Voltage/current source

Claim 9

A current source, having a current-source output port adapted for connection to a load, for driving a desired load current through a load connected to the current-source output port, the current source comprising: A. an electronic amplifier, having an amplifier output port, for producing at the amplifier output port an amplifier output voltage determined by amplifier input signals applied thereto; B. switch means connected between the amplifier and current-source output ports and operable by application of control signals thereto selectively to connect and disconnect the amplifier output port to and from the current-source output port; C. a current sensor for sensing the amplifier output current and producing a current-sensor signal indicative thereof; D. a voltage sensor for sensing the load voltage at the current-source output port and producing a voltage-sensor signal indicative thereof; and E. control circuitry, connected for reception of the current-sensor and voltage-sensor signals and for application of control signals to the switch means and amplifier input signals to the electronic amplifier, for: i. applying amplifier input signals to the electronic amplifier, while the switch means keeps the current-source output port disconnected from the amplifier port, to set the amplifier output voltage equal to the load voltage indicated by the voltage-sensor signal, ii. applying control signals to the switch means to cause it to connect the amplifier output port to the current-source output port while the amplifier output voltage equals the load voltage, and iii. thereafter applying amplifier input signals to the amplifier to cause the amplifier output current to equal the desired load current, the current source thereby minimizing the magnitudes of transients caused when the switch means connects the amplifier output port to the current-source output port.

Claim 10

A current source, having a current-source output port adapted for connection to a load, for driving a desired load current through a load connected to the current-source output port, the current source comprising: A. an electronic amplifier, having an amplifier output port, for producing at the amplifier output port an amplifier output voltage determined by amplifier input signals applied thereto; B. switch means connected between the amplifier and current-source output ports and operable by application of control signals thereto selectively to connect and disconnect the amplifier output port to and from the current-source output port; C. a current sensor for sensing the amplifier output current and producing a current-sensor signal indicative thereof; D. a voltage sensor for sensing the load voltage at the current-source output port and producing a voltage-sensor signal indicative thereof; and E. control circuitry, connected for reception of the current-sensor and voltage-sensor signals and for application of control signals to the switch means and amplifier input signals to the electronic amplifier, for: i. applying amplifier input signals to the electronic amplifier, while the switch means keeps the current-source output port disconnected from the amplifier port, to set the amplifier output voltage equal to the load voltage indicated by the voltage-sensor signal, ii. applying control signals to the switch means to cause it to connect the amplifier output port to the current-source output port while the amplifier output voltage equals the load voltage, and iii. thereafter applying amplifier input signals to the amplifier to cause the amplifier output current to equal the desired load current, the current source thereby minimizing the magnitudes of transients caused when the switch means connects the amplifier output port to the current-source output port.

Claim 11

A voltage source, having a voltage-source output port adapted for connection to a load, for applying a desired load voltage to a load connected to the voltage-source output port, the voltage source comprising: A. an electronic amplifier, having an amplifier output port, for producing at the amplifier output port an amplifier output voltage determined by amplifier input signals applied thereto; B. switch means connected between the amplifier and voltage-source output ports and operable by application of control signals thereto selectively to connect and disconnect the amplifier output port to and from the voltage-source output port; C. a voltage sensor for sensing the load voltage across a load connected to the voltage-source output port and producing a voltage-sensor signal indicative thereof; and D. control circuitry, connected for reception of the voltage-sensor signals and for application of control signals to the switch means and amplifier input signals to the electronic amplifier, for: i. applying amplifier input signals to the electronic amplifier, while the switch means keeps the voltage-source output port disconnected from the amplifier port, to set the amplifier output voltage substantially equal to the load voltage indicated by the voltage-sensor signal, ii. applying control signals to the switch means to cause it to connect the amplifier output port to the voltage-source output port while the amplifier output voltage is substantially equal to the load voltage, and iii. thereafter applying amplifier input signals to the amplifier to cause the sensed load voltage to equal the desired load voltage, the voltage source thereby minimizing the magnitudes of transients caused when the switch means connects the amplifier output port to the current-source output port.

Claim 12

A voltage source, having a voltage-source output port adapted for connection to a load, for applying a desired load voltage to a load connected to the voltage-source output port, the voltage source comprising: A. an electronic amplifier, having an amplifier output port, for producing at the amplifier output port an amplifier output voltage determined by amplifier input signals applied thereto; B. switch means connected between the amplifier and voltage-source output ports and operable by application of control signals thereto selectively to connect and disconnect the amplifier output port to and from the voltage-source output port; C. a voltage sensor for sensing the load voltage across a load connected to the voltage-source output port and producing a voltage-sensor signal indicative thereof; and D. control circuitry, connected for reception of the voltage-sensor signals and for application of control signals to the switch means and amplifier input signals to the electronic amplifier, for: i. applying amplifier input signals to the electronic amplifier, while the switch means keeps the voltage-source output port disconnected from the amplifier port, to set the amplifier output voltage substantially equal to the load voltage indicated by the voltage-sensor signal, ii. applying control signals to the switch means to cause it to connect the amplifier output port to the voltage-source output port while the amplifier output voltage is substantially equal to the load voltage, and iii. thereafter applying amplifier input signals to the amplifier to cause the sensed load voltage to equal the desired load voltage, the voltage source thereby minimizing the magnitudes of transients caused when the switch means connects the amplifier output port to the current-source output port.

