JPS62502773A - Voltage source/current source device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Voltage source/current source device Background of the invention The present invention relates to a voltage source device and a current source device, and more particularly, to a voltage source device and a current source device. The present invention relates to a voltage source/current source device used in test equipment.

m when testing analog circuits and sometimes 1 when testing digital circuits. Passing a predetermined current with extremely limited characteristics or such a predetermined It is often necessary to apply a voltage. For example, power supply noise To test noise resistance, input a signal that combines a DC value and an AC component. It is considered desirable that To test the load-bearing capacity of a power supply, the equipment under test must be Connect a current source or sink to the output terminal of the power supply at the It is only necessary to provide the specified load to the power supply device.

When such current source device or voltage source device is incorporated into automatic test equipment, You may encounter some types of problems. As an example, the current inside such automatic test equipment The source device is one that is frequently connected and disconnected from the device under test, and The current source device has a very high input voltage of 0 before connection (i.e. in the open circuit). −Dance is characterized by current υ, and therefore generates high transient voltages when connected. There is a tendency to This may destroy the test equipment, or even damage the test equipment. That's not a very good thing.

In addition, certain types of equipment under test have voltage limits, and current source devices may exceed their voltage limits. Do not generate voltages that exceed to prevent the voltage from exceeding such withstand voltage limits. To prevent this, a limiting device should be installed inside the feedback system of the current source device. Although this is often done, such configurations inherently have a slow response time. . That is, they can only react to overvoltages at their output terminals; Overvoltage cannot be predicted. Therefore, overvoltage can be suppressed by using a current source device. The output terminals cannot be completely effective unless sophisticated auxiliary circuitry is provided.

As a final note, the current source devices used inside automatic test equipment typically come in a variety of types. Used for various loads. Such current source device is a fee 1' bank type device. A type of feed that provides stable operation for one type of load. Buck systems can be very unstable with other types of loads.

For the above reasons, in order to effectively deal with various loads, conventional Different types of feedback systems used in It was necessary to provide a switching circuit for this purpose.

An object of the present invention is to easily perform the function of suppressing the return voltage without using an auxiliary circuit. and the transient response at the time of connection switching is significantly reduced. Furthermore, it requires many selectively used circuits and switching operations associated with those circuits. Allows feedback adjustments to be made to adjust currents and voltages without requiring It is about supplying.

Summary of the invention The above purposes, as well as some of their related purposes, are detects the voltage across the load before the electrical amplifier is connected across the load. Most of all, it will be achieved.

A load where the amplifier output voltage is detected while the amplifier is not yet connected to the load. The voltage is set to . When the amplifier output voltage is equal to the load voltage, The output voltage of the amplifier is then adjusted until the desired load current is obtained. can be made to change. Before the amplifier is connected to the load, the output voltage of the amplifier is Since it is controlled not according to the output power supply but according to the voltage of the load, the Large over-responses can be avoided.

Another aspect of the invention is that the control of the electrical amplifier is performed using a digital signal from the output current detector. This is what is done by the input digital circuit. This digital circuit is Calculate the difference between the input digital signal and the reference digital signal representing the desired current value. put out

Next, the digital circuit processes the difference value obtained by this calculation to calculate proportional, integral, and differential values. minute (PID) feedback signal. .

The specific Nora Nota value used to generate this PID value is It is decided according to the load, and the stability of the equipment is determined when those loads are driven. Selected to be guaranteed. The digital circuit outputs a control output signal representing the PID value. Occur.

This control output signal is converted to an analog type and then d] is used as an input signal to the device.

The digital circuit includes a read/write memory, and a discharge current source device is used. Programming to change parameters from P according to the load of the other party is easy. Since proportional, integral, and differential processing is performed digitally, the above parameters data by changing the contents of the read/write memory that stores them. You can easily modify the example. Therefore, it can be used without using a lot of auxiliary hardware. It will always have a wide range of applications.

Yet another aspect of the invention provides overcompensation without extensive auxiliary hardware. Uncompensated overvoltage suppression is easily achieved. More specifically, control signals Whether the PID value is outside the predetermined range in the algorithm used to generate the All you have to do is include a test to determine whether it is true or not. If the PID value is within this predetermined range external to the amplifier, the signal used as the input signal to the amplifier is not a PID value. determined by predetermined limit values.

