Control circuit for predominantly inductive loads in particular electroinjectors

In a combination of a control circuit (100) and a predominantly inductive load said control circuit being for supplying said load with current (Ii) having a high-amplitude portion with a rapid leading edge and a lower-amplitude portion said circuit (100), the improved combination comprising:

• first and second input terminals (102, 103) for connection to a voltage source (B);
• an energy storage circuit (106) connected between said first and second input terminals and comprising an inductive element (Li) of said load and a capacitive element (Ci);
• a first controlled switch element (SWi) connected between said inductive element and a reference line (105) for enabling selective charging of said inductive element;
• a second controlled switch element (SWR) connected for enabling rapid discharge of said capacitive element into said load;
• a control unit (12) for generating control signals (s.sub.i, s.sub.1) respectively for said first and second switch elements (SWi, SWR);
• means (12) for closing said first and second switch elements (SWi, SWR) when said capacitive element (Ci) is charged, and rapidly discharging said capacitive element into said load (Li);
• means for consecutively opening and closing said first switch element (SWi) when said second switch element (SWR) is closed, and producing small current pulses in said load with no energy transfer between said load and said capacitive element;
• and
• means for consecutively opening and closing said first switch element (SWi) when said second switch element (SWR) is open, for producing small current pulses in said load and subsequently transferring energy from said load to said capacitive element.