Claim 13

A method as defined in claim 3 where the stp of applying an analog amplifier input signal to the electronic amplifier comprises: A. applying to the electronic amplifier, as the analog amplifier input signal, the voltage represented by the digital PID value only if the digital PID value is within a predetermined range; and B. applying a predetermined clamp voltage as the analog amplifier input signal if the digital PID value is outside the predetermined range.

Claim 14

A method as recited in claim 3 further comprising the steps of: A. sensing the load voltage and setting the output voltage of the amplifier substantially equal to the sensed load voltage before connecting the amplifier output port across the load; and B. performing the step of connecting the amplifier to the load when the amplifier output voltage has reached the load voltage.

Claim 15

A method as defined in claim 8 where in the step of applying an analog amplifier input signal to the electronic amplifier comprises: A. applying to the electronic amplifier, as the analog amplifier input signal, the voltage represented by the digital PID value only if the digital PID value is within a predetermined range; and B. applying a predetermined clamp voltage as the analog amplifier input signal if the digital PID value is outside the predetermined range.

Claim 16

A method as recited in claim 4 further comprising the steps of: A. sensing the load voltage and setting the output voltage of the amplifier substantially equal to the sensed load voltage before connecting the amplifier output port across the load; and B. performing the step of connecting the amplifier to the load when the amplifier output voltage has reached the load voltage.

Claim 17

A current source for driving a desired load current through a load, the current source comprising: A. an electronic amplifier, having an amplifier output port adapted for connection to a load, for producing at the amplifier output port an amplifier output voltage determined by amplifier input signals applied thereto and thereby causing an amplifier output current to flow in a load if the load is connected across the amplifier output port; B. a sensor for sensing the amplier output current and producing an analog sensor signal indicative thereof; C. an analog-to-digital converter, connected to receive the analog sensor signal and produce a digital sensor signal therefrom; D. digital control means, connected to receive the digital sensor signal and adapted to receive a digital reference signal indicative of the desired load current, for digitally processing the digital sensor signal to determine a digital difference value representing the difference between the value represented by the digital sensor signal and that represented by the digital reference signal and to compute a proportional-integral-derivative (PID) value from the difference value, and for generating digital control signals representative of the PID value; and E. a digital-to-analog converter, connected to receive the digital control signals, for generating analog control signals therefrom the digital-to-analog converter being further connected to apply the analog control signals as amplifier input signals to the electronic amplifier so as to cause the amplifier output current to tend to equal the desired load current indicated by the digital reference signal.

Claim 18

A current source for driving a desired load current through a load, the current source comprising: A. an electronic amplifier, having an amplifier output port adapted for connection to a load, for producing at the amplifier output port an amplifier output voltage determined by amplifier input signals applied thereto and thereby causing an amplifier output current to flow in a load if the load is connected across the amplifier output port; B. a sensor for sensing the amplier output current and producing an analog sensor signal indicative thereof; C. an analog-to-digital converter, connected to receive the analog sensor signal and produce a digital sensor signal therefrom; D. digital control means, connected to receive the digital sensor signal and adapted to receive a digital reference signal indicative of the desired load current, for digitally processing the digital sensor signal to determine a digital difference value representing the difference between the value represented by the digital sensor signal and that represented by the digital reference signal and to compute a proportional-integral-derivative (PID) value from the difference value, and for generating digital control signals representative of the PID value; and E. a digital-to-analog converter, connected to receive the digital control signals, for generating analog control signals therefrom the digital-to-analog converter being further connected to apply the analog control signals as amplifier input signals to the electronic amplifier so as to cause the amplifier output current to tend to equal the desired load current indicated by the digital reference signal.

Claim 19

A current source as defined in claim 11 wherein the digital con-rol means comprises meand for (i) determining whether the PID value is within a predetermined range, (ii) setting the digital control signals to represent the digital PID value only if the PID value is within the predetermined range, and (iii) setting the digital control signals to represent a predetermined clamp value if the PID value is outside the predetermined range.

Claim 20

A current source as defined in claim 11 wherein: A. the current source further includes: i. switch means connected to the amplifier output port, adapted for connection to the load, and operable by application of switch-control signals thereto selectively to connect and disconnect the amplifier output port to and from the laod; ii. a voltage sensor for sensing the load voltage and producing analog voltage-sensor signals indicative thereof; and iii. a second analog-to-digital converter, connected to received the analog voltage-sensor signals and produce digital voltage-sensor signals therefrom; and B. the digital control means is connected for reception of the digital voltage-sensor signals and for application of switch-control signals to the switch means and includes means for: i. applying digital control signals to the digital-to-analog converter, while the switch means keeps the current-source output port disconnected from the amplifier port, to cause the digital-to-analog converter to set the amplifier output voltage subvstantially equal to the load voltage indicated by the voltage-sensor signal, ii. applying switch-control signals to the switch means to cause it to connect the amplifier output port to the load while the amplifier output voltage is substantially equal to the load voltage, and iii. thereafter applying to the digital-to-analog converter the digital control signals representing the PID value.

