Voltage regulating system for electrical loads in a motor vehicle

Regulating apparatus for regulating the supply voltage of an electrical load of nominal supply voltage, the apparatus being adapted for connection to a variable value unidirectional voltage source, and comprising:

• an oscillator for generating a rectangular control signal having a cyclic ratio that varies with the value of the said unidirectional voltage when said unidirectional voltage is greater than a given threshold value;
• a first controlled interrupter connected to the oscillator and controlled by the control signal, the first controlled interrupter being connected in series with the electrical load across the said variable value unidirectional voltage source,
• wherein the apparatus further includes an inductance connected in series with the electrical load, and a second controlled interrupter arranged for connection in parallel with the series mounted electrical load and inductance;
• and
• wherein the oscillator is connected with the first and second controlled interrupters for supplying a common control signal to the first and second controlled interrupter.