Method for controlling a dc-to-dc voltage converter

A DC-DC voltage converter (1) for driving with current at least one fuel injector (2) of a motor-vehicle internal combustion engine, said converter (1) comprising a control module (10) and an induction coil (20) that is connected to a field-effect transistor (30) comprising a drain (D), a source (S) and a gate (G), said gate (G) being connected to the control module (10) in order for said control module (10) to command the transistor (30) to an on state in which current passes between the drain (D) and the source (S) or to an off state in which current does not pass between the drain (D) and the source (S), the alternation of the on and off states of the transistor (30) generating a sawtooth current called the peak current (Ipeak), the amplitude of which is bounded by a maximum value, called the “top” value, and that allows the converter (1) to deliver an output voltage (Vout) across the terminals of a capacitor called the “intermediate” capacitor (Cint), the discharge of which is commanded by a computer via a drive module in order to command at least one fuel injector (2), the converter (1) being configured to make said output voltage (Vout) tend toward a target value, wherein the control module (10) is configured to:

• switch the transistor (30) from the off state to the on state,
• trigger a counter (120) for measuring time when the transistor (30) is switched to the on state,
• if at the end of a preset time called the “observation” time, the amplitude of the peak current (Ipeak) has not reached its maximum value, command the transistor (30) so that said transistor (30) switches from the on state to the off state,
• keep the transistor (30) in the off state for a preset time called the “cooling” time,
• command the transistor (30) so that said transistor (30) switches to the on state at the end of the cooling time.