Device for charging and discharging piezoelectric elements e.g. for motor vehicle common rail diesel fuel injectors, has two parallel circuits connected together at their output sides and to choke terminal

摘要

A device for charging and discharging piezoelectric elements, has a DC/DC converter (1) with charge- or switching-converter (2) and first- and second power switches (S1,S2). A stop switch (3) is connected to the piezoelectric element (P). In the charge/switching converter first- and second capacitors (C1,C2) is connected in parallel to each of the power switches and to the diodes (D1,D2). The parallel circuit of the first power switch (S1), first diode (D1) and first capacitor (C1) is connected to a first output terminal of the DC/DC converter device, and a parallel circuits of the second power switch (S2), second diode (D2) and second capacitor (C2) are connected to a second output terminal of the DC/DC converter device. The two parallel circuits are connected to one another at their output and to one terminal of a choke (L), the latter being connected at its other terminal to a first output terminal of the switching converter (2).