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Very Dangerous Chinese 5V 1A Cube USB Charger

(Reverse Engineered Schematics)

Very dangerous Chinese USB charger 5V 1A in cube shape. Called "European" but does not fit into the E (French style) socket. It has 2 boards, connected by 4-wire flat cable with a very thin insulation, despite the cable includes both primary and secondary sides. It has no fuse or fusible resistor. Insulation distance between the primary and secondary sides of the PCB is only 0.5 mm! Dodgy transformer with poor insulation. Suppression capacitor between the primary and secondary sides is not a safety Y1 type, but only an ordinary miniature 1kV type. The main transistor 13001 has no snubber network to protect it against inductive spikes from the transformer primary, so it is likely to go short. When it goes short, the transformer primary may melt (evaporate or explode), damage the insulation and possibly connect with secondary, connecting mains to the output. The output current (1A) is rectified by a 1N4148 diode that has a maximum current of 0.15A (!!!). At 0.5A load the output voltage already drops to 2.7V. The charger is not only dangerous, but also virtually useless. The plug is loose, the box may open while you unplug it. An electric shock may happen for many different reasons, as well as fire.

The dangerous Chinese Cube USB 5V 1A Charger.

2 board construction. Both boards contain both primary and secondary tracks. The components on primary and secondary side touch each other.

The isolation distance between primary (mains) and secondary (output) sides is 0.5mm at several points.

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