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ordering external power supply

ArmorAlley

Well-known member
This is a long shot but I'll trynonetheless. I have a nice device I'd like to use (Asante Mini EN/SC-10T) and it came with a US external power-supply.
It takes in 120VAC 60Hz 35W and outputs 12VAC 1250mA.
Does any have any good experiences with ordering a custom power-supply from China, say, or Taiwan? And, if so, would post the link in the thread please.
The ones that I have found so far on Amazon DE and AliExpress are all AC/DC adapter and I need an an AC-AC adapter.
Otherwise it is a case of scouring eBay and secondhand shops for the correct output and plug.
 

cheesestraws

Well-known member
Nearly everything that works on 12V AC will also work on 12V DC. It just means that the first stage in the box is a bridge rectifier and smoothing, rather than having that in the wall plug. This used to mean that you could just have a transformer in the wall plug, which made it simpler/cheaper; now, when everything is switch mode, it's the opposite. Doing the rectification/smoothing twice doesn't matter.

I haven't tried the Mini EN/SC, but certainly my AsanteTalk bridge was fine on 12V DC. If you're really worried, open it up and check that you have a bridge rectifier as the first or second component in from the power jack.
 

max1zzz

Well-known member
The only issue with using a DC adapter is that there is a approx 1.2V drop across a bridge rectifier (assuming it is made of standard silicon diodes) so you are going to have a marginally low input voltage. It's not a issue on most devices but can occasionally be
 

cheesestraws

Well-known member
you are going to have a marginally low input voltage

Wouldn't you have that anyway, though, even with the AC adapter? The voltage drop across the diodes will remain regardless of whether its input signal is varying or not? Am I missing something?
 

max1zzz

Well-known member
That's true, I had in my head that there was two bridges so double the voltage drop, but of course in a switchmode supple the voltage is regulated to be 12V after the bridge in the adapter so that isn't a issue.

However a 12V ac adapter will actually have a peak voltage is somewhere around 17V, so after rectification and smoothing will be somewhere in the 15-16v range. presumabley the device than has some form of regulator to bring this down to 12v, given that you are now feeding a regualyed 12V before the bridge you will get a slightly lower voltage after the bridge
 

chelseayr

Well-known member
might be or not be much help but a cursory recheck of one random electronic distributor for north america shows that a hammond manufacturing and triad magnetics brands both sells ac-ac wall warts (I forgot the name of any europe distributors atm to recheck if these would be world brands)
 

ArmorAlley

Well-known member
I haven't tried the Mini EN/SC, but certainly my AsanteTalk bridge was fine on 12V DC. If you're really worried, open it up and check that you have a bridge rectifier as the first or second component in from the power jack.
I don't what I'd be looking at. If I upload a high-res. picture of the board, would it be obvious to all?
If AC & DC don't really matter here, would something like this be suitable?
On that note, I do have an external power supply from an expired IcyBox that is 12.0V, 2000mA . Would 2000mA be too much, do you think?
might be or not be much help but a cursory recheck of one random electronic distributor for north america shows that a hammond manufacturing and triad magnetics brands both sells ac-ac wall warts (I forgot the name of any europe distributors atm to recheck if these would be world brands)
As long as they are 100-240V, this is fine by me for I can easily use a US-2-pin-to-standard-European-2-pin adapter. I'll have a look though.
 
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cheesestraws

Well-known member
If I upload a high-res. picture of the board, would it be obvious to all?

We can certainly have a look!

Would 2000mA be too much, do you think?

That's the maximum current that the supply can provide, not the amount it will force through. You're generally fine to use a higher-rated PSU (in the current department) with a lower-rated device, the device just won't pull the extra current that would be available to it. That's probably the one I'd try to start with, if it's handy :).
 

mg.man

Well-known member
I have an AsanteTalk, which I recently (finally) picked up when visiting my 'folks in the US. It too had a 12VAC adapter, but being 120v only, I left it behind. I managed to find a UK 12VAC wall wart after a bit of eBay surfing - seems to be just fine.

A bit of Google'ing on the Mini EN/SC revealed this pic...
Screenshot_20210927-091955_Chrome.jpg
...and, specifically, this...
20210927_092646.jpg

So... I believe yours will certainly be OK with 12VDC. I'll double-check mine, but I don't believe it had the "/DC" part...
 

cheesestraws

Well-known member
As long as they are 100-240V, this is fine by me for I can easily use a US-2-pin-to-standard-European-2-pin adapter. I'll have a look though.

AC wall PSUs are very unlikely to be multi-voltage unless they have a switch on them: the techniques that enable that for AC/DC converters are basically closed off to them.

(Sorry for double post, mind wibbled)
 

trag

Well-known member
AC/AC adapter on Amazon. I've bought one (for another piece of equipment, but not tested it yet. Some complaints of buzzing in the reviews)

https://www.amazon.com/gp/product/B06XRMT2W5

It is incredibly annoying that when one specifies an AC to AC adapter in a search, one gets a bunch of AC to DC adapters are results. Stupid search engines.

If the result of the above discussion is that a DC adapter would be better and this one is 120/240:

https://www.amazon.com/gp/product/B01GEA8PQA

I'm not sure what connector you have on the Asante. This one comes with the fairly common 5.5 X 2.1, although I think 5.5 X 2.5 maybe a little more common.

In case you need to build a 5.5 X 2.5 end for the above AC-AC adapter:

https://www.amazon.com/gp/product/B07K4XLFQS/
 
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cheesestraws

Well-known member
AC/AC adapter on Amazon. I've bought one (for another piece of equipment, but not tested it yet. Some complaints of buzzing in the reviews)

Doesn't show input voltage; but since it specifies 60Hz I bet it's also 120V only. So not suitable for OP :(
 

trag

Well-known member
Doesn't show input voltage; but since it specifies 60Hz I bet it's also 120V only. So not suitable for OP :(

Ah, I missed that detail. Skimming. I think it's a simple transformer, so if it works with 240, you'd probably get 24VAC out of it.

Still, the link might lead to the needed item. The tough part seems to be getting out of the realm where the search engines just want to show you DC adapters.
 
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