Small Tablet DC converter horribly inefficent?
Small Tablet DC converter horribly inefficent?
(OP)
Greetings,
I'm a mechanical guy so I wanted to make sure I'm understanding this right.
We are going to start using tablets as scanning stations to record job costing, inventory.etc (why tablets? I don't know, not my decision....)
Anyway, there will be quite a number of them which will never go to sleep. So I was having a look at the power consumption and was a little taken back by the inefficiency of what I found.
The DC converter/charger reads:
INPUT: 100-240V 0.3A
OUTPUT:5.35V 2A
So if the wall is 110V, then 110V X 0.3A = 33W "sucked from the wall" (the number used to figure the cost of powering the tablet)
When only 5.35V X 2A = 10.7W actually used by the tablet...? That's a 68% loss !?
Is this correct? I know the converter puts off heat but I didn't figure it was this much.
Thanks,
VS
I'm a mechanical guy so I wanted to make sure I'm understanding this right.
We are going to start using tablets as scanning stations to record job costing, inventory.etc (why tablets? I don't know, not my decision....)
Anyway, there will be quite a number of them which will never go to sleep. So I was having a look at the power consumption and was a little taken back by the inefficiency of what I found.
The DC converter/charger reads:
INPUT: 100-240V 0.3A
OUTPUT:5.35V 2A
So if the wall is 110V, then 110V X 0.3A = 33W "sucked from the wall" (the number used to figure the cost of powering the tablet)
When only 5.35V X 2A = 10.7W actually used by the tablet...? That's a 68% loss !?
Is this correct? I know the converter puts off heat but I didn't figure it was this much.
Thanks,
VS
RE: Small Tablet DC converter horribly inefficent?
RE: Small Tablet DC converter horribly inefficent?
Probably several such explanations all combined, including generous rounding up on the "0.3A".
RE: Small Tablet DC converter horribly inefficent?
Even if they are peak values, the ratio is still over 3:1. (3 watts consumed by the converter for every 1 watt consumed by the tablet). I assume the consumption ratio is linear?
So even if it is consuming only half of the peak value, it is still 3:1 ?
BTW, this is an el-cheapo model.
RE: Small Tablet DC converter horribly inefficent?
Other advice: at low power levels, you should abandon the ratios and percentages, and just focus on the watts. By way of example, if something was using a nanowatt, would you worry about it if it was only 1% efficient?
RE: Small Tablet DC converter horribly inefficent?
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RE: Small Tablet DC converter horribly inefficent?
RE: Small Tablet DC converter horribly inefficent?
Z
RE: Small Tablet DC converter horribly inefficent?
So, if it has shoddy workmanship later in life, they'll keep selling it?
TTFN

FAQ731-376: Eng-Tips.com Forum Policies
Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers
Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
RE: Small Tablet DC converter horribly inefficent?