JP2004102676A - Tracking-operable double-output series regulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost versatile double-output series regulator having a wide application range and a low-ripple/low-noise characteristic, by an inexpensive and simple method capable of utilizing the double-output series regulator equipped with two independent stabilized direct-current output as a tracking type series regulator as the need arises. <P>SOLUTION: Two series regulators are connected as shown in the figure. A current flowing in a signal wire between a positive voltage output terminal 6 and a negative voltage output terminal 15 is converted into a voltage value by a current/voltage conversion circuit 28, and the value is compared with a divided voltage output of an output voltage dividing circuit 26 by a voltage comparison circuit 27. A current control circuit 29 controls the current flowing in the signal wire so that both voltages agree with each other, and the current value is converted into a voltage value by a current/voltage conversion circuit 30, and utilized as a reference voltage of the second series regulator 33. Hereby, tracking operation can be realized. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a series-type stabilized power supply and a series regulator that convert an AC input voltage and output a stable DC voltage regardless of a load. More particularly, the present invention relates to a tracking power supply having a characteristic in which, out of a stabilized power supply having a plurality of output voltages, another output voltage is controlled following a certain output voltage.
[0002]
The present invention has been developed for the purpose of making a plurality of multi-output series regulators each having an independent DC power supply output operable as a tracking series regulator with a small change at low cost.
[0003]
[Prior art]
The internal circuit of an electronic device is generally driven by a DC power supply, while a low-frequency AC power supply is generally supplied as a commercial / home power supply. Therefore, most electronics, except those powered by batteries, require some stabilized AC-DC converter or stabilized power supply.
[0004]
A stabilized power supply is a power supply that outputs a constant DC voltage irrespective of a change in load current, and is realized mainly by two types of a series regulator and a switching regulator. Since the switching regulator includes an oscillation circuit therein, a series regulator is generally used when a low noise level in the output voltage is required. Since the stabilized DC output voltage of the series regulator is lower than the input DC voltage from the rectifier circuit, it is also called a dropper regulator. Since the power corresponding to this voltage drop is consumed as heat, the series regulator has lower power conversion efficiency than the switching regulator. Therefore, which of the switching regulator and the series regulator is adopted is determined depending on which of the noise characteristics and the power conversion efficiency is an important factor for each application.
[0005]
Also, of these stabilized power supplies, two positive and negative voltages having the same absolute value can be output, and when one output voltage is varied, the other output voltage having the opposite polarity follows the same absolute value. The power supply controlled to have is especially called a tracking power supply.
[0006]
Of the tracking power supplies, tracking type series regulators for synchronizing the output voltages of two series regulators have been realized by several methods. In the first method, the first method is, first, a master power supply, for example, a positive power supply. The output voltage of the voltage power supply is divided by a resistor or the like to generate a comparison voltage, which is compared with a high-precision reference voltage using an OP amplifier or the like. The result is negatively fed back to an output control transistor or the like to stabilize the output voltage of the master power supply. Also, by varying the voltage division ratio and changing the comparison voltage, the output voltage of the master power supply can be changed accordingly.
[0007]
Next, the slave power supply, that is, the negative voltage power supply is a stabilized power supply having the same circuit configuration as the positive voltage power supply according to the example of the preceding section, but the output voltage of the positive voltage power supply is used as the reference voltage here. The output voltage of the negative voltage power supply is compared with this reference voltage, and the midpoint of the positive output voltage and the negative output voltage is controlled by an operational amplifier or the like to be at the ground potential, thereby following the change in the output voltage of the positive voltage power supply. As a result, the negative voltage power supply can perform a tracking operation of outputting a negative voltage having the same absolute value.
[0008]
The AC voltage output from both ends of the secondary coil of the normal transformer is input to the two positive and negative stabilizing power supplies in the tracking type series regulator, and the center tap of the secondary coil has two positive and negative stabilizing power supplies. Often, they are connected to a common ground line.
[0009]
Next, in the second method, the voltage dividing ratio of the output voltage when the comparison voltage is generated in the first method is made variable, but this is made a fixed ratio. A voltage obtained by dividing the high-precision reference voltage by a variable resistor and a voltage obtained by inverting the polarity of the voltage are applied as reference voltages of a positive / negative two-system stabilized power supply. The output voltage of each of the positive and negative power supplies is controlled so that the output voltage divided by the fixed ratio is equal to the reference voltage.
