System and methods for operating a solenoid valve

A drive circuit for controlling a plurality of solenoid valves having respective solenoid coils and respective poppets configured to translate therein, said drive circuit comprising:

• a supply bus configured to couple the respective solenoid coils to a power supply and supply respective coil currents;
• respective return buses configured to provide a ground path for the respective coil currents;
• respective bipolar diodes coupled in parallel to the respective solenoid coils;
• respective switches coupled in series with the respective solenoid coils and configured to couple and decouple the respective solenoid coils to said respective return buses;
• and
• a charge pump circuit having a bank of capacitors, said charge pump circuit configured to charge said bank of capacitors using one or more of the respective coil currents through one or more of the respective solenoid valves,
• wherein said charge pump circuit is further configured to momentarily change a reference of said bank of capacitors coupled in series with the respective solenoid coils to boost a voltage applied across the respective solenoid coils when said respective switches are opened in order to accelerate a decrease in the respective coil currents through the respective solenoid valves.

A method of controlling a solenoid valve having a solenoid coil and a poppet configured to translate therein, said method comprising:

• supplying a voltage to the solenoid coil over a supply bus;
• coupling the solenoid coil to a ground path over a return bus to translate the poppet to an opened position;
• decoupling the solenoid coil from the ground path to translate the poppet to a closed position;
• directing a flyback current sourced from the solenoid coil through a flyback circuit coupled in parallel to only the solenoid coil, the flyback circuit comprising only a bipolar diode;
• charging a capacitor of a charge pump circuit using a coil current conducted through the solenoid coil;
• and
• momentarily changing a reference of the capacitor coupled in series with the solenoid coil to boost a voltage applied across the solenoid coil when the solenoid coil is decoupled from the ground path in order to accelerate a translation of the poppet to the closed position.

A drive circuit for controlling a first solenoid valve having a first solenoid coil and a second solenoid valve having a second solenoid coil, said drive circuit comprising:

• a low voltage bus configured to be energized by a power source;
• a high voltage bus;
• a control circuit coupled to said low voltage bus and said high voltage bus, and configured to:
• selectively couple said low voltage bus and said high voltage bus to the first and second solenoid coils using a shared power bus;
• and
• periodically energize each of the first and second solenoid coils using respective pulse-width-modulated (PWM) signals, each having a frequency and a duty cycle configured to regulate a current conducted through the corresponding solenoid coil;
• a flyback circuit coupled to the first and second solenoid coils and configured to energize said high voltage bus with energy stored in the first and second solenoid coils;
• and
• a charge pump circuit comprising a capacitor bank and a plurality of semiconductor switches, said plurality of semiconductor switches configured to couple said capacitor bank to the first solenoid coil or the second solenoid coil to charge said capacitor bank using the current conducted through the first solenoid coil or the second solenoid coil.