Abstract: Provided herein are improved apparatuses and methods for protecting polarity sensitive loads in DC power circuits that include a power source, a relay coupled to the power source, and a polarity sensitive load coupled to the relay. A diode can be coupled between the power source and the relay. When the power source provides a DC voltage of a desired polarity, the diode can block a current from flowing to a coil of the relay. Consequently, the relay can provide a current path to the polarity sensitive load. When the power source provides a DC voltage of an incorrect or reverse polarity, the diode can allow a current to flow to the coil of the relay. In turn, the coil of the relay can be energized, causing the relay to disrupt the current path provided to the load, thereby protecting the polarity sensitive load from the reverse polarity condition.

Abstract: Provided herein are improved apparatuses and methods for protecting polarity sensitive loads in DC power circuits that include a power source, a relay coupled to the power source, and a polarity sensitive load coupled to the relay. A diode can be coupled between the power source and the relay. When the power source provides a DC voltage of a desired polarity, the diode can block a current from flowing to a coil of the relay. Consequently, the relay can provide a current path to the polarity sensitive load. When the power source provides a DC voltage of an incorrect or reverse polarity, the diode can allow a current to flow to the coil of the relay. In turn, the coil of the relay can be energized, causing the relay to disrupt the current path provided to the load, thereby protecting the polarity sensitive load from the reverse polarity condition.