DIALYSIS MACHINE HAVING MULTI-INPUT VOLTAGE CAPABLE HEATER
First Claim
1. A medical fluid heating system operable with different supply voltages comprising:
- first and second heater elements;
first and second power lines;
first, second and third switches in electrical communication with the first and second power lines, the switches configured such that (i) in a first switch state the first and second heater elements are placed in series, solely via a closing of the first switch, for operation with a first supply voltage applied to the first and second power lines, and (ii) in a second switch state the first and second heater elements are placed in parallel, via the second and third switches, for operation with a second supply voltage applied to the first and second power lines, anda control element configured to automatically set the switches in the first or the second switch state based upon a signal sent to the control element indicative of the first or the second supply voltage.
1 Assignment
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Accused Products
Abstract
A medical fluid heating system operable with different supply voltages including first and second heater elements: first and second power lines, first, second and third switches in electrical communication with the first and second power lines, the switches configured such that (i) in a first switch state the first and second heater elements are placed in series, solely via a closing of the first switch, for operation with a first supply voltage applied to the first and second power lines, and (ii) in a second switch state the first and second heater elements are placed in parallel, via the second and third switches, for operation with a second supply voltage applied to the first and second power lines, and a control element configured to automatically set the switches in the first or the second switch state based upon a signal sent to the control element indicative of the first or the second supply voltage.
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Citations
22 Claims
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1. A medical fluid heating system operable with different supply voltages comprising:
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first and second heater elements; first and second power lines; first, second and third switches in electrical communication with the first and second power lines, the switches configured such that (i) in a first switch state the first and second heater elements are placed in series, solely via a closing of the first switch, for operation with a first supply voltage applied to the first and second power lines, and (ii) in a second switch state the first and second heater elements are placed in parallel, via the second and third switches, for operation with a second supply voltage applied to the first and second power lines, and a control element configured to automatically set the switches in the first or the second switch state based upon a signal sent to the control element indicative of the first or the second supply voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A medical fluid heating system operable with different supply voltages comprising:
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first and second heater elements; first and second power lines; first, second and third switches in electrical communication with the first and second power lines, the switches configured such that (i) in a first switch state for the first, second and third switches, the first and second heater elements are placed in series for operation with a first supply voltage applied to the first and second power lines, (ii) in a second switch state for the first, second and third switches, the first and second heater elements are placed in parallel for operation with a second supply voltage applied to the first and second power lines, and (iii) wherein at least one of the first, second and third switches is configured to open before making a switch closure contact to deter short circuiting; and a control element configured to automatically set the switches in the first or the second switch state based upon a signal sent to the control element indicative of the first or the second supply voltage. - View Dependent Claims (16, 17, 18)
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19. A medical fluid heating system operable with different supply voltages comprising:
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first and second heater elements; first and second power lines; first, second and third switches in electrical communication with the first and second power lines, the switches configured such that (i) in a first switch state for the first, second and third switches, the first and second heater elements are placed in series for operation with a first supply voltage applied to the first and second power lines, and (ii) in a second switch state for the first, second and third switches, the first and second heater elements are placed in parallel for operation with a second supply voltage applied to the first and second power lines; and a control element configured to (i) automatically set the switches in the first or the second switch state based upon a signal sent to the control element indicative of the first or the second supply voltage, and (ii) ensure that at least one of the switches is deactivated before setting the switches in one of the first or the second switch state to deter short circuiting. - View Dependent Claims (20, 21)
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22. A medical fluid heating system operable with either 120 or 240 VAC line voltages comprising:
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a heater circuit with an array of resistive heating elements for warming a medical fluid solution before delivering it to the patient; a controller for generating a command signal to the heater circuit to maintain the fluid solution at a desired temperature and for delivering a quantity of heated medical fluid solution to the patient; and a voltage detection circuit for detecting whether line voltage is approximately 120 or 240 VAC and for producing a voltage logic output indicative of line voltage; the heater circuit further including; an array of TRIACs electrically connected to the array of heating elements for passing current through the array of heating elements; and a switch circuit connected to the array of TRIACs, responsive to the voltage logic output and command signal, to switch the states of individual TRIACs in the array to determine different current paths through the array of heating elements depending on line voltage so that the heater warms the medical fluid solution at approximately the same rate regardless of whether the line voltage is 120 or 240 VAC.
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Specification