# Laptop power supply tinkering

Due to scrounging old office hardware, I have an older Toshiba laptop that requires 19 volts @ 6.3 amps. My bin of power supplies only contains a load of adapters supplying 19V @ 3.16A, which are enough to charge the battery but not actually run it.

It seems to me that I could tape two of these together, splice the cables, and have myself 6.32A. Or a small fire. Any informed predictions / suggestions?

(The only concern I could think of is something related to frequency, but since they’d both be fed by the same 60Hz supply, it seems like it should work no problem)

AC or DC? If DC, I see no problem. AC will require a little more work. Are the plugs polarized, one blade bigger? If so, that will make it easier. If not, you will need to set up a fool proof system of plugging them in the same way every time. Fool proof! You will then need to check the power leads. Start with one lead from one power supply. It should have zero volts to one of the leads of the other, and 36 volts to the other. Pair up the leads with zero volts between them. Pair up the remaining 2. Based on what I know about electricity, it should work. This is not something I know of being done and working.

A laptop power supply will be DC, so I can’t think of any problems, other than that the power supplies probably won’t supply the exact same voltage. Whether that’s a problem worth worrying about or not, I can’t say. That’s my informed prediction, as a sophomore EE student.

This is a very bad idea.

What you want are load sharing power supplies, and just paralleling two together doesn’t do any load sharing at all. If one voltage is just slightly higher than the other, then it will not only try to supply the entire load, but the two voltages will fight each other. Depending on how the regulators are designed, the voltage in the first supply may drop to the point where the two supplies start to do some basic load sharing, but there’s no guarantee that they’ll share it 50/50. Another possibility is that the one with the higher voltage tries to bring the voltage of the other supply up to match it, which may require a lot more than 6.3 amps if the other supply doesn’t want to cooperate.

I’m predicting a lot of smoke.

That’s my informed prediction as an EE with 23 years of experience.

Out of curiosity I have not seen any notebooks (including 17 inchers) in the last 6+ years that would require this relatively huge (for a notebook) level of DC amperage. What is the model # of this beast?