Claim 21

A current source as defined in claim 13 wherein the digital control means comprises means for (i) determining whether the PID value is within a predetermined range, (ii) setting the digital control signals to represent the digital PID value only if the PID value is within the predetermined range, and (iii) setting the digital control signals to represent a predetermined clamp value if the PID value is outside the predetermined range.

Claim 22

A current source as defined in claim 11 wherein: A. the current source further includes: i. a voltage sensor for sensing the load voltage and producing analog voltage-sensor signals indicative thereof; and ii. a second analog-to-digital converter, connected to receive the voltage-sensor signals and produce digital voltage sensor signals therefrom; and B. the digital control means includes (i) a read-write memory for storing instructions for computing the PID value from the reference value and the digital sensor signal and (ii) means for executing the stored instruction, the read-write memory being operable to replace the instructions for computing the PID feedback signals from the reference value and the digital sensor signals with instructions for computing the PID signals from the reference value and the digital voltage-sensor signals so as to convert the current source to a voltage source.

Claim 23

A current source as recited in claim 15 wherein: A. the current source further includes switch means connected to the amplifier output port, adapted for connection to the load, and operable by application of switch-control signals thereto selectively to connect and disconnect the amplifier output port to and from the load; and B. the digital control means is connected for reception of the digital voltage-sensor signals and for application of switch-control signals to the switch means and includes means for: i. applying digital control signals to the digital-to-analog converter, while the switch means keeps the current-source output port disconnected from the amplifier port, to cause the digital-to-analog converter to set the amplifier output voltage substantially equal to the load voltage indicated by the voltage-sensor signal, ii. applying switch-control signals to the switch means to cause it to connect the amplifier output port to the load while the amplifier output voltage is substantially equal to the load voltage, and iii. thereafter applying to the digital-to-analog converter the digital control signals representing the PID value.

Claim 24

A voltage source for applying a desired load voltage to a load, the voltage source comprising: A. an electronic amplifier, having an amplifier output port adapted for connection to a load, for producing at the amplifier output port an amplifier output voltage determined by amplifier input signals applied thereto; B. a sensor for sensing the load voltage and producing an analog sensor signal indicative thereof; C. an analog-to-digital converter, connected to receive the analog sensor signal and produce a digital sensor signal therefrom; D. digital control means, adapted to receive a digital reference signal indicative of the desired load voltage and connected to receive the digital sensor signal, for digitally processing the digital sensor signal to determine a digital difference value representing the difference between the value represented by the digital sensor signal and that represented by the digital reference signal and to compute a proportional-integral-derivative (PID) value from the difference value, and for generating digital control signals representative of the PID value; and E. a digital-to-analog converter, connected to receive the digital control signals, for generating analog control signals therefrom, the digital-to-analog converter being further connected to apply the analog control signals as amplifier input signals to the electronic amplifier so as to cause the load voltage to tend to equal the desired load voltage indicated by the digital reference signal.

Claim 25

A voltage source for applying a desired load voltage to a load, the voltage source comprising: A. an electronic amplifier, having an amplifier output port adapted for connection to a load, for producing at the amplifier output port an amplifier output voltage determined by amplifier input signals applied thereto; B. a sensor for sensing the load voltage and producing an analog sensor signal indicative thereof; C. an analog-to-digital converter, connected to receive the analog sensor signal and produce a digital sensor signal therefrom; D. digital control means, adapted to receive a digital reference signal indicative of the desired load voltage and connected to receive the digital sensor signal, for digitally processing the digital sensor signal to determine a digital difference value representing the difference between the value represented by the digital sensor signal and that represented by the digital reference signal and to compute a proportional-integral-derivative (PID) value from the difference value, and for generating digital control signals representative of the PID value; and E. a digital-to-analog converter, connected to receive the digital control signals, for generating analog control signals therefrom, the digital-to-analog converter being further connected to apply the analog control signals as amplifier input signals to the electronic amplifier so as to cause the load voltage to tend to equal the desired load voltage indicated by the digital reference signal.

Claim 26

A voltage source as recited in claim 17 wherein: A. the voltage source further includes switch means connected to the amplifier output port, adapted for connection to the load, and operable by application of switch-control signals thereto selectively to connect and disconnect the amplifier output port to and from the load; and B. the digital control means is connected for application of switch-control signals to the switch means and includes means for: i. applying digital control signals the digital-to-analog converter, while the switch means keeps the current-source output port disconnected from the amplifier port, to cause the digital-to-analog converter to set the amplifier output voltage substantially equal to the load voltage indicated by the voltage-sensor signal, ii. applying switch-control signals to switch means to cause it to connect the amplifier output port to the load while amplifier output voltage is substantially equal to the load voltage, and iii. thereafter applying to the digital-to-analog converter the digital control signals representing the PID value.