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Hi..
I`m trying to build a LED in to a E27 220V. housing. My big Q is, What do I need to drop the current to 12V. the LED is using 1,3Watt ?
and the 220V. is AC, and I need 12V.DC
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You have posted pointers to your private hard drive. We cannot retrieve them.
Look inside the bulb for a little transformer. There may be one 220/18 transformer there. Or else the circuit wouldn't work (I think...). If there isn't, I don't know how it works..
This light bulb is designed to work directly from 220V?
Very strange, I don't know how it works then =P.
Maybe someone with more knowledge can help you on this =)
I think you should read up above (caster.cp's post regarding the PT4115). The LED board is a low voltage buck converter. The S489A would be a schottkey diode. The IKEA housing is taken from a CFL; the OP seems to want to make a converter to sit in the IKEA CFL housing to make 12VDC to power the LED converter board.The IKEA led light that you took apart probably uses a capacitor for current limiting. It would have to be a 400 V capacitor and I can't see it in the pictures, but I can't see how else it would work. It could be inside the screw part of the light.
The component labeled S489A is a voltage supressor, which is really a high voltage zener diode.
While I'm yet to use one of these converters (I just ordered a couple so I'll see if I can have any better luck), I can imagine these spikes can be removed with a well placed snubber (e.g. on the primary coil - possibly with a flyback diode & RC or C+Zener). I've also seen a series resistor placed on the controller VCC transformer winding, probably to reduce the coupled spike you mentioned.Little flyback transformers like you are looking at on the FSQ0170RNA data sheet are extremely difficult to get right, and make for a lot more complication. I have tried and failed to wind them correctly. The problem getting the stray inductance low enough. As the current in the primary coil is interrupted, any stray inductance in the secondary will cause a voltage spike. If there is also stray inductance in the primary, that is at all linked to the auxiliary winding, there will be a big spike on the auxiliary winding. This means the auxiliary voltage rises too high and shuts down the FSQ0170RNA.