Circuit arrangement for charging and discharging capacitive final control element, especially piezo element in fuel injector, has charging circuit for charging final control element, discharge circuit with winding and discharge switch

摘要

The circuit arrangement has a first capacitor (C1) charged to a defined operating voltage (Ub) relative to a reference potential (GND) by a first power source, a DC/DC converter supplied with this operating voltage for charging a second capacitor (C2) to a higher intermediate circuit voltage, a charging circuit parallel to the second capacitor for charging the final control element (P1) in series with a choke (L1) and load switch (T2';T4) and a discharge circuit in parallel with the final control element with a aeries circuit of a winding and discharge switch (T3).