge the battery. (14% higher voltage) :Paranoid:
     
  3. mikk

    mikk Member

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    Probably not a concern for a modern device.
     
  4. schmoove

    schmoove Member

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    I'm looking for a 24v 1.0a linear regulated plugpack form power adapter.
    It's to replace a suspected faulty 24v 1.0a smps power brick on a USB DAC.
    Buggered if I can find one!

    From the OP
    I can find:

    DFU240050D3030 24V 500ma AC to DC Linear Regulated Power Supply
    https://www.atbatt.com/24v-500ma-ac-to-dc-linear-regulated-power-supply-85999.asp
    not enough current

    DFU240115J0590 24V 1150mA AC to DC Linear Unregulated Power Supply
    https://www.atbatt.com/24v-1150ma-ac-to-dc-linear-unregulated-power-supply-86038.asp
    not regulated

    Am I looking for something that doesn't exist? Anybody help?

    Edit:
    scratch that - I'm an idiot - for some reason I was sure it was 1.0a but I've just double checked and it is 0.2a.
    Should be easy to find a replacement.
    Thanks!

    Edit2:
    Nope!
    I'm finding it impossible to find a regulated linear 24v dc adapter.
    12v are easy to find, but nothing above that....I have no idea why that is :(
    And the Jameco one from the link above is only 120v input :mad:
     
    Last edited: Oct 30, 2017
  5. OP
    OP
    LethalCorpse

    LethalCorpse Member

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    If it only needs 200mA, the 500mA regulated supply should be fine
     
  6. schmoove

    schmoove Member

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    It is 120v input, so won't work in my country.
     
  7. AgB deano

    AgB deano Member

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    There are plenty of high quality 24v uiniversal SMPS on the market but few have enclosures.

    So, frankly, I would use a common and well branded laptop 19.5v universal SMPS and be done with it. I'll bet you a virtual dollar it'll work fine and a lot better than a lot of other junk out there, that'll likely produce a lot more noise than your typical high quality laptop psu.
     
  8. schmoove

    schmoove Member

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    Thanks for the reply!

    I don't know that much at all about this topic so I'm following the OP and bearing in mind this:
    I'm not keen to try and run the DAC at 19.5v.

    I was looking for a linear regulated supply, as recommended in the OP.
    As a 240VAC input 24VDC linear regulated plugpack form seems to literally not exist in the entire world, I'll just go with a standard, hopefully half-decent 24VDC SMPS.
    Probably this one:
    http://www.devicemart.co.kr/1153410
     
  9. AgB deano

    AgB deano Member

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    What exact make and model is your USB DAC?
     
  10. schmoove

    schmoove Member

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    Last edited: Oct 31, 2017
  11. AgB deano

    AgB deano Member

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    Interesting read. I can see why these things gained a foothold in a niche market.

    The short and simple - that unit will be fine with a QUALITY 19/19.5v laptop SMPS to drive that FET opamp, which has an input of 4.5-24v, nominally 15v. That's all your ext psu is driving, the usb source powers the DAC and misc parts.

    As well as this, a quality laptop SMPS is going to put out a hell of a lot less noise than both a cheap linear and smps, especially the $10-listed-on-a-random-korean-website kind.

    If you want a quality universal AC 24VDC linear PSU, there are plenty out there, just need to know where to look. element 14 and farnell are a good place to start.

    Alternatively, build your own. It's not that hard, there are actually quite a few kits and tutorials out there in this age of rasberry pi and assorted mobile devices.
     
    Last edited: Oct 31, 2017
    schmoove likes this.
  12. schmoove

    schmoove Member

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    http://au.element14.com/triad-magnetics/wsu240-0500-r13/wall-mount-adaptor-ac-dc-24v-0/dp/2706411
    24v 0.5a
    How do I know if this adapter is smps or linear?
    No filter options for that on the site and I can't see it on the webpage.
    Even the datasheet doesn't specify.

    Can you give me a direct link to one? I can't find a plugpack type one.

    Audio folks sometimes use something like this:
    https://www.ebay.com/itm/STUDER900-...143668?hash=item212ca83bf4:g:IvIAAOSwRDpZm~VV
    But if I'm going to spend USD 50 I might as well buy a new DAC as the tech has moved on a bit since 2007.
     
    Last edited: Oct 31, 2017
  13. dakiller

    dakiller (Oscillating & Impeding)

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    Weigh - transformers in linear units will be heavy.
    Input voltage - 100-240v says SMPS, as a linear transformer will only have a single fixed voltage it will work at.

    Looking at that DAC, as AgB deano says, it'll be fine on a lower voltage. Heck, even 12v will be fine here.
     
    schmoove likes this.
  14. schmoove

    schmoove Member

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    Thanks for the replies, I'm learning plenty here.
    I've got a universal laptop psu here, so I guess I can try it on that then.
    One thing that I still don't get though is why would Firestone Audio make the unit 24VDC in if it will work fine on 19VDC or even 12VDC?
    From my experience most other small audio gear like this uses around 9, 12, or 14VDC.
     
  15. dakiller

    dakiller (Oscillating & Impeding)

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    Because the copied the design from someone else that had 24v, or they copied the datasheet schematic that had +/-12v for the opamp, or they plucked it out of thin air and though that will do.
     
  16. schmoove

    schmoove Member

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    Ran the USB DAC on a universal laptop PSU @ 19v for about a year, then the PSU blew.
    Was always running boiling hot. Didn't when used for a laptop.
    Why? IDK.
    Would I run this DAC on 19v again? No.
    Picked up a 24v 1.0a smps at the junk market today for $2.
    Tests at 24v and bonus it's only the exact right plug size!
    Will give it a listening test with the DAC tomorrow.
     

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