Wall Wart voltages.

[roughshawd]

Yes, another idiotic inception....

I would rather be interested in some means by which I could drive a significant amount of devices using a single plug, but, nature does not draw in straight lines. So, when one is to replace a wall wart, and the box full of them does not contain the correct voltage (singular as it would be in a box of plurality) most know that the proper voltage is a necessity, and the exact replacement is necessary in some cases. So I was wondering as I thumbed throu the singular options, what would a major corporation that creates special devices, use a strange voltage to power one of their most desired products? What I me aan is there a specialized set of circuits that work best with a special voltage, such as 3.3v 5v Arduino, and 13v fan motors? Why 13.8v exactly??!!!?

 

[Minder]

Fan motors do not require precise powering, such as regulated SMPS.
e.g. automotive battery power is around the 12vdc, but the alternator puts out 14.5 with engine running.
This applies in general to motors and most magnetic devises such as relays. and contactor coils.
For such devices, you are better off with simple rugged linear (transformer/rectifier/capacitor) supplies.

 

[Martaine2005]

As above, but adding battery operated items, they can stipulate 9V, 9.6V or 10V. But batteries run down!. Therefore, the item (radio for example) will still work down to 7.2V for example or lower.
I have network equipment that requires 15V but works 24/7 on 12V.

 

[kellys_eye]

Find an old laptop PSU and get a buck-boost converter module. Along with a selection of common 'barrel' connectors you will always be able to deliver the voltage and current you need.

I have a large box of wall warts that have been sat doing 'nothing' for years but the laptop/converter jobbie I use gets daily use.

 

[Bluejets]

Arduino (and any microcontroller) will require fairly precise voltages.
There are exceptions in that the range can be from around 2.5 to 5.5v but it is not considered the norm as other details must then be considered.
Standard Arduino would be 3.3v or 5v however there too it depends.
By feeding the raw input they can accept up to 12v and the boards will look after themselves via an on board regulator.
All-be-it of low power ability.

Best approach is for you to look at adjustable or fixed buck/boost converters, many types available.
Whether it's worth the extra or not is completely down to design requirements of each application.

I'd say offhand, you worry about nothing, just a storm in a tea cup.
Walwarts of the correct size for each application are not all that expensive.
If you have a specific one for your current application, fine.
If not, go buy one.
If you insist or have the need, stock up on some variety of buck/boost converters.
Chances are it'll never be the right one anyhow.

 

[roughshawd]

So bucking and converting should be my focus with stabile psu's for the everyday test scenarios with devices which use ac- dc, dc-dc, and dc-ac, and I shouldn't worry so much about the actual requirements with exception to thpe ones that stipulate a special application.
My take then...match the voltage, the impedance, and make sure there are enough amps. ! I am just skipping off the atmosphere now, bouncing on somekind of marshmallow brain fog which does work, given half a chance... Thanks... RIP sailors. It's pearl harbor day.

 

[davenn]

Why 13.8v exactly??!!!?

that has long been used for transceiver radios, particularly amateur and CB. Was selected mostly because of the mobile operation of
that gear and that the charging voltage for a car battery is about 13.8V
The transceivers will operate happily from between 11 and 14.5V

 

[roughshawd]

And yes, the ones I received from the big bad communications business along with the antenna business on the wild wolly and sometimes Webby http sales sites are working just fine!! But I was seriously considering building one.