[0010]
In addition, a method using an integrated circuit dedicated to a tracking power supply device in which the tracking operation control circuits according to the first and second methods are integrated has become widespread.
[0011]
[Problems to be solved by the invention]
As mentioned above, the tracking type series regulator includes a plurality of series regulators.However, depending on the application, these series regulators do not perform a tracking operation and have a completely independent stabilized DC output voltage. When considering generalization so that it can be used, the conventional tracking series regulator has the following problems. In other words, from the opposite point of view, the following problem is an obstacle when considering a configuration in which a plurality of independent series regulators can be used as a conventional tracking series regulator.
[0012]
First, as described above, in many tracking series regulators, since the center tap of the transformer secondary coil is connected to the common ground line of the positive and negative power supplies, the transformer must be independent to change to an independent two-output stabilized power supply. It is necessary to change to the one provided with the secondary coil.
[0013]
Next, in a conventional tracking series regulator, a combination of complementary semiconductor elements is often used in order to provide almost the same operating characteristics except that the polarity of the two series regulator circuits is inverted. In this case, the number of parts is increased compared to a case where two series regulators of the same circuit and the same parts are independently used, so that the burden on cost and product maintenance is increased.
[0014]
In addition, the reference voltage for stabilizing the master power supply, that is, the slave power supply that operates in accordance with the output voltage of the positive voltage power supply in the above example, that is, the negative voltage power supply, is the master power supply side in the conventional tracking type series regulator. And the reference voltage is inverted. In other words, the reference voltage generation circuit of the conventional tracking type series regulator is designed on the assumption that the master power supply and the slave power supply have a common ground potential. In the case of a regulator, it is necessary to make a drastic change such as providing a separate reference voltage generating circuit by separating the ground lines of the two, and there are many disadvantages in terms of cost and man-hours.
[0015]
Further, in the method using the integrated tracking regulator IC, it is impossible to physically separate the power supply into two independent power supplies, and even when used as a tracking type series regulator, the maximum output power is limited to transistors and the like. Generally smaller than when used. There is also a problem that the absolute values of the two positive and negative output voltages are limited to almost equal values and cannot be set to an arbitrary voltage.
[0016]
SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and an object of the present invention is to provide a two-output series regulator having two independent DC power supply outputs, which can be used as a tracking type series regulator as required, at a low cost and a simple manner. It is an object of the present invention to provide a general-purpose power supply having low ripple and low noise characteristics which is inexpensive and has a wide application range.
[0017]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, it is necessary to reduce the cost of the change by making the connection between the two series regulator circuits as sparse as possible when the two independent series regulators perform the tracking operation. is there.
[0018]
In addition, it is necessary to reduce the cost of parts procurement and circuit maintenance by configuring the two series regulators with the same circuit and parts except for slight differences.
[0019]
In the present invention, in order to solve the above-mentioned problem and achieve the above-mentioned object, in a conventional tracking power supply, the output voltage or the reference voltage from the master power supply side is applied to the slave power supply side by inverting the polarity to apply the tracking. While the operation is controlled, low-noise tracking operation control is enabled by flowing a current between the master power supply side and the slave power supply side.
[0020]
That is, in the present invention, a single connection line for flowing a current is provided between two independent series regulators having substantially the same components and circuits, and the current flowing therethrough is made proportional to the output voltage of the master power supply. On the slave power supply side, a voltage proportional to the current flowing through the connection line is generated, and this is used as a reference voltage for comparison with the output voltage on the slave power supply side.
[0021]
More specifically, in the present invention, the ground terminal of the first series regulator is connected to the positive voltage output terminal of the second series regulator as described in claim 1, and the first terminal is connected to the zero potential terminal. And the second series regulator outputs a positive voltage, and the second series regulator outputs a negative voltage. Further, a voltage between the positive voltage output line of the first series regulator and the ground line or the negative voltage output line of the second series regulator is output. The signal line to be connected is provided in a form in which the first current-voltage conversion circuit, the third current control means, and the second current-voltage conversion circuit are connected in series.
[0022]
Further, the output voltage of the first current-to-voltage conversion circuit according to claim 1 is equal to the comparison voltage obtained by dividing the output voltage of the first series regulator. The three current control means are controlled.
