JPH0543789U - Power circuit - Google Patents

Abstract

(57) [Summary] [Structure] The power supply circuit uses the current limiting resistor 11 to connect the load 1
It is connected to 2 and applies an output voltage to the load 12 via the current limiting resistor 11. And this power supply circuit,
An output voltage detector 8 for detecting the output voltage, and a current limiting resistor 1
Return current detection unit 13 that detects the amount of current flowing through 1
And a load voltage that is a voltage drop from the output voltage by the current limiting resistor 11 based on the current amount and the resistance value of the current limiting resistor 11, and the output voltage is adjusted so that the load voltage matches the set voltage. This is a configuration including an arithmetic unit 16 for controlling. [Effect] Even when the voltage drop due to the current limiting resistor 11 fluctuates according to the amount of current and the load voltage fluctuates, the load voltage obtained by the output voltage detection unit 8 and the return current detection unit 13 matches the set voltage. As described above, since the output voltage is controlled by the calculation unit 16 and the like, the load voltage can be stably matched with the set voltage.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a power supply circuit that outputs a constant voltage to which a current limiting resistor is connected.

[0002]

[Prior Art]

 Since the ion implantation equipment uniformly implants a prescribed amount of impurity ions into the ion irradiation target with good controllability, it can be used as an extraction electrode for extracting impurity ions from the ion source or as an accelerating tube for accelerating an ion beam of impurity ions. It is necessary to be able to stably apply an arbitrary voltage. Therefore, a power supply circuit capable of stably outputting a set voltage that is a predetermined voltage is connected to the extraction electrode, the acceleration tube, and the like.

As shown in FIG. 2, the power supply circuit described above conventionally includes an oscillating unit 51, a rectifying unit 52 having an output voltage detecting unit 55, an amplifier unit 53, and a driver unit 54. By outputting a driver signal from the section 54 to the oscillating section 51, a pulse voltage corresponding to the driver signal is output from the oscillating section 51 to the rectifying section 52 and converted into a DC voltage by the rectifying section 52. Is output as an output voltage to a load 56 such as an extraction electrode or an acceleration tube. Then, the power supply circuit detects the detected voltage corresponding to the output voltage by the output voltage detection unit 55 of the rectification unit 52 and outputs it to the amplifier unit 53, and the amplifier unit 53 is arranged so that the detected voltage and the reference voltage match. By controlling the driver unit 54 with this, even when the resistance value of the load 56 changes, the output voltage is made to match the set voltage and output.

Further, the above power supply circuit is usually connected to the load 56 via a current limiting resistor 57 having a predetermined resistance value, and the output current is limited by the current limiting resistor 57. The burnout due to the excessive output current that occurs when the load 56 is short-circuited is prevented.

[0005]

[Problems to be solved by the device]

 However, in the above conventional power supply circuit, the output voltage detection unit 55 is provided in the rectification unit 52 in the preceding stage of the current limiting resistor 57, and the load voltage, which is the voltage applied to the load 56, is applied to the current limiting resistor 57. The output voltage is lower than the output voltage.

Therefore, the load voltage is lower than the set voltage, and the voltage drop due to the current limiting resistor 57 varies depending on the amount of current flowing through the current limiting resistor 57. Even when the output voltage is stabilized by the detection of the portion 55, it becomes unstable due to the voltage drop of the current limiting resistor 57.

Therefore, the power supply circuit has a configuration in which the output voltage detection unit 55 is connected to the subsequent stage of the current limiting resistor 57 and the voltage to the load 56 is stabilized at the set voltage by directly detecting the load voltage. It is conceivable that, in the case of this configuration, when the load 56 is short-circuited, the output voltage detector 55 tries to maintain the voltage to the load 56 and causes an excessive output voltage to be output from the power supply circuit. become.

Therefore, in the present invention, it is an object of the present invention to provide a power supply circuit capable of stably matching a load voltage with a set voltage and preventing generation of an excessive output voltage when the load 56 is short-circuited. There is.

[0009]

[Means for Solving the Problems]

 In order to solve the above problems, the power supply circuit of the present invention is connected to a load via a current limiting resistor having a predetermined resistance value and applies an output voltage to the load via the current limiting resistor. And has the following features.

That is, the power supply circuit includes an output voltage detection unit that is an output voltage detection unit that detects an output voltage, a return current detection unit that is an output current detection unit that detects an amount of current flowing through the current limiting resistor, and Based on the current amount and the resistance value of the current limiting resistor, calculate the load voltage that drops from the output voltage by the current limiting resistor, and control the output voltage so that this load voltage matches the set voltage. It is characterized by having an arithmetic unit, a correction unit, an amplifier unit, and a driver unit which are control means.

