Protection of polarity-sensitive components connected in parallel with a direct current motor or inductor

A circuit for protecting polarity-sensitive components operating from a current source of direct current, said current source having a nominally positive terminal and a nominally negative terminal, said circuit comprising:

• an inductor having a positive terminal and a negative terminal for receiving direct current from the current source,
• a protection diode coupled parallel with the positive and negative terminals of the inductor in a reverse bias configuration,
• at least one polarity-sensitive component coupled in parallel with the protection diode and the inductor, and
• a polarity protection transistor coupled in series with the inductor between the nominally negative current source terminal and the negative inductor terminal of the current source.

A method for protecting polarity-sensitive components operating from a current source of direct current, said current source having a nominally positive terminal and a nominally negative terminal, said method comprising the steps of:

• providing a direct current motor having a positive terminal and a negative terminal for receiving direct current from the current source,
• coupling a protection diode in parallel with the positive and negative terminals of the motor in a reverse bias configuration,
• coupling at least one polarity-sensitive component in parallel with the protection diode and the direct current motor, and
• coupling a polarity protection transistor in series with the direct current motor between the nominally positive terminal and the nominally negative terminal of the current source.