Is it possible to make from 24 Volts - 19.5?

Question

Batteries

Good afternoon. Guys, is it possible to somehow make a 24 Volt PSU - 19.5 Volt PSU?
I can't find anything useful on the web.
There is a laptop, it needs a charge of 19.5. There is only a 24 Volt PSU (from an old printer). There is no desire to buy, since it is generally not known what is with the laptop. We need such a block in order to find out whether it turns on or not =)
And if you connect something to a 24 Volt PSU that takes 4.5 Volts, will it work? =)

Answer 1

there is a simple, but "wrong" way - take lm'ku to assemble a linear stabilizer - the excess voltage will go into heat,
there is a second way to disassemble the power supply unit, look at the circuit, find the circuit responsible for feedback and modify it by replacing the resistor / zener diode

Answer 2

You need this device
. On the one hand, you need to connect your PSU to it, and on the other, your laptop. Only now the output voltage will have to be adjusted by a voltmeter.

Answer 3

To begin with, announce the full characteristics of the printer's power supply (you voiced 24V, voice the maximum current), then the same for the laptop power supply.
Most likely you will not get the required power from the printer's power supply.
Here, for example, I have before my eyes a power supply from Canon - 24V, 0.7A.
From it you can get about 0.85A at 19.5A - this may not be enough for a laptop.

Answer 4

Если блок разбирается - то проще в нем перепаять 1 резистор(для стандартной схемотехники импульсных БП) - впаять подстроечный и настроить по вольтметру.