You need to know the current for the required 1 volt voltage drop. V=I*R. So your Resistor = 1 volt/your current...
Why are you dropping one volt?
Why are you dropping one volt?
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 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.
Find a large 3A diode,and wire in in series with the positive lead. It will drop ~0.7V. That should be close enough. (~18.3V)
My last laptop was rated for 16V,but it would run on anything in the 14-18V range.
Edit:typo
My last laptop was rated for 16V,but it would run on anything in the 14-18V range.
Edit:typo
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I actually would not bother for 1 volt. the laptop should be able it take it with no issues...it will only take the amps it needs...
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.
Use two doides in series. The theoretical forward drop of a diode is 0.6 volts but it can be anywhere from 0.4 to 0.7 volts.
Gajanan Phadte
Gajanan Phadte
Are you sure the laptop and supply are compatible?
I never really looked into it much, but I assumed the supplies were 3-conductor, with the 3rd being part of the charge management.
I never really looked into it much, but I assumed the supplies were 3-conductor, with the 3rd being part of the charge management.
sofaspud is right, many have 3 conductors so they will not work without the correct brands powersupply. The plug has a central spike and the plus and minus are the inner and outer of the barrel. Dell are infamous for this - the actual charger could be standard but for the lockout from the data line.
dell-laptops-reject-third-party-batteries-and-ac-adapterschargers-hardware-vendor-lock-in/
If this is not one of the trapped brands then a couple of 5Amp diodes in line will drop 1-1.2 v or so.
dell-laptops-reject-third-party-batteries-and-ac-adapterschargers-hardware-vendor-lock-in/
If this is not one of the trapped brands then a couple of 5Amp diodes in line will drop 1-1.2 v or so.
and you have connected the positive and negative correctly?
A new compatible power adapter cost next to nothing on ebay or Aliexpress. 10$ - 12$ for many types is normal price including freight
A new compatible power adapter cost next to nothing on ebay or Aliexpress. 10$ - 12$ for many types is normal price including freight
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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.
it is a toshiba laptop very sensitive to voltage changes in power supply sadly.
And all the chargers I find online are in the 100-200 dollar+ range
And all the chargers I find online are in the 100-200 dollar+ range
i can't find the right plug size.. mine is an odd size and it's hard to find the one that fits..
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.
My son has a 2012 Acer labelled one, which probably was made by the same giant OEM manufacturer, same considerations.
Will one of these universal laptop supplies work for you?
Universal Laptop Power Supply w/USB 9.5~22 VDC 90 Watts 120-502
Universal Laptop Power Supply w/USB 4.2~24 VDC 70 Watts 120-500
Universal Laptop Power Supply w/USB 9.5~22 VDC 90 Watts 120-502
Universal Laptop Power Supply w/USB 4.2~24 VDC 70 Watts 120-500
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