As described above, the output can be achieved without using auxiliary hardware and without overcompensation. Overvoltage suppression of the power voltage is performed.

Brief description of the drawing These and other features and advantages of the present invention will be further described with reference to the accompanying drawings. I will explain in conjunction. Of the accompanying drawings, FIG. 1 depicts a voltage source/power supply embodying the teachings of the present invention. A simplified block diagram of the flow source device, and Figure 2 shows the device software. Figure 1 is a simplified diagram illustrating the overvoltage suppression function performed. A part of the test equipment for testing the child circuit is illustrated, and this illustrated part is A device that applies a predetermined voltage or flows a predetermined current to the terminals of the testing device, That is, it drives the device under test. The device under test may be mounted, for example, on a fixed support (not shown). Once placed, the test node (test connection point) of the device under test will be set to the desired voltage. It is connected to drive terminals 10 and 12 to apply a current or to flow a desired current.

When the device under test is placed on the fixed support, the detection terminals 14 and 16 are connected to the device under test. These nodes are often connected to the drive terminal lO. This is the same notebook 9 to which 12 is connected.

When you want to drive the notebook to which drive terminals 10 and 12 are connected, use the test equipment. A host computer 18, which controls the entire system, interfaces via a bus 20. This sends a signal to the interface circuit 22, which causes the loop control to be sent to the interface circuit 22. transmits information to controller 24 that two sets of relay switches 26 and 28 should be closed. let The loop controller 24 includes, for example, a microprocessor and the microprocessor. It consists of a peripheral circuit of the processor, and this peripheral circuit is connected to the host computer. It includes a read/write memory 25 for storing information received from the computer 18. Ru. This information includes the instructions that make up the program and the loop controller 2. 4 must be used to perform its functions. ing. Once the information that relay switches 26 and 28 are to be closed is stored, the router The controller 24 operates a relay drive circuit (not shown) to turn those switches. Close. When switches 26 and 28 are closed, drive terminals 10 and 12, respectively, are tested. is connected to the test equipment ground and to another switch 30.

To drive the node to which the drive terminals 10 and 12 are connected, the loop controller 2 4 sends a digital signal to the D/A converter (digital-analog converter park) 32. send out the issue. The D/A converter 32 converts this digital signal into a corresponding analog After converting it into an analog signal, it is input to the input terminal of the drive amplifier 34. Dynamic amplifier 34 applies a desired value of output voltage to the device under test. drive width The device 34 sends the amplified output signal to the relay switch 3 via a programmable resistor 36. Send to o. As described later, the relay switch 3o has switches 26 and 28 closed. is closed by the loop controller 24. Switch 30 is closed When the drive amplifier 34 is connected to the device under test, the drive amplifier 34 is connected to the device under test. It becomes possible to drive the position. Gain of drive amplifier 34, programmable resistance The resistance value of 36 and the timing of conversion by the KD/A converter 32 are determined by the loop. is controlled by a control signal sent on line 37 from controller 24.

When the circuit of FIG. 1 operates as a current source device, the loop controller 2 4 sets the value of its own digital output signal according to the output current value of the drive amplifier 34. ing. More specifically, the potential difference C (voltage) between both ends of the programmable resistor 36 is A current sense amplifier 38 receives as input. This potential difference is the output voltage of the drive amplifier 34. It is proportional to the flow. The signal sent on loop controller 24 line 48 The detection signal holding circuit (track and hold circuit) 50 The output of the current detection amplifier 38 is held. A/D converter (analog-digital converter) 52 is also sent on line 48 from the loop controller 24. Depending on the signal being emitted, convert this retained analog signal into digital form Then, the converted digital signal is sent to the loop controller 24. Thus le The loop controller 24 obtains information on the current value of the output current of the drive amplifier. loop The controller 24 receives this difference value and the value sent from the host computer 18 in advance. Calculate the difference from the standard value.

