the device can put out around 2 amps exactly on the mark and no higher.
I need to drop it one volt to run my laptop because the original laptop is gone and I don't want to buy a new charger for it.
the charger I have runs fine and I wish to use it to run my newer laptop. but the laptop requires 18 volts DC and 1.5 amps and since I don't have a charger for it I wish to use the one I already have. if I can use some simple resistors to drop it by one volt that would be great.
I tried it before but the laptop doesn't turn on. I see the lights flicker madly when its plugged in. not a good thing. it scares me. so I want to try dropping the voltage by one volt to see if it makes a difference.
Are you sure? 3 of the 4 laptops around here have 3 conductors. There's probably an embedded controller at each end, brick and battery.
The 4th uses NiCads.
Otherwise, using diodes or an LDO regulator would be the way to go. A resistor's voltage drop will vary with the current through it so makes a poor regulator.
FWIW my 2011 Toshiba NB505 has happily charged with any generic charger I have plugged it into, at least so far.
My son has a 2012 Acer labelled one, which probably was made by the same giant OEM manufacturer, same considerations.