Control system for the movement of a piston

Abstract

A control system is provided for controlling the movement of the piston of the fluid-pumping device, the piston being displaceable in a block of the fluid-pumping device and being driven by a motor fed by a voltage, comprising a semiconductor electronic system cyclically applying the voltage to the motor to move the piston, a resistive element, a capacitive element, a piston-position sensor to indicate the passage of the piston by a point at the block, the capacitive element being charged by means of the resistive element, at each cycle of application of voltage to the motor, the capacitive element being discharged, at least partly, when the piston passes by the point.

1 . A control system for controlling the movement of a piston in a fluid-pumping device, the piston being displaceable in a block of the fluid-pumping device and being driven by a motor fed by a voltage, the system comprising: 
 a semiconductor electronic device having an outlet and an inlet, the semiconductor electric device cyclically applying the voltage to the motor to drive the piston;    a resistive element;    a capacitive element;    a piston-position sensor to indicate the passage of the piston by a point at the block of the fluid-pumping device; and    the system being characterized by:    the capacitive element being electrically connected to the semiconductor device between and re-feeding the outlet and the inlet, the capacitive element triggering the semiconductor electronic device to apply the voltage to the motor;    the capacitive element being charged by means of the resistive element at each cycle of application of voltage to the motor, the capacitive element being discharged, at least partly, when the piston passes by the point and delaying the trigger point of the semiconductor electronic device in a subsequent cycle proportionally to the time of passage of the piston by the point.    
   
   
       2 . A control system according to  claim 1 , characterized in that the semiconductor electronic device is self-fed by the voltage.  
   
   
       3 . A control system according to  claim 1 , characterized by additionally comprising a triggering semiconductor electronic device electrically connected with the inlet and with the capacitive element and resistive element.  
   
   
       4 . A control system according to of  claim 1 , characterized in that the electronic device comprises a bidirectional power switch.  
   
   
       5 . A control system according to claim, characterized in that the sensor is electrically connected with the entry of the device.  
   
   
       6 . A control system according to  claim 5 , characterized in that the device is actuated by a semiconductor electronic device.  
   
   
       7 . A control system according to  claim 6 , characterized in that the position sensor includes a contact element for contact with the piston.  
   
   
       8 . A control system according to  claim 7 , characterized in that the position sensor includes an inductive element.  
   
   
       9 . A control system according to  claim 8 , characterized in that the inductive element is electrically connected with a semiconductor device.  
   
   
       10 . A method of controlling the movement of a piston in a fluid-pumping device, the piston being displaceable in a block of the fluid-pumping device and being driven by a motor fed by a voltage, the method comprising the steps of: 
 charging a capacitive element by means of a resistive element,    monitoring the movement of the piston by means of a position sensor, and    the method being characterized by:    maintaining the charge level of the capacitive element until the position sensor has detected the passage of the piston by a predetermined point at the block, and discharging, at least partly, the capacitive element.    
   
   
       11 . A method according to  claim 10 , characterized in that, after the step of discharging, the capacitive element is again charged.  
   
   
       12 . A method according to  claim 10 , characterized in that, in the step of monitoring the movement of the piston, a contact element is actuated.  
   
   
       13 . A method according to  claim 10 , characterized in that, in the monitoring step, an inductive element is actuated.  
   
   
       14 . A fluid-pumping device comprising a piston displaceable in a block, the piston being driven by a motor fed by a voltage (V), and comprising a circuit having a semiconductor electronic device, a resistive element, a capacitive element and a piston-position sensor to indicate the passage of the piston by a point at the block; 
 the device being characterized by comprising:    the resistive element and the capacitive element being electrically connected with the semiconductor electronic device, re-feeding an outlet and an inlet of the latter;    the capacitive element being charged by means of the resistive element and being discharged, at least partly, when the piston passes by the point.    
   
   
       15 . A device according to  claim 14 , characterized in that the circuit is self-fed.  
   
   
       16 . A device according to  claim 14 , characterized in that the electronic device comprises a bidirectional power switch.  
   
   
       17 . A device according to  claim 14 , characterized in that the position sensor includes a contact element for contact with the piston.  
   
   
       18 . A device according to  claim 14 , characterized in that the position sensor includes an inductive element.