Depending on the value of the parameter received from the host computer 18, the loop controller The controller 24 digitally processes the feedback signal from the A/D converter 52. , here a value called a PID value (proportional/integral/derivative value) is calculated. PID value and Generally speaking, is the sum of three values, each of which has an individual relationship. A number is added, ie, multiplied by a factor. The three values are the difference value itself, this value, These are the integral value of the difference value and the differential value of this difference value. The stored coefficient values are The host computer This is the value included in the parameter sent from 18.

In many cases, at least one coefficient value is "0". Loop controller 24 The signal sent to the D/A converter 38 is normally a signal representing this PID value. be.

However, the PID value is sometimes determined by the node of the device under test to which the drive terminal is connected. The voltage value at the output voltage must be within that range. It may occur as follows. The present invention employs a digital control method. Therefore, compared to using an analog method, it is not possible to completely prevent such overvoltage. It is easy to Some analog current source devices limit the voltage within a specified range. Sometimes we see some kind of circuitry in its feedback path to , however, by placing such a circuit in the feedback path, the sudden This type of limiting circuit is ineffective in preventing overvoltages that occur in the circuit. Ana In a log type current source device, the output of the drive amplifier rather than in the foot 5 back path It is not impossible to provide some kind of overvoltage suppression circuit at the terminals, but such Overvoltage suppression circuits often operate at such high voltage levels that their configuration cannot be implemented in practice. This complicates the flow source device and increases its manufacturing cost. However, the digital control method of the present invention In the formula, overvoltage suppression is calculated by calculating the value of the signal input to the D/A converter 32. easily performed as part of the process.

Fig. 2 shows a method for suppressing overvoltage, and the figure shows /I/ - Fuco 7 Among the program loops executed by the controller 24, the The connected parts are illustrated in a simplified manner.

Block 54 at the top of this flowchart indicates that the loop controllers are A, /D. Receiving the signal value of the detector signal from converter 52 is shown. loopcon Controller 24 then receives information from host computer 18, as indicated by block 56. Fetch the latest supplied reference value and calculate the difference between this reference value and the detector signal value. put out In order to calculate the value from P, the loop controller 24 calculates the PID value. It is necessary to etch each coefficient value seven times. The coefficient of the differential element of the PID value is “0” If not, the loop controller 24 also sends the previous difference value (difference value). need to be checked. Also, if the coefficient of the integral element of the value from P is not "o", The loop controller 24 further stores a value representing the sum of the difference values calculated so far. We also need to fetch the data. Block 58 represents those steps. Ru.

Loop controller 24 then calculates the PID value. When the coefficient of the integral element is “0” If not, the process of updating the accumulated difference value signal that must be stored is Included in this. Block 60 represents those steps.

To set a limit on the voltage value to suppress overvoltage, the PID value must be within a predetermined value range. The loop controller only needs to execute a test to determine whether or not. Illustrated implementation In the example, this test is performed when the PID value is at a predetermined overvoltage, as shown in block 62. This is done by determining whether it is larger than a suppression value (clamp value). P.I. If the D value is not greater than the clamp value, the signal that changes the PID value is sent to the D/A controller. The output voltage of the drive amplifier exceeds the predetermined voltage limit even when sent to the converter 32. Since there is no PID value, loop controller 24 displays the PID value as shown in block 64. sends out a signal.

On the other hand, if the PID value is greater than the clamp value, if the signal representing the PID value is is sent to the D/A converter 32, the output of the drive amplifier 34 will exceed the voltage limit. I will be able to do it. Therefore, the loop controller 24 is connected to the PI as shown in block 66. A signal representing a clamp value is sent out instead of a signal representing a D value.

While the circuit in Figure 1 is actually driving the nodes of the device under test in current source mode, The circuit controls the output voltage of the drive amplifier according to the output current of the drive amplifier. . However, no output current exists before drive amplifier 34 is connected to the device under test. Therefore, if control based on the output current has already been performed before the switch 30 is closed, If so, the output voltage of the drive amplifier will rise to the voltage generated by the power supply itself. This will result in the characteristic of being rejected. This is undesirable. what Therefore, this makes it easy for a large return response to occur at the moment the connection is completed. This is because that. In order to avoid such a situation, "soft connect" is It has the following characteristics.

