It has a very small transformer. I have the photographs. I fit is possible, could you explain the circuitry in the charger, Would really appreciate it! Terry: most of the flyback transformers in chargers are custom built. But parts companies like Digikey sell flyback transformers, so you'd need to find what they have that would work.
Or you could wind your own, which people actually do. But really, you're generally better off buying a power supply than building one yourself. Nipun: I can take a look at your photographs and see what I can explain. Recently had one of these die. Took it apart, found C1 (4.7uf) dead, bulged/leaking.
The ye olde capacitor plague! C2 looks ok (6.8uf) but ordering new parts to see if I can get it working. Will post back when working. C1 was bulged leaking, C2 looked ok but replaced on spec. Other cct checks confirmed all was ok just replace the caps! Hello, thanks for the good article.
I have to admit I was just about to buy a 4 dollar one today but I see now that I would just be buying more landfill space. I've seen those images on the net of burned homes caused by chargers and that led me to this article. I thought I read somewhere that real Apple chargers have 10 watts and counterfeit ones have 5 watts.
Anonymous: counterfeit chargers vary in wattage. I referred to your Apple smps tear-down and also to its schematic.But i just wanted to know about the Q1 and Q2 Mosfets.Are they really IRFP250, Because i have seen them they are very big but your tear-down photographs shows some different transistors. The schematic shows a single type of ground sign for all the grounds. It would be great if you could clear my doubts.
Anonymous: you are right about the schematic. The transistors are 1HNK60 MOSFETs, not IRFP250. And yes, the grounds on the primary and secondary are isolated from each other. Thanks for clearing my doubts Ken. I'm really sorry for replying so late! This is regarding the BlackBerry(750mAh) Charger posted on March 18, 2015. I Couldn't find your e-mail id so here are the links to the photos that I have uploaded.
Let me know when you check them out and whether you need a clearer picture of any component! I took a look at your Blackberry charger photos. In the first photo, the secondary (output) is at the left. The primary (input) is at the right. You can see the flyback transformer with electrolytic filter capacitors above and below it. Wires go from the transformer to the secondary. The secondary has a filter capacitor above the USB connector and a filter inductor below.
The second photo shows most of the circuitry. The primary side is on the bottom and is separated from the secondary by a slot in the board. First, the AC is converted to DC by the bridge rectifier (ABS10). The control IC (Pow3er Integration SC1106DG) also contains the switching transistor and controls the power to the transformer. Underneath the control IC are various resistors, capacitors, and diodes.
The IC gets a feedback signal from the transformer (rather than from the secondary side). At the top, the main secondary components are the diode (S34) to convert the output to DC and the tantalum capacitor (E8) that filters the output. I have a bike light (night rider) that uses a USB charger.
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