[0023]
In the preceding paragraph, the current made constant by the third current control means flows toward the ground line of the second series regulator, and this current is supplied to the potential of the second series regulator with respect to the ground line by the second current-voltage conversion circuit. Is converted to a voltage having This voltage is used as a reference voltage for stabilizing the output voltage in the second series regulator.
[0024]
Since the same current flows through the first current-voltage conversion circuit and the second current-voltage conversion circuit, the output of the first series regulator can be reduced by configuring both circuits with resistors having the same temperature coefficient. Suppressing a change due to a temperature change in a ratio between an output voltage of a first current-to-voltage conversion circuit controlled to be equal to a voltage obtained by dividing a voltage and an output voltage of a second current-to-voltage conversion circuit. Can be.
[0025]
Further, in the preceding paragraph, the resistors used to divide the output voltage of the first series regulator have the same temperature coefficient, so that a change in the division ratio due to a temperature change can be suppressed.
[0026]
Also, by increasing the constant current value of the output of the third current control means, that is, by increasing the current flowing through the first current-voltage conversion circuit and the second current-voltage conversion circuit, the resistance of the reference voltage to noise is improved. be able to.
[0027]
Therefore, according to the present invention, a voltage value obtained by dividing the output voltage of the first series regulator is used as a reference voltage used in a voltage comparison circuit to stabilize the output voltage of the second series regulator. Becomes possible. Then, the influence of temperature change and noise on the reference voltage can be made extremely small, and it can be made almost exactly proportional to the output voltage of the first series regulator.
[0028]
More specifically, in a tracking series regulator generally configured by connecting two series regulators as in the first aspect, the first series regulator, that is, the positive type in the case of the first aspect, is generally used. The ground line of the voltage power supply gives the reference potential as it is in the tracking type series regulator, whereas the output line having the positive potential in the second series regulator, that is, the negative voltage power supply in the example of the above-mentioned claim 1, is tracked. The reference potential is given by the type series regulator, and the polarity is reversed with respect to the positive voltage power supply. Since the conventional tracking series regulator uses a set of positive and negative voltages having the same absolute value as the reference voltages in the positive voltage power supply and the negative voltage power supply, respectively, the positive voltage power supply and the negative voltage power supply are the same circuit. It is impossible to configure, and it is necessary to configure a negative voltage power supply whose polarity is inverted from that of the positive voltage power supply by using a semiconductor element having the opposite polarity to the semiconductor element used in the circuit of the positive voltage power supply. is there.
[0029]
A feature of the present invention is that, even when two series regulators are connected to form a tracking power supply as in claim 1, the ground line is used as a reference potential on the negative voltage power supply side as well as on the positive voltage power supply. This makes it possible to configure the positive voltage power supply and the negative voltage power supply from the same circuit and components.
[0030]
The above feature of the present invention is realized by temporarily converting a reference voltage generated on the positive voltage power supply side into a current and applying the current to the negative voltage power supply side through one signal line. This makes it possible to manufacture the positive voltage power supply and the negative voltage power supply using common circuits and components, thereby reducing the parts procurement cost and circuit maintenance cost, and at the same time, the use of the positive voltage power supply and the negative voltage power supply during tracking operation. It has become possible to make the coupling extremely sparse with only one signal line.
[0031]
Therefore, according to the present invention, it is possible to change from a two-output series regulator to a tracking type series regulator with a slight circuit modification, thereby realizing a two-output series regulator or a tracking type series regulator using the same printed circuit board and components. can do.
[0032]
Also, in conventional tracking series regulators, an active element such as an operational amplifier is generally used to invert the polarity when the reference voltage or output voltage of one series regulator is applied to the reference voltage of the other series regulator. The characteristics of the active element itself are reflected in the influence of temperature change on voltage and noise resistance. If an excellent active element is used to provide good characteristics, the cost will increase.
[0033]
On the other hand, in the present invention, the output of the first series regulator is provided by using a resistor having the same temperature coefficient for the first current-voltage conversion circuit according to claim 1 and the second current-voltage conversion circuit. Fluctuation of the ratio between the voltage and the reference voltage of the second series regulator due to temperature change can be suppressed at low cost. By using a resistor having the same temperature coefficient for the output voltage dividing circuit of the first series regulator, it is possible to suppress a change in the voltage dividing ratio due to a temperature change at low cost.
