Wall wart recommendations for use with TREAD
May 17, 2006 at 9:36 AM Post #2 of 15
Any cheap unregulated unit should work fine. They're actually better for the purpose than more expensive switching regulated designs. And among unregulated power supplies, there really isn't much differentiation. Just pick one with the output current and voltage you need.
 
May 17, 2006 at 9:49 AM Post #3 of 15
Quote:

Originally Posted by 69CamaroSS396
I'm wondering which wall warts are favored by those who use them with a TREAD. Thanks!


any unregulated ones? since it'll be filtered and regulated by the TREAD, you're good to go with any unregulated wallwart.

[size=xx-small][opened too much windows and tangent already answered, but oh well.][/size]
 
May 17, 2006 at 8:47 PM Post #6 of 15
The best and cheapest wallwarts you could get are those unregulated big bricks that used to come with old printers. Often in the 24VDC (and sometimes AC) range with a lot of current. It's worth going to flea markets from times to times.
 
May 17, 2006 at 9:32 PM Post #7 of 15
Jameco has the unregulated 24VAC @500mA for $5.69, and a 1000mA whopper for just for $8.75. They also have a 24VDC, 500mA, regulated-linear walwart at $13.75. I bought all 3, but I haven't used them yet. I got the linear DC for charging and running a battery-powered PIMETA, because Elpac has stopped production on the one recommended around here.
 
May 17, 2006 at 10:09 PM Post #9 of 15
Quote:

Originally Posted by cire
i use this one. 24vDC @ 750ma, but the one i use actually runs at 29v, which is convienient.


All unregulated wall warts have a voltage rise when unloaded. If you put a 750 mA load on that unit, it will drop to 24V. It's usually a fairly linear relation between load and voltage between. So for instance, with a 375 mA load, you'd expect the voltage to be 26.5.
 
May 18, 2006 at 12:40 AM Post #10 of 15
Quote:

Originally Posted by tangent
All unregulated wall warts have a voltage rise when unloaded. If you put a 750 mA load on that unit, it will drop to 24V. It's usually a fairly linear relation between load and voltage between. So for instance, with a 375 mA load, you'd expect the voltage to be 26.5.


no, it runs at 29v loaded by TREAD and millett. unloaded its 32v
 
May 18, 2006 at 1:42 AM Post #11 of 15
wink.gif
The 24VAC wallwarts are a good deal from digikey. I wouldn't want to use an old beat up wallwart.
 
May 18, 2006 at 3:53 AM Post #12 of 15
Quote:

Originally Posted by cire
no, it runs at 29v loaded by TREAD and millett. unloaded its 32v


Okay, so the expected voltage at half load would be 28V, then. My point is the same.
 
May 18, 2006 at 8:45 PM Post #13 of 15
As always it depends on your needs. If you want it portable to lug around, and the amp isn't some monster that consumes several hundred mA, there's no need to go overboard with a > 500mA wart. For example, a wart I use with a Pimeta (consumes a little under 80mA) is capable of about 200mA and entire wart with regulator board inside measures 3L x 2W x 1.75H" (excluding cord and plug).

On the other hand, if you're not interested in portability so much and have no plan to dedicate it permanently to a particular amp(s), look at how your Tread is configured, what it's max. current capability is. For example, if it has LM317 that's 1.5A max, BUT if you aren't going to put a big heatsink on the regulator, the realistic max is a lot lower. If your Tread can't handle 500mA, there's not much point to a wart capable of more than that, except if it'll be operating in a higher ambient temp or a static current drain at reasonably high % of the transformer rating, then the resultant heat could make it worthwhile to either choose a larger capacity transformer or drill some vent holes in the wart casing... which if you don't know the internal layout of the wart, can be risky (trying to do it blind instead of cracking open the wart).

Personally, I prefer warts that have screw-shut cases instead of welded or glued shells. That tends to make them slightly larger though.

As for specific warts, no need to be picky about brand, keeping your technical criteria in mind, and you may find there is a cost savings in adding it to some other parts order because shipping cost for a wart alone can easily be as much or more than the wart cost.
 
May 18, 2006 at 9:59 PM Post #14 of 15
Thanks again for all the replies. Since I was ordering from Mouser anyway, I opted for more of the Xicon #412-224054. 24VAC, 500ma, and it's less than $6. I was curious to see if there was any specific reason for an upgrade. Glad to know that these will do the trick and do it well.
 

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