LED ( 230VAC LED household lamps )
Posted by kll on April 27 2021 18:44:02
when i build my house it was the time where it was already normal to use LED lamps ( compared to the former energy savings lamps )
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sadly in the wholesale_shop they directed us to special offer from
RACER 7W
what all failed after a year... what a perfect capitalistic engineering
ok sure we replaced them with a other brand...
now i might have more details when i tear them apart later...
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but here now it's about: today the first of the 18W long lamps outside the house failed.
a TOSHI 18W
and i wanted to know what it is made from, so they still use
* * a glas tube ( so careful when you brake it ) but as it is LED no dangerous gases ...
* * inside is a opaque plastic tube as light diffusor
* * holding a aluminum strip what is on one side like a circuit board for the electronic elements.
on begin / end is one wire soldered to the 2pin plastic end caps.
( so 230VAC in and out as the LED lamp do not use the starter circuit anymore!! )
sure i checked first google LED circuits ...
but a similar design with 60LED i not find anywhere.
what i think i see is a bridge rectifier and a elco 6.8uF 400V and that "474" resistor read 470kohm
and then 20 times ( 3 LED and one resistor "101" read 100ohm ) sorry the last resistor missing,
hmm but how wired??
if 3 LED and one resistor in serial and all that then parallel?
OR
if all 60 LED in serial, how that many/big resistors make sense?
the circuit is not good visual, also if the alu carrier is used as conductor? or only cooler?
just a first idea??
and try using math:
for white 5630 SMD LED // with 20mA (peak 60mA ) should show 3.0V .. 3.2V
from here
min 60 * 3V = 180V
max 60 * 3.2V = 192V
19 * 100 ohm = 1900 ohm
min: 0.020A * 1900 ohm = 38V
all in serial would be 218 .. 230V
a bridge rectifier of 230VAC should give 323Vpeak still 228V effective
18W / 230VAC = 78mA ( why it say/prints 36mA ) but should run 20mA ???
or if it is a half bridge? no
MB10F 1000V / 0.8A max
this detailed image of a LED ( second after rectifier/elco/resistor )
might show that there is a confusing Plus Minus and LED body cut-out/groove
and also not see 4 legs? with 2 legs might be ?newer? 5730 type
possibly i start try to desolder / take the parts of / and test / play
if it is a serial connection only one damaged part will fail all, so possibly still 59 good LED?