[0034]
Further, in the present invention, unlike the conventional tracking type series regulator, since the positive voltage power supply and the negative voltage power supply are constituted by substantially the same circuit, components and printed circuit board pattern, the corresponding voltage in the positive voltage power supply circuit and the voltage in the negative voltage power supply circuit are reduced. By configuring each component with a component having the same temperature characteristic, a difference in temperature characteristic between the positive voltage power supply and the negative voltage power supply can be reduced at low cost. As a result, it is possible to suppress a change due to a temperature change in the difference between the absolute values of the positive and negative output voltages of the tracking regulator. In contrast, in conventional tracking series regulators, the output voltage of the positive voltage power supply and the output voltage of the negative voltage power supply have different temperature characteristics because the positive voltage power supply and the negative voltage power supply are composed of different parts. It has to be something.
[0035]
When comparing a reference voltage proportional to the output voltage of the first series regulator with a comparison voltage generated by dividing the output voltage of the second series regulator, the division ratio is changed by a variable resistor or the like. Thus, the voltage ratio of the output voltage of the second series regulator to the output voltage of the first series regulator during the tracking operation can be easily adjusted.
[0036]
The low-cost method for performing tracking operation of a two-output series regulator has been mainly described in connection with the present invention. By applying the method of the present invention, a power supply that performs the following various tracking operations can be realized at low cost. It is possible.
[0037]
First, to realize a tracking regulator capable of changing one of two DC output voltages following the other while maintaining an arbitrary voltage ratio by the two-output series regulator used in the present invention. The ground line of the first series regulator and the ground line of the second series regulator are connected to form a common ground line, and either one of them, for example, a voltage obtained by dividing the output voltage of the first series regulator is applied to the second series regulator. What is necessary is just to use it as a reference voltage in a regulator. On the other hand, it is almost impossible to change a conventional tracking regulator having two positive and negative outputs to a special tracking power supply having two positive or negative outputs as described above because a large-scale correction is required. is there.
[0038]
Second, for example, a three-output series regulator performs a tracking operation such that one of the regulators outputs a positive voltage and the other two output two negative voltages following the positive voltage output. However, it becomes possible by preparing the first, second and third series regulators used in the present invention and making slight changes. For this purpose, for example, a signal line for flowing a constant current as described in claim 1 is connected to a positive voltage output line of the first series regulator and a ground line of the second series regulator, The positive voltage output line of the regulator and the ground line of the third series regulator are connected, but two are installed, and the reference voltages of the second and third series regulators are set in the same manner as in the first embodiment. What is necessary is just to make it proportional to the output voltage. In order to perform the tracking operation of, for example, 1 positive voltage and 2 negative voltage output as described above using the conventional tracking series regulator method, it is necessary to manufacture a circuit dedicated to the application, and the application is special. The lower the demand, the higher the production cost. On the other hand, when the method of the present invention is used, a printed circuit board of a multi-output series regulator and a multi-output tracking series regulator, and in the above-described example, a three-output series regulator and a 1-positive voltage 2 negative-voltage output tracking series regulator Since the used parts can be shared, the cost competitiveness can be enhanced as compared with the conventional method, and the labor for parts procurement and circuit maintenance can be reduced.
[0039]
BRIEF DESCRIPTION OF THE DRAWINGS In the following description, similar parts or components used in the figures are indicated with the same numerals, and the already described components and components will not be repeated. Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0040]
【Example】
(First Embodiment) FIG. 2 is a block diagram showing an embodiment of a two-output series regulator according to the present invention. 2 is a block diagram of a configuration corresponding to the two-output series regulator according to claim 1, wherein the two-output series regulator includes an overcurrent limiting circuit and an overheat protection circuit for each of the two series regulators.
[0041]
First, FIG. 2 will be schematically described. Reference numeral 1 shown at the left end of FIG. 2 denotes a commercial AC power supply, and a transformer 2 is connected to the power supply. 2a and 2b are connected in parallel by a primary coil composed of windings having the same length and the same number of windings. In this way, twice the maximum allowable current as in the case of using one coil 2a can be applied to the primary side. FIG. 2 clearly shows that AC voltages are applied to the inputs of the two series regulators from the independent secondary coils 2c and 2d of the two transformers, respectively, and the two series regulators have independent outputs having no potential relation. It has become. In FIG. 2, the upper one is the first series regulator, and the lower one is the second series regulator.
