Method and appliance for controlling capacitive actuator checks measuring circuit during non-operative periods to provide correction factor for next control operation

摘要

For controlling the stroke of a capacitive actuator (P), e.g. a piezo actuator, the initiating charge is determined by measuring the charge voltage (Up) and current (Ip). During non-operative periods the actuator is disconnected, (switch (A) open), voltages are applied to the measuring circuits for current and voltage from an isolating amplifier (F) and compared with a reference voltage (Vref) to provide a correction factor for the next control operation.