| 摘要 |
<p>The apparatus comprises: a differential driver amplifier (A2) having a first input receiving the control signal through a voltage divider (R1, R2, R3, R7, R8) and a second input receiving a regulation signal and having its output connected to the control terminal of a driver transistor (T2) having its power terminals connected in series with a voltage supply, the injector coil (L4) and a current sensing device (R11) developing the regulation signal, said driver amplifier (A2) providing a command signal to the control terminal of the driver transistor (T2) causing it to conduct to saturation until a peak current level through the coil (L4) is obtained; and a comparator (A4) having a first input terminal receiving the regulation signal and a second input terminal having applied thereto a reference signal having a first value representative of the peak current level and having its output terminal connected to said voltage divider (R1, R2, R3, R7, R8), said comparator (A4) switching the reference signal to a second value representative of a holding current level by modifying said voltage divider (R1, R2, R3, R7, R8) in response to the regulation signal exceeding the first value of the reference signal, and said differential driver amplifier (A2) then providing a command signal to the control terminal of the driver transistor (T2) causing it to reduce the current flow through the coil (L4) to the holding current level until the end of the control signal once the peak current level is reached.</p> |