To implement this soft connect feature, loop controller 24 first Switches 26 and 28 are closed, followed by switch 30. switch 2 6 and 28, the pair of detection terminals are connected to both inputs of the voltage detection amplifier 68. connected to the power terminal. The gain of the voltage detection amplifier 68 is determined by the loop controller 24. is controlled in response to a signal sent on control line 7o. That on control line 70 The other signals are first sent to the voltage detection amplifier 68 to the 2' detection value holding circuit 72. The latest output signal of A converter 74 converts this held signal into a digital signal.

The loop controller 24 receives this digital signal by receiving it. Obtain information on the voltage between the terminals of the device under test to be driven.

All of these are performed before switch 30 is closed. Meanwhile, loop The amount by which the controller 24 controls the output of the drive amplifier is This is not the current value of the amplifier but the detected voltage value of the device under test. To explain in more detail, The loop controller 24 operates the drive amplifier 34 to adjust its output voltage value to that of the device under test. Change it to be equal to the voltage value. The loop controller 24 is connected to the drive amplifier 3 When the output voltage of 4 reaches the voltage of the device under test, close the switch 30, and then Then, control of the currently driven amplifier is started according to the output current. As a result, the voltage of the device under test and the output voltage of the drive amplifier, i.e. when the switch 30 is closed. There are no voltage differences that would cause a transient response.

The foregoing portions of this specification are directed solely to the current source configuration of the circuit of FIG. The focus was on its function as a station. This circuit is suitable for use as a voltage source device. Although it is easy to read, a detailed explanation of the functions in voltage source mode is provided. is unnecessary. To change from current source mode to voltage source mode 9, simply Host computer] 8 loads the new program into the loop controller 24 At the same time, the reference value representing the desired voltage value is also set to the loop controller. It is sufficient to explain that it is only given to 24. According to this new program , P, the value depends on the detected voltage of the device under test, not on the detected amplified valley current. Calculated based on The above-mentioned soft connect feature is similar to the voltage source mode 1. Although not as important as in current source mode, it is also used in voltage source mode. It is possible.

As is clear from the above description, the present invention has a very wide range of applications in voltage source/current source devices. It provides a path. The present invention includes many circuits that are used selectively. This allows you to easily adapt the characteristics of your control equipment to a wide variety of load types. It also has an elaborate overvoltage suppression circuit (lamp circuit) at its output terminal. This effectively prevents overvoltage without the need for a Furthermore, the present invention The soft connect feature makes this feature unique, especially in current source motors. Connection transients that could otherwise occur are eliminated. The present invention is as described above. , represents a significant advance in the field.

FIG. 2 ANNEX To Tll;E IDITERNATIONAL 5EARCH RE? oRT ON

Claims (18)

