Combined heating and capacitive seat occupant sensing system

A combined heating and capacitive seat occupant sensing system comprises a common mode choke is configured so as to satisfy at least one of the following conditions: -5% ¤ [K REAL (f 1 , f 2 , T)-K REAL (f 1 , f 2 , T REF )]/K REAL (f 1 , f 2 , T REF ) ¤ 5%, for any temperature T in the range from -40°C to +150°C, where T REF = 25°C and where the function K REAL (f x , f y , T) is defined as the ratio G(f y , T)/G(f x , T), where G(f x , T) and G(f y , T) is the conductance, at temperature T, of the common mode choke at a frequency f x and f y , respectively; -3% ¤ [K IMAG (f 1 , f 2 , T)-K IMAG (f 1 , f 2 , T REF )]/K IMAG (f 1 , f 2 , T REF ) ¤ 3%, for any temperature T in the range from -40°C to +150°C, where T REF = 25°C and where the function K IMAG (f x , f y , T) is defined as the ratio L(f y , T)/L(f x , T), where L(f x , T) and L(f y , T) is the inductance, at temperature T, of the common mode choke at a frequency f x and f y , respectively; -20% ¤ [L(f 1 , f 2 , T)-L(f 1 , f 2 , T REF )]/L(f 1 , f 2 , T REF ) ¤ 20%, for any temperature T in the range from -40°C to +150°C, where T REF = 25°C and where the function L(f x , f y , T) is defined as the difference L(f y , T)-L(f x , T), where L(f x , T) and L(f y , T) is the inductance, at a temperature T, of the common mode choke at a frequency f x and f y , respectively.