[0042]
FIG. 3 is a circuit diagram showing a configuration example of a transformer winding used in the present invention. The winding on the left side of the transformer in FIG. 3 is on the primary side, and can be input from an AC power supply having an effective value of 100 V, 115 V, 200 V, and 230 V so as to comply with power supply standards around the world. In the case of using an AC having an effective value of 100 V, the terminals 19b and 20b and the terminals 19c and 20c in FIG. 3 are connected, the primary coils 19 and 20 are connected in parallel, and 100 V AC is applied to the primary coils. The maximum alternating current that can be applied to a single coil can be twice as large as that when one coil is used. When applying an AC having an effective value of 115 V, the terminals 19 a and 20 a and the terminals 19 c and 20 c are similarly connected to connect the primary coils 19 and 20 in parallel, and to apply an AC 115 V to this. When applying an AC having an effective value of 200 V, the terminals 19c and 20b in FIG. 3 are connected to connect the primary coils 19 and 20 in series, and an AC of 200 V is applied between 19b and 20c. When applying an AC having an effective value of 230 V, the terminals 19c and 20a in FIG. 3 are connected to connect the primary coils 19 and 20 in series, and an AC 230 V is applied between 19a and 20c. In this way, the effective value of the output AC voltage appearing on the secondary side of the transformer can always be made substantially equal using the same transformer shown in FIG. In order to enable the above-mentioned usage, in FIG. 3, the primary coils 19 and 20 are manufactured by winding the windings having the same length and the same number of windings in the normal winding or bifilar winding, and the terminals 19b and 20b are respectively formed. The coil is tapped from the point of equal number of turns equal to that of the terminal.
[0043]
The winding on the right side of the transformer in FIG. 3 is the secondary side, and is basically manufactured on the assumption that the AC output of the four secondary coils 21, 22, 23, and 24 is applied to the inputs of the two series regulators. Have been. In the secondary coil, each coil is manufactured by winding an equal-length winding with the same number of windings as a normal winding or a bifilar winding, and connecting two coils in parallel so that twice as much current as when using one coil can be taken out. . When a high voltage is required as the output of the series regulator, two coils can be connected in series to take out an alternating voltage twice as high as when one coil is used. By using the transformer of FIG. 3, it is possible to realize a series regulator that supports a wide range of DC output voltage while suppressing heat loss.
[0044]
In FIG. 2, since the first series regulator and the second series regulator have exactly the same block configuration, only the first series regulator will be described. A general rectifier circuit composed of a rectifier bridge diode and a smoothing capacitor is used as the rectifier circuit 1 indicated by 3 in FIG. 2, and the input AC voltage is subjected to full-wave rectification and smoothed DC voltage having a large ripple component. Is output from this rectifier circuit. The output DC voltage value substantially corresponds to the peak value of the input AC voltage.
[0045]
The DC output of the rectifier circuit 1 of FIG. 2 is input to the current control circuit 1 of 4. The current control circuit 1 in FIG. 2 is a circuit having a function of increasing or decreasing the value of a current flowing between the nodes 4a and 4b in accordance with a control signal applied to the node 4c. FIG. 4 shows an embodiment of the current control circuit 1 in FIG. In FIG. 4, a current control element in which the transistor Q1 and the transistor Q2 are Darlington connected is used, and the ratio of the control signal current applied to the node 4c to the current flowing from the node 4a to the node 4 and the current amplification factor are increased. Thereby, the amplification factor of the negative feedback control is increased to improve the ripple voltage compression ratio. Resistors R1 and R2 supply a bias voltage to transistors Q1 and Q2. Since heat loss proportional to the voltage difference between the node 4a and the node 4b occurs in the transistor Q1, Q1 is mounted on a radiator having an appropriate heat capacity. In FIG. 4, when the current flowing through the node 4c increases, the current flowing between the node 4a and the node 4b also becomes a current control circuit that operates in a proportional relation having a positive coefficient that increases according to the rate of change. .