[Claims] 1. In a method of flowing a desired load current to a load using an electric amplifier, A. A step for detecting the voltage of the load when the amplifier is not connected to the load. Tep and B. setting the output voltage of the amplifier substantially equal to the detected load voltage; step and C. When the output voltage of the amplifier reaches the load voltage, the amplifier is connected to the load. D. After that, the load current generated by the above is detected. step and E. The output voltage of the amplifier is controlled so that the detected load current is substantially equal to the desired load current. a method characterized by the step of: 2. In a method of applying a desired voltage to a load using an electric amplifier, A. A step for detecting the voltage of the load when the amplifier is not connected to the load. Tep and B. setting the output voltage of the amplifier to the detected load voltage; C. When the output voltage of the amplifier reaches the load voltage, the amplifier is connected to the load. D. After that, detect the load voltage caused by the above. step and E. The output voltage of the amplifier is controlled so that the detected load voltage is substantially equal to the desired load voltage. a method characterized by the step of: 3. Use an electrical amplifier with an amplifier output terminal suitable for connecting to the load. A method for causing a desired load current to flow through a load, the amplifier comprising: outputting an amplifier output voltage determined by the amplifier input signal to the amplifier output terminal; In this method, A. connecting the amplifier output terminals across the load; B. A step that detects the amplifier output current and generates a digital detector signal representing it. and C. digitally processing the digital detector signal and representing the digital detector signal; and a predetermined reference value representing the desired load current. Determine the minute value and calculate the digital proportional, integral, and differential value (PID value) from the difference value. step, D. The analog voltage value represented by the digital PID value is input to the electrical amplifier. input as an amplifier input signal, and the amplifier output current is expressed as the reference value. the desired load current being equal to the desired load current. . 4. The step of inputting the analog amplifier input signal to the electrical amplifier, A. Only if the digital PID value is within a predetermined value range, the digital PID The voltage value represented by the value is used as the input signal to the analog amplifier, and inputting the information into the device; B. predetermined overvoltage suppression when the digital PD value is outside the predetermined value range; Claims characterized in that a voltage value is input as the analog amplifier input signal. The method described in section 3. 5. A. Before connecting the amplifier output terminals to both ends of the load, the load voltage detecting the output voltage of the amplifier to be substantially equal to the detected load voltage. Further steps to configure and B. When the amplifier output voltage reaches the load voltage, the amplifier is connected to the load. a further step of performing said step connected to said claim 1. The method described in Section 3. 6. The step of inputting the analog amplifier input signal to the electrical amplifier, A. Only if the digital PID value is within a predetermined value range, the digital PID The voltage value represented by the value is used as the input signal to the analog amplifier, and inputting the information into the device; B. When the digital PID value is outside the predetermined value range, a predetermined overvoltage suppression A further feature is that the limiting voltage value is input as the analog amplifier input signal. The method according to claim 5. 7. The amplifier output voltage is determined by the amplifier input signal input to the amplifier. It has an amplifier output terminal suitable for connecting to a load to output to the amplifier output terminal. A method for applying a desired load voltage to the load using an electrical amplifier comprising: ．． connecting the amplifier output terminals across the load; B. a step of detecting the load voltage and generating a digital detector signal representative thereof; and C. digitally processing the digital detector signal and representing the digital detector signal; and a predetermined reference value representing said desired load voltage. Determine the minute value and calculate the digital proportional, integral, and differential value (PID value) from the difference value. step, D. The analog voltage value represented by the digital PID value is input to the electrical amplifier. input as an amplifier input signal, and the amplifier output current is expressed by the reference value. the desired load voltage being equal to the desired load voltage. . 8. A. Before connecting the amplifier output terminals to both ends of the load, the load voltage detecting the output voltage of the amplifier to be substantially equal to the detected load voltage. Steps to configure and B. When the amplifier output voltage reaches the load voltage, the amplifier is connected to the load. and performing said step connecting to said method. Method described. 9. It has a current source output terminal suitable for connection to a load, and is connected to the current source output terminal. In a current source device that causes a desired load current to flow through the load, A. An amplifier having an amplifier output terminal and determined by an input amplifier input signal. an electric amplifier that outputs an output voltage to the amplifier output terminal; B. connected between the amplifier output terminal and the current source output terminal, and receives a control signal. The amplifier output terminal and the current source output terminal can be selectively connected and disconnected by switch means operative to disconnect; C. a current that senses the amplifier output current and generates a current detector signal representative thereof; a detector; D. a voltage detector signal that detects and represents the load voltage at the current source output terminal; a voltage detector that generates a signal; the current detector signal and the voltage detector signal. transmitting a control