(US5821634-A)      The electrical circuit comprises a first branch or sub-circuit including the battery (5), an alternator (2) to be driven by the vehicle's engine or transmission and for recharging the battery, a starter motor (1) deriving electrical power from the battery and for initiating engine operation, and one or more electrical components relatively insensitive to voltages somewhat higher than the battery's nominal output voltage. The electrical circuit also includes a second branch or sub-circuit including one or more supply-voltage-sensitive electrical components (e.g. lighting units) and connected to the first branch via a diode (10) providing a constant voltage drop.    Two or more reduced voltages supplies can be provided by a corresponding number of diodes deriving their input from the main voltage supply line of the alternator or battery, each diode providing an output to a reduced voltage supply line. Pref. a switch is provided in parallel with the or each diode providing the voltage drop to avoid heat creation from the diode(s) when the engine is not running. The switch can be open whilst the engine is running so that the alternator's internal fan cools the diode(s).    USE/ADVANTAGE -   For cars, commercial vehicles and tractors. Maximizes battery recharging voltage whilst restricting voltage to lighting and/or other voltage sensitive circuit(s).    (GB2305791-B)      The electrical circuit comprises a first branch or sub-circuit including the battery (5), an alternator (2) to be driven by the vehicle's engine or transmission and for recharging the battery, a starter motor (1) deriving electrical power from the battery and for initiating engine operation, and one or more electrical components relatively insensitive to voltages somewhat higher than the battery's nominal output voltage. The electrical circuit also includes a second branch or sub-circuit including one or more supply-voltage-sensitive electrical components (e.g. lighting units) and connected to the first branch via a diode (10) providing a constant voltage drop.    Two or more reduced voltages supplies can be provided by a corresponding number of diodes deriving their input from the main voltage supply line of the alternator or battery, each diode providing an output to a reduced voltage supply line. Pref. a switch is provided in parallel with the or each diode providing the voltage drop to avoid heat creation from the diode(s) when the engine is not running. The switch can be open whilst the engine is running so that the alternator's internal fan cools the diode(s).    USE/ADVANTAGE -   For cars, commercial vehicles and tractors. Maximizes battery recharging voltage whilst restricting voltage to lighting and/or other voltage sensitive circuit(s).