until 1 of the 4 paralleled LEDs fails. If it fails open circuit then the other 3 pass 41mA each, until another one fails......
My thoughts exactly, but this is Made in China….all companies in China are owned by the State, and so the State can arrange for each company to benefit from high volume component production…
The Chinese state will commandere a Chinese LED foundry for a day or two, and order them to make 40mA rated LEDs in the millions, and to optimise the silicon process toward equalised Vf’s amongst the LEDs…(rather than optimising for chromaticity, etc etc), and also , they will get the foundry to add resistance into the bulk semiconductor of the LEDs, so that these leds can be paralleled.
Because the Chinese state owns all electronics companies, it can do this in high volume, and make certain companies that it owns make products with the customised leds that it has just produced in the millions.
The biggest laugh is when you see Western companies trying to copy this parallel operation, but stupidly use standard LEDs from a certain Vf batch, not knowing that even equal Vf groups of standard leds vary by up to 250mV in Vf….the Chinese ones, (from their special process), are virtually equal in Vf).
How do I know that the Chinese add resistance in to the bulk semiconductor of some of their leds so that they can be paralleled?…..well, we took apart a Chinese “72 led lamp”, and found all 72 white leds in parallel, (actually three groups of 24 leds in parallel, each group of 24 having a 10R resistor upstream of it.).
Each white led carried just 8mA….but had a Vf of 2.96V. –That proves that the Chinese added bulk semiconductor resistance to each led’s semiconductor material…because theres no way that you’d otherwise get 2.96V across even a white led that’s carrying just a puny 8mA.
Every now and again the process goes awry , and the Chinese product fails in the field, -but then all the Chinese company does is “close itself down”,and start up again under a different name, and pull in some more Western customers under the different name.
This whole thing of course, takes place with Western “middle men” overseeing it all and acting as the go-between to the western markets, and screwing their own Western companys in the process.
The East has seen that Western capitalism works to a point….but can be turned on itself, to their own advantage..The capitalistic structure makes individual's and companies operate only with self interest..so the Chinese give the Western "middle men" an "£interest", and then these western middle men go forth and help the Chinese to put their own western countrymen and companies out of business...the biggest "sucker " for this is UK.