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The power supply I bought has an output voltage of "15-24V". I need 19V for my laptop and I couldn't find anything where I could adjust the output voltage to a desired value (like a little screw or something).

enter image description here

Measuring the voltage gives an output voltage of 20V.

Now I am confused: shouldn't the output voltage be specified more exactly?

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closed as off-topic by Nick Alexeev Jun 10 '16 at 1:03

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  • "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." – Nick Alexeev
If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ Your imgur link complains about the wrong format what I tried to edit to add your picture. \$\endgroup\$ – placeholder Jun 9 '16 at 16:22
  • \$\begingroup\$ @placeholder, you just need to add ".jpg" to the end of the url. \$\endgroup\$ – The Photon Jun 9 '16 at 16:31
  • \$\begingroup\$ @ThePhoton Homer Simpson mode on " DOH" \$\endgroup\$ – placeholder Jun 9 '16 at 16:40
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The voltage is programmed by sense resistors in the tips. For example, see this page for some of the sense resistor values used in such Targus universal power supplies. With a little DIY you can program the output voltages as you like, e.g. see here for Kensington universal PSUs.

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    \$\begingroup\$ @EugeneSh. Hacking isn't involved. As I said, the voltage is controlled by the tips. But if you want to program it to some combination of voltage and tip not available from Targus then it is a DIY project. \$\endgroup\$ – Bill Dubuque Jun 9 '16 at 16:47
  • \$\begingroup\$ Oh, I see. Sorry. \$\endgroup\$ – Eugene Sh. Jun 9 '16 at 16:49
  • \$\begingroup\$ Thanks! So this means the tip basically adjusts the voltage to the desired value by itself? Or do the different tips that come with the adapter all provide a different output voltage so I have to choose the right tip? \$\endgroup\$ – AlphaOmega Jun 13 '16 at 7:03
  • \$\begingroup\$ @AlphaOmega When you plug the tip into the power supply it senses the resistor built into the tip, which tells it the desired voltage to output for that tip. Normally the manufacturer lists the laptops that are compatible with each tip (which means that they have both compatible voltage and compatible mating plug). \$\endgroup\$ – Bill Dubuque Jun 13 '16 at 12:39

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