signal to the switch means and transmitting a control signal to the electrical amplifier; A control circuit connected to send an input signal, i. the switch means disconnects the current source output terminal and the amplifier output terminal; While holding the amplifier input signal to the electrical amplifier, setting the amplifier output voltage equal to the load voltage represented by the voltage detector signal; Set, ii. The control signal is applied to the amplifier while the amplifier output voltage is equal to the load voltage. the amplifier output terminal and the current source output to the switch means; connect the terminal, and iii. Thereafter, the amplifier input signal is sent to the amplifier, and the amplifier output signal is transmitted to the amplifier. the load current equal to said desired load current, thereby causing said switch means to increase said load current. The magnitude of the transient response when connecting the width filter output terminal to the current source output terminal is expressed as the current a control circuit configured to suppress the source device; A current source device comprising: 10. Has a voltage source output terminal suitable for connection to a load, and connects to the voltage source output terminal. In a voltage source device that applies a desired load voltage to the load, A. An amplifier having an amplifier output terminal and determined by an input amplifier input signal. an electric amplifier that outputs an output voltage to the amplifier output terminal; B. is connected between the amplifier output terminal and the voltage source output terminal, and receives a control signal. The amplifier output terminal and the voltage source output terminal can be selectively connected and disconnected by switch means operative to disconnect; C. Detects the load voltage across the load connected to the voltage source output terminal and outputs it. a voltage detector generating a voltage detector signal representing the voltage detector; D. receiving the voltage detector signal and sending a control signal to the switch means; A control circuit connected to send an amplifier input signal to the electrical amplifier, , i. The switch means disconnects the voltage source output terminal and the amplifier output terminal. transmitting the amplifier input signal to the electrical amplifier while maintaining the electrical amplifier; substantially equalizing the amplifier output voltage with the load represented by the voltage detector signal. set equal, ii. while the amplifier output voltage is substantially equal to the load voltage; sending a control signal to said switch means to connect said amplifier output terminal to said switch means; and the voltage source output terminal, and iii. After that, insert the amplifier transmitting a force signal to the amplifier to convert the sensed load voltage to the desired load voltage. , thereby causing the switch means to connect the amplifier output terminal to the current source output. The voltage source device now suppresses the magnitude of the transient response when connecting to the power terminal. , a control circuit, A voltage source device comprising: 11. In a current source device for causing a desired load current to flow through a load, A. to said load an amplifier output terminal suitable for connection, the load being connected to the amplifier output terminal; When connected, the amplifier output voltage is determined by the input amplifier input signal. An electrical amplifier that generates a voltage at the amplifier output terminals, which causes the amplifier output current to flow to the load. A purse and B. detecting the amplifier output current and generating an analog detector signal representative thereof; a detector; C. receiving the analog detector signal and generating a digital detector signal based thereon; an analog-to-digital converter connected to produce D. connected to receive the digital detector signal and the desired load current; is configured to receive a digital reference signal representative of the digital detector signal and digitally convert the digital detector signal into The value represented by the digital detector signal and the digital reference signal are Determine a digital difference value representing the difference between the value represented by Calculate proportional, integral, and differential values (PID values) based on the E. digital control means for generating digital control signals; The digital control signal a digital analog connected to receive and generate an analog control signal based on the an analog converter, further comprising: using the analog control signal as an amplifier input signal; is connected to deliver the amplifier output current to the amplifier, thereby causing the amplifier output current to equal to the desired load current represented by the digital reference signal. A current source device comprising: a digital-to-analog converter; 12. The digital control means (i) determines whether the PID value is within a predetermined range; (ii) only if the PID value is within the predetermined value range, the digital (iii) the PID resistance value is set to represent the PID value; If it is outside the predetermined value range, the digital control signal is set to a predetermined clamp value. Claim 11, characterized in that it comprises means for setting to display the The current source device described in . 13. A. The current source device is switch means connected to the amplifier output terminal, the switch means being connectable to the load; Yes, the amplifier output terminal and the load are connected by inputting a switch control signal. switch means operative to selectively connect and disconnect the ii. a voltage detector that detects the load voltage and generates an analog voltage detector signal representative thereof; a pressure detector; iii. Digital voltage detection based on the analog voltage detector signal a second analog-to-digital converter that generates a digital signal; It further contains B. The digital control means receives the digital voltage detector signal and controls the digital voltage detector signal. connected to send a switch control signal to the switch means, and a state in which the switch means disconnects the current source output terminal and the amplifier output terminal; while holding the digital control signal to the digital-to-analog converter. the amplifier output voltage to the digital-to-analog converter; setting the load voltage substantially equal to the load voltage represented by the detector signal; ii. the switch control signal while the amplifier output voltage is substantially equal to the load voltage; a signal to the switch means, and connects the amplifier output terminal to the switch means. connected to the load, and iii. Thereafter, the digital control signal representing the PID value is transmitted to the digital - comprising means for sending to an analogue converter; 12. The current source device according to item 11. 