His solution is to add a P channel MOSFET which only allows power to flow when the polarity of the source voltage is correct. The schematic above shows the P-FET on the high side of the circuit.

A P-Channel Power MOSFET is a type of Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) that uses holes as the primary charge carriers. Unlike its N-Channel counterpart, the P-Channel MOSFET ...

An enhancement MOSFET needs a voltage applied to a gate ... voltage is applied to the Gate compared to the Source and a P-Channel activates with a negative voltage. The High Impedance on the ...

Both MOSFET types described below can be of p- or n-type (also known as p-channel and n-channel), but n-channel devices are the most prevalent. E-MOSFETs lack a built-in channel. Instead the drain and ...