[0011]

[Action]

 According to the above configuration, the output voltage of the power supply circuit is detected using the output voltage detecting means, and the current amount of the current limiting resistor is detected using the output current detecting means. The output voltage is controlled so that the load voltage that has dropped is found and this load voltage matches the set voltage. Therefore, this power supply circuit performs arithmetic control so that the load voltage matches the set voltage even when the voltage drop due to the current limiting resistor fluctuates depending on the amount of current flowing through the current limiting resistor and changes the load voltage. Since the output voltage is controlled by the means, the load voltage can be matched with the set voltage in a stable state. Also, in this power supply circuit, the output voltage detection means detects the output voltage of the previous stage of the current limiting resistor, so even if the output current of the power supply circuit increases due to a short-circuited load, the output voltage detection means detects overvoltage. Can be prevented.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to FIG.

As shown in FIG. 1, the power supply circuit according to the present embodiment has an oscillating unit 1 including a high frequency transformer 2 and a transistor 3. A DC voltage is applied to one terminal of the primary coil of the high frequency transformer 2, and the collector terminal of the transistor 3 is connected to the other terminal of the primary coil. .. A driver unit 4 (arithmetic control unit) is connected to the base terminal of the transistor 3, and a driver signal is input from the driver unit 4. The transistor 3 is configured to perform a switching operation on the DC voltage applied to the primary coil of the high frequency transformer 2 according to the driver signal.

The high-frequency transformer 2 has a secondary coil that transforms the DC voltage applied to the primary coil, and the secondary coil becomes a primary coil by the switching operation of the transistor 3. The secondary voltage is generated in proportion to the winding ratio of. The secondary coil is connected to the rectification unit 5 and outputs a pulsed secondary voltage to the rectification unit 5.

The rectification unit 5 has a rectification circuit composed of a diode 6 and a smoothing circuit composed of a capacitor 7. The rectification circuit rectifies the secondary voltage by half-wave rectification or full-wave rectification, and then smoothes it. By smoothing the secondary side voltage rectified by the circuit, a DC voltage proportional to the pulse width of the driver signal is formed and used as the output voltage between the power supply terminals 10a and 10b. The rectifier 5 also has an output voltage detector 8 (output voltage detector) that divides the DC voltage output from the smoothing circuit, and the output voltage detector 8 divides the DC voltage to be the output voltage. The detected voltage that has been pressed is output to a correction unit 9 (operation control means) described later.

The rectifying unit 5 is connected to the current limiting resistor 11 via one power supply terminal 10a of the power supply circuit. The current limiting resistor 11 is connected to the other power supply terminal 10b of the power supply circuit via the load 12 and prevents generation of an excessive output current when the load 12 is short-circuited. A return current detector 13 (output current detector) is connected to the other power supply terminal 10b. The return current detection unit 13 is connected to the rectification unit 5 and the detection value output unit 14 described above, and outputs the return current detection voltage corresponding to the return current from the load 12, which is the output current of the power supply circuit, to the detection value output unit. It is designed to output to 14.

The detection value output unit 14 has an A / D converter, and the A / D converter digitizes the return current detection voltage and converts it into a return current detection signal. There is. The detection value output unit 14 is connected in a ring shape to the arithmetic unit 16 (arithmetic control unit) and the correction unit 9 via a signal cable 15 such as an optical fiber. The return current detection signal is input from the detection value output unit 14 and the detection signal is input from the correction unit 9.

The arithmetic unit 16 has an arithmetic means such as a CPU, which calculates the voltage drop of the current limiting resistor 11 based on the return current detection signal and detects the detection signal. The output voltage between the power supply terminals 10a and 10b is calculated based on the above, and the voltage drop applied to the load 12 is calculated by subtracting the voltage drop from the output voltage. A correction signal for correcting the DC voltage of the rectifier 5 is formed so that the voltage becomes the set voltage. It is desirable that the computing unit 16 detects a short circuit of the load 12 based on the return current detection signal, and interlocks with this detection to perform a stop operation of the power supply circuit, an alarm operation, or the like.

The calculation unit 16 outputs the correction signal to the correction unit 9 via the signal cable 15 described above. The correction unit 9 includes an A / D converter that digitizes the detection voltage input from the output voltage detection unit 8 and converts the detection voltage into a detection signal, an adder that adds the correction signal to the detection signal, a detection signal and a correction signal. It has a D / A converter that converts the added value of the above into an analog value and converts it into a correction detection voltage, and outputs the correction detection voltage to the amplifier section 17 (arithmetic control means). Further, the amplifier section 17 has an amplifier circuit having an input terminal to which the correction detection voltage is input and an input terminal to which the reference voltage corresponding to the set voltage is input. The pulse width of the driver signal of the driver unit 4 is controlled so that and match.

The operation of the power supply circuit having the above configuration will be described.

First, after a DC voltage is applied to the primary coil of the high frequency transformer 2 of the oscillator 1, a driver signal is output from the driver 4 to the transistor 3 of the oscillator 1. The transistor 3 repeats the switching operation at intervals according to the pulse width of the driver signal to periodically boost and lower the primary coil of the high frequency transformer 2. The step-up and step-down of the primary side coil cause the secondary side coil of the high frequency transformer 2 to generate a secondary side voltage proportional to the winding ratio of the primary side coil and the secondary side coil.

