Duracell myGrid puzzles me. It's a charging system consisting of a base pad where devices with special contact pads (called Power Sleeve or Power Clip) are placed for charging.
The base pad surface is covered in parallel metal stripes connected to the power source such that even pads are positive terminals and odd pads are negative terminals. The device to charge is equipped with a matching pad that has four small edge contacts projecting downwards and aligned in star pattern such that however the device is positioned on the pad there exist at least two contacts that connect to different stripes on the base pad. This is guaranteed by following the right proportions between the stripes widths and the distances between the contacts on the device pad. So however the device is positioned on the pad it gets connected to both a positive and a negative base terminal and receives power for charging.
The latter is what puzzles me. How is such contact pad (the one of the device) designed that it allows up to three contacts to be connected to the same terminal and no matter which fourth contact is connected to the opposite terminal the device is being powered correctly regardless of how the device is positioned on the base pad?
