Identification 4 pins crossing High-low voltage boundry, marked ABS10, 2 pins marked + -

Question

What is the black 4 pin chip in the top left marked ABS10, beside the 15 uf cap, pray tell? It bridges the hi-lo boundary on a 3amp USB power supply.

^{simulate this circuit – Schematic created using CircuitLab}

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Edit to add...

Thinking about the circuit, it seemed that the ABS10 would have to significantly lower the voltage, as the PCB slot ends at the far side of the device. If high potential still exists there, the implementation would be violating the safety rules. Therefore the ABS10 must be some new wondrous device that makes HV safe. ({grin} Stupid me.)

I should have gone with Occam's Razor: given the source and past history of power supplies from there with UL case marking being added without certification, the design is defective. The + and - markings should have shouted "rectifier" at me, not to mention the voltage rating on the capacitor.

Answer 1

It's a bog-standard bridge rectifier. It converts the AC into (pulsating) DC which is smoothed by the cap and fed to the rest of the converter.

More specifically, it's an ABS-10 bridge rectifier, available from several manufacturers, rated for a max RMS voltage of 700V and max average forward rectified current of 0.8A.

Here's a datasheet from Multicomp.