[0046]
Although a PNP transistor is used for Q1 and Q2 in FIG. 4, when the NPN transistor is used to change the circuit to a type in which the collector is connected to the node 4a and the emitter is connected to the node 4b, the output current is emitter-follower type. It takes out form. In this case, it is necessary to set the potential of the control signal applied to the node 4c to be higher than the node 4b by about 1.2 V. Since the bias voltage of the node 4c is supplied from the node 4a, this means that a potential difference of 1.2 V or more always occurs between the node 4a and the node 4b, and the PNP transistor shown in FIG. Power loss can be greater than in a circuit. For the above reason, the embodiment of FIG. 4 employs a PNP transistor.
[0047]
In FIG. 2, the DC current output from the node 4b is input to the overcurrent limiting circuit 1 of 5. The overcurrent limiting circuit is a circuit for preventing a current larger than an arbitrarily set current value from flowing and will be described later in detail. The DC output via 5 is connected to a load via a positive voltage output terminal 1 at 6 and a ground terminal 1 at 7. Since the potential difference generated between the load terminals, that is, approximately between 6 and 7, is determined by the output current value and the impedance of the load according to Ohm's law, the potential difference, that is, the output voltage is stabilized by controlling the output current according to this potential difference. It is possible to do. In FIG. 2, eight comparison voltage generation circuits 1 and nine reference voltage generation and voltage comparison circuits 1 are provided for performing the stabilization control as described above.
[0048]
FIG. 5 shows one embodiment of the reference voltage generation and voltage comparison circuit 1 of the eight comparison voltage generation circuits 1 and 9 in FIG. In FIG. 5, the comparison voltage generation circuit 1 includes a variable resistor VR1. As shown in FIG. 2, an output voltage is applied between nodes 8b and 8c, and a voltage obtained by dividing the output voltage at a ratio arbitrarily set by VR1 is output from node 8a. It is applied to the input node 9a of the comparison circuit. IC1 in FIG. 5 is a shunt regulator and applies a high-precision reference voltage between 9d and 9b. Resistor R3 is connected to a constant DC potential V1 and supplies a bias voltage to Q3 and IC1.
[0049]
In the embodiment of FIG. 5, the voltage comparison circuit is realized by a differential amplifier circuit composed of transistors Q3 and Q4 and a resistor R4. Since a constant current determined by the resistance value of R4 flows between the node 9e and the node 9b, the voltage Vc applied to 9a from VR1 is lower than the reference voltage Vs applied from IC1 to the node 9d in FIG. When it is high, the emitter current of Q4 increases, and the emitter current of Q3 decreases accordingly. Conversely, when the reference voltage Vs is higher than Vc, the emitter current of Q4 decreases, and the emitter current of Q3 increases accordingly. The emitter current of Q3 is substantially equal to the collector current, and the collector of Q3 is connected from node 9c to node 4c in FIG. Therefore, in the circuit in which the current control circuit of FIG. 4 and the voltage comparison circuit of FIG. 5 are connected as shown in FIG. 2, when the DC output voltage of the first series regulator increases for some reason, the control current flowing to the node 4c decreases. As a result, the current value output from the node 4b decreases, the output voltage decreases according to Ohm's law, and the negative feedback control loop operates. It is also possible to use a Darlington connection type transistor having a higher current amplification factor than a normal transistor for Q3 and Q4.
[0050]
FIG. 6 is a block circuit diagram showing only an example necessary for the description of an embodiment when a remote sensing circuit is added to the first series regulator in FIG. The remote sensing circuit is connected to the power output terminals 6 and 7 in FIG. 6 and both ends of the load by long cables, and is generally used when a large current needs to flow to the load. Under the above-described situation, a voltage drop of a non-negligible magnitude occurs between the positive voltage output terminal 6 and the node 25b in FIG. 6, and between the ground terminal 1 and the node 25c in FIG. 8, the difference between the output voltage between the node 8b and the node 8c referenced by the comparison voltage generation circuit 1 and the output voltage actually generated at both ends of the load increases, so that an accurate stabilized voltage can be applied to the load. It will be difficult. Therefore, in FIG. 6, the ground nodes 8c and 9 of the reference voltage generation circuit 8 and the reference node 9b of the voltage comparison circuit 1 are separated from the output ground line and connected to the ground terminal 25b of the load. 8b is separated from the positive voltage output line and connected to the positive voltage application side terminal 25a of the load to form a remote sensing circuit. By connecting as shown in FIG. 6, it is possible to apply the voltage generated at both ends of the load 25 almost exactly to the comparison voltage generating circuit 1 of 8 and to stabilize the voltage across the load.