14. The digital control means (i) determines whether the PID value is within a predetermined range; (ii) only if the PID value is within the predetermined value range, the digital (iii) the PID value is set to represent the PID value; and (iii) the PID value is If it is outside the predetermined value range, the digital control signal is set to a predetermined clamp value. Claim No. 1, characterized in that it comprises means for configuring the The current source device according to item 13. 15. A. The current source device is i. a voltage detector that detects the load voltage and generates an analog voltage detector signal representative thereof; a pressure detector; ii. receives the voltage detector signal and generates a digital voltage detector signal based thereon; a second analog-to-digital converter that generates It further contains B. The digital control means (i) controls the reference value and the digital detector signal. a read/write memory for storing an instruction for calculating the PID value from the ) means for executing said stored instructions, said read-write memory comprising: Calculation of the PID feedback signal from the reference value and the digital detector signal. the command to output the voltage from the reference value and the digital voltage detector signal; The current source device is replaced with a command to calculate the PID signal, and the current source device is changed to a voltage source device. 12. A current source according to claim 11, characterized in that it is operable to convert Device. 16. A. The current source device connects a switch means connected to the amplifier output terminal. further comprising: the switch means being connectable to the load and receiving a switch control signal; The amplifier output terminal and the load are selectively connected and disconnected by inputting a signal. The sea urchin can be operated freely, and B. The digital control means receives the digital voltage detector signal and controls the digital voltage detector signal. connected to send a switch control signal to the switch means, and i. the switch means disconnects the current source output terminal and the amplifier output terminal; while holding the digital control signal in the digital-to-analog converter state. the amplifier output voltage to the digital-to-analog converter. i is set substantially equal to the load voltage represented by a voltage detector signal; i. the switch control while the amplifier output voltage is substantially equal to the load voltage; A control signal is sent to the switch means, and the amplifier output terminal is connected to the switch means in front of the amplifier output terminal. connected to the load, and iii. Thereafter, the digital control signal representing the PID value is transmitted to the digital - Claims characterized in that they include means for sending to an analog converter. The current source device according to item 15. 17. In a voltage source device for applying a desired load voltage to a load, A. It has an amplifier output terminal suitable for being connected to the load, and has an amplifier input terminal suitable for being connected to the load. an electrical amplifier that produces an amplifier output voltage at the amplifier output terminal determined by the power signal and B. a detector that detects the load voltage and generates an analog detector signal representative of it; , C. receives the analog detector signal and generates a digital detector signal based thereon; an analog-to-digital converter connected to D. adapted to receive a digital reference signal representative of the desired load voltage; connected to receive the digital detector signal; The value represented by the digital detector signal and the digital basis are Determine a digital difference value representing the difference from the value represented by the quasi-signal, and further calculate the difference Calculate the proportional integral/derivative value (PID value) based on the value and represent the PID value digital control means for generating a digital control signal; E. receiving the digital control signal and generating an analog control signal based thereon; further comprising: a digital-to-analog converter connected to the analog control; connected to send the control signal to the electrical amplifier as an amplifier input signal; such that the load voltage is the desired load voltage represented by the digital reference signal. and a digital-to-analog converter for making the Voltage source device with characteristics. 18. A. The voltage source device includes switch means connected to the amplifier output terminal. further comprising: the switch means being connectable to the load and receiving a switch control signal; The amplifier output terminal and the load are selectively connected and disconnected by inputting a signal. The sea urchin can be operated freely, and B. The digital control means sends the switch control signal to the switch means. connected to i. The switch means connects the current source output terminal and the amplifier. The digital control signal is input to the The data is sent to the digital-to-analog converter and sent to the digital-to-analog converter. The amplifier output voltage is substantially equal to the load voltage represented by the voltage detector signal. set equal to each other; ii. the amplifier output voltage is substantially equal to the load voltage; sending said switch control signal to said switch means during said switch means; connect the amplifier output terminal to the load, and iii. Thereafter, the digital control signal representing the PID value is transmitted to the digital - Claims characterized in that they include means for sending to an analog converter. The voltage source device according to item 17.