Wall Warts

Reusing "Wall Warts"

Advances in consumer electronics such as surface mount technology have reduced the ability of hobbyists to repair their own electronics and salvage components from dead appliances. One bright spot has been the proliferation of wall warts, those generally ugly sealed rectangular power supplies that usually outlive whatever appliance they originally powered.

Collecting a supply of these is handy, both as replacements for ones that have prematurely died, and for powering projects.

There dosn't appear to be any standardization of the connectors used, I collected the ones I had and came up with the following (all are 120 VAC in):

Volts	Volts	Polarity	Length	OD	ID	Brand
(Label)	(Open Curcuit)	(Inner)	(mm)	(mm)	(mm)
12	18.2	"+"	12.5	5.5	2	Action
4.5	5.4	"-"	9	5.6	2	Sony
9	dead		(3.5mm	mono	audio)	Atari
18	20	"+"	9.5	5.5	2	Realistic
12	dead	"+"	11.5	5.5	2	NAP
12	17.3	"-"	10	5.5	2	Panasonic
12	16.4	"+"	9.5	5.5	2	Kraco
18	21					Realistic
3.3	7.8	AC				Texas Inst.
12	16.7	"+"	12	5.5	2	Youwon
11.5	15.7	"+"	10.5	5.5	2	Databyte
9	9.1	"+"	10.5	5.5	2	Bondwell
3	3.9	(2.5mm	mono	audio)		Archer

	Multi-	Adapters
6	10.4					Vanco
7.5	13.2					"
9	15.9					"

3	3.5	either	14	5	2	Vanco
4.5	5.1	either	14	5.5	2.5	"
6	6.6	either	(2.5 mono	audio)		"
			(3.5 mono	audio)		"

Conclusions:

The most typical connector found is a hollow cylinder - Inner surface positive, 5.5 mm OD, 2.0 mm ID.
Length isn't generally critical, 10.5mm is recommended
Don't expect the actual output voltage to be close to whatever is on the label.
Don't expect nice sine waves from AC outputs, The transformer core may be designed to saturate in normal operation..
Don't assume a full wave rectification of the output, particularly with battery chargers..

"Inside a Power-Cube Transformer"
Troubleshooting and Repair of AC Adapters, Power Supplies, and Battery Packs

Old Modular Computer Power Supplies

Looking through some catalogs, I noticed that several old computer power supply bricks used a 5 pin DIN connector with the following outputs:

pin 1 +5vdc
pin 2 +12vdc
pin 3 grd
pin 4 -12vdc
pin 5 common

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