The above secondary side voltage is input to the rectification unit 5, half-wave rectified or full-wave rectified by the rectification circuit composed of the diode 6 of the rectification unit 5, and then the capacitor 7. The smoothing circuit converts it into a DC voltage proportional to the pulse width of the driver signal. After that, the above DC voltage is detected by the output voltage detector 8 by voltage division and is output to the corrector 9, while it is the output voltage between the power supply terminals 10a and 10b. It will be.

At this time, the return current detection unit 13 interposed between the power supply terminal 10 b and the rectification unit 5 detects the return current proportional to the amount of the return current flowing through the load 12 and the current limiting resistor 11. A voltage is formed and output to the detection value output unit 14, and the return current detection voltage input to the detection value output unit 14 is digitized by the A / D converter of the detection value output unit 14 to detect the return current. It has been converted to a signal.

The return current detection signal is input to the arithmetic unit 16 via the signal cable 15 and used to calculate the voltage drop of the current limiting resistor 11. Further, the detection signal in which the detection voltage is digitized is input from the correction unit 9 to the calculation unit 16, and this detection signal is used to calculate the output voltage between the power supply terminals 10a and 10b. Become. Then, the load voltage is obtained by subtracting the voltage drop from the above output voltage. Further, a correction for correcting the DC voltage of the rectifier unit 5 is made so that this load voltage matches the set voltage. A signal will be formed.

The above correction signal is input to the correction unit 9 via the signal cable 15, and is added to the detection signal input from the rectification unit 5. The added value of the correction signal and the detection signal is converted into an analog by the D / A converter of the correction unit 9 and converted into the corrected detection voltage. Then, the corrected detection voltage is input to the amplifier unit 17 and used for controlling the pulse width of the driver signal of the driver unit 4.

As described above, the power supply circuit according to the present embodiment detects the output voltage between the power supply terminals 10a and 10b by using the output voltage detection unit 8 and the return current flowing between the power supply terminals 10a and 10b. The detection unit 13 detects the voltage drop of the current limiting resistor 11 and subtracts this voltage drop from the output voltage to obtain the load voltage. The DC voltage is controlled based on the load voltage.

Therefore, even if the voltage drop due to the current limiting resistor 11 fluctuates according to the amount of current flowing through the current limiting resistor 11 and the load voltage fluctuates, this power supply circuit detects the output voltage detecting unit 8 and the return current. Since the load voltage is obtained by the unit 13 and the DC voltage of the rectifying unit 5 that is the output voltage is controlled by this load voltage, the load voltage can be made to match the set voltage in a stable state. There is. Further, since this power supply circuit detects the output voltage of the preceding stage of the current limiting resistor 11 by using the output voltage detection unit 8, even when the load 12 is short-circuited and the return current increases, the output voltage detection unit is detected. 8 is designed to prevent overvoltage.

[0028]

[Effect of the device]

 As described above, the power supply circuit of the present invention is connected to a load via a current limiting resistor having a predetermined resistance value and applies an output voltage to the load via the current limiting resistor. Output voltage detecting means for detecting the output voltage, output current detecting means for detecting the amount of current flowing through the current limiting resistor, and a current limiting resistor based on the current amount and the resistance value of the current limiting resistor. And a calculation control means for controlling the output voltage so as to match the load voltage with the set voltage.

With this, even when the voltage drop due to the current limiting resistor fluctuates depending on the amount of current flowing through the current limiting resistor to fluctuate the load voltage, the load voltage obtained by the output voltage detecting means and the output current detecting means is determined. Since the output voltage is controlled by the arithmetic control unit so that the load voltage matches the set voltage, the load voltage can be matched with the set voltage in a stable state. Also, in this power supply circuit, the output voltage detection means detects the output voltage of the previous stage of the current limiting resistor, so even if the output current of the power supply circuit increases due to a short-circuited load, the output voltage detection means This has the effect of preventing overvoltage.

[Brief description of drawings]

FIG. 1 is a block diagram of a power supply circuit according to the present invention.

FIG. 2 illustrates a conventional example and is a block diagram of a power supply circuit.

[Explanation of Codes] 1 oscillator 2 high-frequency transformer 3 transistor 4 driver unit (arithmetic control unit) 5 rectifying unit 6 diode 7 capacitor 8 output voltage detection unit (output voltage detection unit) 9 correction unit (arithmetic control unit) 11 limit Current resistor 12 Load 13 Return current detection unit (output current detection unit) 14 Detected value output unit (arithmetic control unit) 15 Signal cable 16 Arithmetic unit (arithmetic control unit) 17 Amplifier unit (arithmetic control unit)

Claims (1)

[Scope of utility model registration request] 1. A power supply circuit connected to a load via a current limiting resistor having a predetermined resistance value and applying an output voltage to the load via the current limiting resistor, the output detecting the output voltage. A voltage detection means, an output current detection means for detecting the amount of current flowing through the current limiting resistor, and a load whose voltage has dropped from the output voltage by the current limiting resistor based on the current amount and the resistance value of the current limiting resistor. A power supply circuit comprising: an arithmetic control unit that obtains a voltage and controls an output voltage so that the load voltage matches a set voltage.