I need an AC power supply for an analog 5 watt telephone. Are the different sizes and colors of male power jacks fixed to specific power levels as an agreed on industry standard? That is, if a male jack fits my phones' female power input, do I have a match for power needed and power supplied?
No, there is nothing even remotely standard about those damn consumer "coaxial power" connectors. Make sure that the nameplate voltage and current on the unit and the wall wart match.
--scott
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"C'est un Nagra. C'est suisse, et tres, tres precis."
No. It would be nice, but whatever standardization may exist definitely can't be counted on to keep from frying components. You should not just check specs closely, but then re-check with a DVM or VOM to be sure you're safe. Unregulated wall-wart supplies are almost uniformly over-voltage, depending upon the load of what's being powered to bring them into the right voltage range.
The jacks, by the way, are the holes; the male things are plugs.
Except when the jacks have a male pin inside a hole and the plugs, which go into the hole with the male pin, just has holes. We have gender uncertainty issues here.
And make sure the polarity is correct, also. Not clear by "AC power supply" whether you mean one that can be plugged into the wall, or whether you meant that the phone actually uses some AC voltage? Of course, if the phone uses AC, then you have no concern about polarity.
Radio Shack actually has a reasonable selection of different wall-wart power supply units, and they have a "universal" system where you can buy the coaxial connector separately. They have ~50 different plugs on a big ring at the shop where you can bring your phone and find the one that fits. (BOTH the inner pin diameter, AND the outer barrel diameter.)
if radio shack sez the unit supplies x amps and z volts then the buyer is reasonably certain this will be true? a level of maybe performance at a reasonable price?
Typically unregulated (at least the universal model), so at lower-than-spec'd current draw from the device being supplied this means that the voltage will tend to swing up. How much depends on the actual load; whether this causes a problem or not will also depend on the device being supplied.
If you're not in a rush and don't mind spending a few dollars more, you might look at the regulated wall warts available from Mouser, Digikey, etc. (RS might have such entities, but be prepared to pay way more than they're worth.) Nice clean power, held pretty close. (Of course, if your device wants AC, don't do this.)
If you do go the mail order route, the same general comments apply regarding polarity; you'll also want to get the right barrel size. Many different size steps there.
While the overwhelming majority of these things may be center pin positive _DO NOT_ make this assumption. This falls into the "double check" category if you're going to use a generic or universal replacement PS.
Particularly as many units lack reverse-polarity protection. And not only cheap gear. Give a Sony Walkman Professional reverse polarity and you're instantly in for a repair bill. Unbelievable, unforgivable but true.
"Eeyore" wrote in message news: snipped-for-privacy@REMOVETHIS.hotmail.com...
And to further muddy them - some equipment that has computing chips and audio chips (eg an effects unit) that require an AC supply will boot up fine if you use a DC supply, but will have no audio. This is because the 5 volts required for the digital stuff will be generated OK but the plus and minus supplies for the audio will not.
RS just has their wall-warts custom made by some of the usual suspects. They tend to be about average quality, which is true of just about everybody else.
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