time ot the actual movement time may be less than equal to or greater than the nominal delay time dt if the actual movement time mt is greater than the nominal delay time dt a positive deviation time vt is sent to the calculation means 44 if the actual movement mt time is less than the nominal delay time dt a negative deviation time vt is sent to the calculation means 44 if the movement time mt and nominal delay time dt is equal an equivalent zero deviation time is produced the calculation means 44 receives the stop time ct and adds the deviation time vt to the stop time ct if the deviation time vt is positive the stop time ct will be extended by the amount of time indicated by the deviation time vt in the deviation time vt is negative the stop time ct will be decreased to occur at an earlier time the calculation means 44 receives the pulsed signal directly to drive the solenoid valve apparatus 11 with the pulsed signal at a predetermined flow rate the calculation means 44 adjusts the original pulse width with the deviation time in order to maintain open or maintain the valve element 12 to the second position for the predetermined time to produce the desired flow rate the movement time nominal delay time and the deviation time are produced and transmitted in the form of electrical signals and are calibrated or coded to indicate the respective times fig3 a illustrates the current waveform of the.