Power supply for electrochemical ion exchange

A controlled power supply for an ion exchange apparatus, the ion exchange apparatus comprising a motor and electrochemical ion exchange cell having electrodes, the power supply comprising:

• (a) an electrode power supply having an output terminal, the electrode power supply capable of receiving an AC voltage and generating a DC voltage for the electrodes at the output terminal, the electrode power supply comprising:
• (i) a DC voltage supply capable of producing a DC voltage having selectable voltage levels from the AC voltage;
• (ii) a current detector to detect the current level of the DC voltage at the output terminal;
• (iii) a voltage selector to select the voltage level of the DC voltage in relation to the detected current level;
• and
• (iv) a polarity selector to select the polarity of the DC voltage relative to the output terminal;
• (b) a supplemental power supply to generate a supplemental DC voltage for the electric motor;
• and
• (c) a microcontroller to generate control signals for the electrode power supply and the electric motor.

An ion exchange apparatus comprising:

• (a) an electrochemical cell having a fluid channel comprising a fluid inlet and a fluid outlet, and electrodes about the fluid channel and a water-splitting ion exchange membrane;
• (b) a valve to control the flow of a solution through the fluid inlet, fluid outlet, and the fluid channel of the electrochemical cell;
• (c) a motor to move a rotor in the valve;
• and
• (d) a controller to control the operation of the electrochemical cell, the valve and the electric motor, the controller comprising:
• (ii) a power supply having an electrode power supply and a supplemental power supply, the electrode power supply having an output terminal and being capable of receiving an AC voltage and generating a DC voltage for the electrodes at the output terminal, the electrode power supply comprising:
• (1) a DC voltage supply capable of producing a DC voltage having selectable voltage levels from the AC voltage;
• (2) a current detector to detect the current level of the DC voltage at the output terminal;
• (3) a voltage selector to select the voltage level of the DC voltage in relation to the detected current level;
• and
• (4) a polarity selector to select the polarity of the DC voltage relative to the output terminal;
• and
• (i) a control module having a microcontroller to generate control signals for the power supply and the electric motor.

A method of maintaining a selectable voltage across electrodes of an electrochemical cell, the method comprising:

• (a) rectifying an AC voltage and multiplying the rectified voltage to produce a pulsating DC voltage having a time-averaged value equal to the amplitude of the AC voltage multiplied by a multiplier M1;
• (b) applying the pulsating DC voltage across the electrodes;
• (c) measuring the current level delivered to the electrodes;
• and
• (d) setting the value of the multiplier M1 in relation to the measured current level.

A method of maintaining a selectable voltage across electrodes of an electrochemical cell, the method comprising:

• (a) rectifying an AC voltage and multiplying the rectified voltage to produce a pulsating DC voltage having a time-averaged value equal to the amplitude of the AC voltage multiplied by a multiplier M1;
• (b) applying the pulsating DC voltage across the electrodes and maintaining a selected polarity of the DC voltage across the electrodes;
• (c) sensing a property of the electrochemical cell;
• and
• (d) selecting the value of the multiplier M1 and the polarity of the pulsating DC voltage across the electrodes in relation to the sensed property of the electrochemical cell.