Using Slightly Different Voltage Power Supplies...

[LEDAdd1ct]

I have an Aopen 4501 machine on order, used, with no power supply. Most of the websites that sell it list the correct adapter as being a power brick which supplies 20v DC at 4.5A. I have an adapter already which is rated for 19v DC at 4.74A.

20v * 4.5A = 90w

19v * 4.74A = 90w

After extensive googling, I've found two schools of thought:

1) One school of thought is that with sensitive electronics like computing equipment, even a small difference can spell trouble,
either overheating if the extra voltage has to be dealt with, or problems later on from "brownout" conditions.

2) The second school of thought is that the parts in a computer run off 12v, 5v, etc., all lower than the 20v supply. Since this is the case, there must be DC<-->DC conversion at work, and so, as long as the total power is the same, i.e., 90 watts, feeding it with 19v at 4.74A is fine.

3) Additionally, the product literature says it capable of a wide range of voltage inputs, from 12v to 20v. My guess is that if this is true, and I don't see why the OEM would lie, then I would be just fine with my 19v 4.74A power supply.

Here is the link to the specs. If you scroll just a little, you can see the rated power input range:

Link to OEM (Aopen)

---> What do you guys think? I am making a big deal out of nothing? Would my 19v 4.74 amp DC power supply be safe for continuous operation?

 

[Steve K]

I think the 19v supply should be fine. Most voltage regulators aren't exactly precise, and the 5% change from 20v to 19v is pretty minor.

OTOH, if you have misgivings... maybe just buy the official power supply??

 

[Dirtbasher]

Your main issue might be the DC plug that inserts into the device, they vary in size and inner diameter, most common is 5.5mm long with an inner pin diameter of 2.5 - 3mm

 

[LEDAdd1ct]

Thanks, guys. The plug is indeed 5.5mm by 2.5mm.

 

[LEDAdd1ct]

The manufacturer, Aopen, wrote back, and stated that a power supply of 12v to 20v DC of 90w or more would work.

 

[Dirtbasher]

The manufacturer, Aopen, wrote back, and stated that a power supply of 12v to 20v DC of 90w or more would work.

90watt is the key there, so make sure by using the calc : volts x amps to get watts
Ie 12V X 7.5A is 90 watts, haven't seen too many 12v power packs of that rating?

 

[LEDAdd1ct]

I agree, not nearly as many as the higher voltage models.

But they do exist.

 

[serkan90]

@LEDAdd1ct: I think for Aopen 4501 19V supply would be fine because the difference between 19V and 20V supplies is very less and moreover the electronic components in the machine require 12V, 5V constant supply and for this purpose they use the voltage regulators and if you will provide 20V or 19V, the output of the voltage regulator is fixed i.e. 12V or 5V. So you can use 19V supply as it hardly makes any difference.

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