hifi engine

Oh boy, Ohms Law, Asian style..

It's no wonder that products from China, among other Asian countries have quality issues.
They cannot understand even basic electronic formulas.
"rough estimate" is hardly the professional way to go here.

Listed on a package is one product's specifications..of a replacement lamp.
"6 volt + 0.13 amps = 0.8 watts"
That's what it says.

Now OHMS LAW, the time-tested and accurate calculation states:
P=I x E *or* 6 volts at 0.13 amps = 0.78 watts.

Now mind you, the difference is a mere .02 watts off - BUT - is it SO hard to conform to stating accuracy and providing the Ohms Law figure?

This "rounding off" of electrical specifications surely isn't news, nor is inflated specifications, but if everything is so casually specified, it's no wonder there are issues.

If the mis-specification policy is widespread, cannot it also be a safety concern?
Just like lead in foods, tasty, yum.
They're not worried, they already got your money, you got their crap.

Customer relations?
Pray for rain, you've got a better chance of satisfaction.

Re: Oh boy, Ohms Law, Asian style..

The practice of 'rounding up' or 'down' in electrical calculations,is widespread, and accepted as norm . This practice exists elsewhere also.The general rule seems to be anything above 0.6 is rounded up, and anything below is rounded down, for all parameters.The chinese manufacturers, probably realise that Joe public, knows nothing about mathematical calculations,and so produces a dumbed down version of figures that they can understand ie: 60 watts, 100 watts, 7 watts 15 watts etc. What I find more puzzling, is why, when ring main was being installed everywhere, did they decide that 13 amp fuses would be installed?? why not round it up to 15 amp or down to 12amp. Neither means anything to Joe public, because if a fuse blows, they will insert any value fuse to get their kettle working etc.
there is only one word to describe it... DAFT.

Re: Oh boy, Ohms Law, Asian style..

LOL is quite correct, thats what I did,..heartily. A difference of 0,02 Watt is really quite negligible, local power (I mean MAINS POWER) variations and internal Power Supply variations will make a meaningful calculation to the 2nd decimal impossible. Also, spare parts are listed by the nearest standard value, and that happens to be 0,8 W, followed by 1 W, etc.
best regards

Re: Oh boy, Ohms Law, Asian style..

Since the source voltage of most items that use lamps is not regulated or accurate, listing a "precise" wattage would be meaningless.

Re: Oh boy, Ohms Law, Asian style..

FWIW it's not even Ohms law, P=IV is derived from Joule's first law ;) I'd have got a smack around the back of the head at school for attributing it to Ohm. 1 Watt = 1 Joule per second boy! Smack.

I'm not sure the specs are that far out anyway? They are basically saying use a 6V, 0.8W bulb. They could have stated current as 0.1333333333333333333333333333333333 amps, but rounding it to 2 decimal places seems fair enough for a bulb :) Not sure about the + sign instead of x, maybe something was lost in translation? My Mandarin is none existent - we were taught Latin and Classics at our state comp (!) Ars longa, vita brevis.