pwm the frequency divider 9 therefore has a synchronization input sync which is connected to the signal input 2 of the control device 1 at the output end the frequency divider 9 is connected to the state machine 5 which executes the charge or discharge process when the pulse sequence pwm occurs in addition the frequency divider 9 is also connected to a counter 10 which counts the number of pulses in the pulse sequence pwm during the charge or discharge process if the number of charge pulses registered by the counter 10 during charging of the actuator exceeds a specified maximum value maxcount the counter 10 delivers an abort signal to the state machine 5 whereupon the state machine aborts the charge process to this end the state machine 5 brings the control signal charge at the control output 3 to a low level thus also preventing the actuator from becoming excessively charged typical values for the maximum value maxcount are in the 20 to 30 range which is equivalent to 60 to 90 mj of energy stored in the actuator in a discharge process the counter 10 then counts down the number of discharge pulses on the basis of the number determined previously during the charge phase and likewise delivers an abort signal to the state machine 5 when the count reaches zero in order to terminate the discharge process to this end the state machine 5 brings the control signal discharge at the signal output 4 to a low level whereupon the discharge process is immediately terminated this counting down of the discharge pulses ensures that the number of discharge pulses during the.