Thread: Adjusting the targus pa350 universal DC Power Supply

Hi I found this thread when I was looking for information on how to set the output voltage on my recently acquired (for free) PA350. I found some other information on the web and did some testing and came up with the following. This includes data from my own testing and a few posts I've copied from elsewhere to consolidate the information here.

I hope this is useful to somebody.

Code:

Setting the output voltage of a Targus PA350:
--------------------------------------------

The following data comes from testing of my PA350.
The back of my unit is labeled with: 
    "PA350(Ver. 2.0) E0801"

Looking at the plug on the end of the cord:

+--------------\
|               \
| 1   2   3   4  |
| ?   +   -  Set |
|               /
+--------------/
1 - Red    - Unknown purpose
  - Maybe current limit. Connected internally to something.
    Setting resistors to pin 2 or 3 has no effect on output voltage.
    On my one tip (#24) this is not connected.
2 - Yellow - Output Positive
3 - Shield - Output Negative
4 - Grey   - Voltage Set - See resistor table below.

The output voltage can be set by placing a single resistor between the 
Grey wire (pin 4) and either the negative or positive output wires as
shown below. I got this data by testing my unit with an assortment
of resistors (most were 5%, but some were 1%).

Output    Grey to   Grey to 
Voltage   Negative  Positive
 
 2.8        2.2K *
 3.3        2.7K
 5.1        4.75K
 8.0       10K
 9.7       15K
11.7       27K
12.3       33K
13.3       47K
13.7       56K
14.0       68K 
14.3       82K
14.7      100K
14.9      120K
15.1      150K
15.4      220K
15.7      330K
15.8      560K
16.0        1.0M
16.1        3.3M
16.1      open       open
16.2                   3.3M
16.5                   1.0M
16.8                 560K
17.3                 330K
17.9                 220K
18.9                 150K
19.6                 122K  (Resistor in #24 tip)
19.7                 120K
20.7                 100K
22.0                  82K
23.8                  68K
26.4                  56K **

* - The output went to 2.8V, and it seems to work, but the pilot light
    went out with this resistor. This is less than the unit's 3.0V minumum
    rated output voltage.
**- With a resistor less than 68K from grey to positive the unit would
    shut down and set its output voltage to about 2.0V. It is necessary
    to remove the input power to get it to reset. With a 56K it would
    shut down when the resistor was applied, but would work when the 
    power was re-applied. I did not try it under load with this resistor
    so I do not know what would happen in that case. This is beyond its rated
    output of 24V.

================================================== =========
Targus Power Tips voltage by Tip Number
- From a posting at 1-script.com by Barry Watzman

1 - +16.00 volts
3 - +18.00 volts
4 - +12.00 volts
6 - +15.00 volts
7 - +16.50 volts
8 - + 8.40 volts
5 - -12.00 volts (tip negative)
10 - + 2.95 volts
11 - + 6.00 volts
12 - +10.00 volts
15 - -10.60 volts (tip negative)
16 - + 5.50 volts (wide variation)
17 - + 8.50 volts
18 - + 9.40 volts (wide variation)
19 - +16.60 volts
20 - +13.00 volts
21 - +19.00 volts
24 - +19.55 volts
25 - +18.25 volts
26 - +19.50 volts
27 - +15.00 volts
28 - +22.00 volts
34 - + 7.00 volts
36 - +18.26 volts
38 - +24.00 volts
44 - +18.90 volts
47 - +13.00 volts
48 - +18.20 volts
57 - + 4.10 volts (wide variation)
58 - +20.00 volts
74 - +16.00 volts (wide variation)

================================================== ========
Posting from somewhere else (I didn't record the specifics):

Tip #24 [with one caveat, see below] will power the Toshiba Satellite
A105 (nominally the A105-S2712 takes 19 volts at up to 3.42 amps).

This also suggests that tip #24 will work with the A80, A85, L10, L15,
L20, L25, M30X, M35X, M40-S312TD, M45-S165 , M45-S165X, M55-S139,
M55-S139X, Tecra L2 and Tecra M2, since they all use the same Toshiba AC
power supply (PA3467U). [and it is therefore very likely that it will
work with additional models that use a different power supply but the
same voltage]

The measured voltage under an admittedly low dummy load (a 100 ohm
10-watt resistor) was 19.2 to 19.3 volts, 1% to 2% high and well within
any reasonable tolerance. The voltage would probably drop a tad under
the much larger full load of the laptop, but a 100 ohm load will draw
200ma, which should be enough to bring the power supply into proper full
regulation mode. [And if anyone is wondering, yes, after my testing I
actually did run the laptop itself from the #24 tip with no problems,
but I cannot easily measure the voltage while the laptop is running.]

================================================== ========
Posting from somewhere else (I didn't record the specifics):

I set the output voltage (which is adjustable from 3- 24V) with a 27k
resistor across the sense wires. (This is between the grey and the ground to
get 12.1 volts) When I cut off the end there are 4 wires in the cable.
A thick yellow one, a thin red one, a thin grey one and a ground (shield).