[0051]
FIG. 7 illustrates one embodiment of the overcurrent limiting circuit 1 of FIG. In FIG. 7, an output current flows from the node 5b toward the node 5c. At this time, a voltage drop occurs at both ends of the resistor R5 and heat loss is generated accordingly. Therefore, a resistor having an extremely small resistance value is used for R5. I do. Since a voltage substantially equal to the voltage between both ends of the voltage R5 is applied to both ends of the resistor R7 by the operational amplifier IC2, a current I1 proportional to the output current flows from the node 5e toward the node 5c. . In FIG. 7, IC3 outputs a constant high potential to node 5f with respect to node 5b. Therefore, the constant current I2 always flows from the node 5f to the node 5e via R9. As described above, when I2 is larger than I1, the potential of the node 5g becomes lower than the node 5b, so that the transistor Q5 is turned off. When the output current increases beyond a certain set current value, I1 becomes larger than I2 and the potential of node 5g becomes higher than node 5b, so that transistor Q5 is turned on. Transistor Q6 functions as a current gate that is turned on when Q5 is on, and its output current is output from node 5a and input to the line connecting node 9a and node 8a as shown in FIG. Therefore, when an output current exceeding an arbitrary set value flows between the node 5b and the node 5c, a current flows from the node 5a to the node 8c in FIG. 5, and the voltage applied to the node 9a increases. The current flowing through the node 9c decreases. Thus, the control current flowing to node 4c in FIG. 4 decreases, and the output current output from node 4b decreases. This operation is continued until I1 in FIG. 7 decreases to I2 or less and the transistor Q5 is turned off. Therefore, the overcurrent limiting circuit 1 in FIG. 2 according to the embodiment of FIG. 7 changes the output voltage so that the output current becomes substantially equal to the set current value when the output current exceeds an arbitrary set current value. The operation is continued until the power supply is reduced and lowered.
[0052]
In the two-output series regulator shown in FIG. 2 having two independent outputs, there is no potential relationship between the two series regulators, and the entire circuit of FIG. 2 is housed in one housing and both series regulators have the same temperature. If it is under the environment, prepare a separate overheat protection circuit for each series regulator and stop the operation of the circuit connected to the secondary side of the transformer when it overheats. It is possible to perform the overheat protection operation by using either the method of switching the side circuit or the method of stopping the operation of the secondary circuit of both series regulators by overheat using a photocoupler or the like. .
[0053]
In the embodiment shown in FIG. 2, ten overheat protection circuits 1 are constituted by one thermostat. In this embodiment, a thermostat that is normally closed and opened in an environment at a temperature equal to or higher than a set temperature is used. At this time, in a high temperature condition exceeding the set temperature in FIG. 2, the node 4c is opened and the control current does not flow through the current control circuit 1 in FIG. 2 at all, so that the output current taken out from the node 4b becomes zero and the first series. The regulator will stop operating.
[0054]
FIG. 14 is a layout diagram showing an embodiment of a solder surface pattern layout near input / output terminals of a double-sided printed circuit board for a series regulator according to the present invention. In FIG. 14, reference numeral 34 denotes a four-terminal input / output connector attached to the board component surface, reference numeral 35 denotes a rectifying bridge diode attached to the board component surface, and reference numeral 36 denotes a smoothing electrolytic capacitor attached to the board component surface. is there. Numeral 38 indicates the outer shape of the double-sided printed circuit board. The thick solid line in FIG. 14 indicates a portion where the copper foil is removed from the solder surface. In the present embodiment, the ground pattern is maximized to be a solid ground in order to improve noise characteristics, and the terminals 34a, 34b, 34d, 35a, 35b, 35c, and 36b that are not grounded have a separator as a slit for insulation. The terminals 34c, 35d and 36a to be grounded are provided with thermal pads for easily melting the solder as shown in FIG. In FIG. 14, the white portion on the substrate is generally covered with copper foil and forms a ground pattern. A slit 37 surrounds the rectifier circuit between the pattern to which the ground terminal 34c of the stabilized DC output is connected and the pattern to which the ground terminal 35d of the rectifier bridge diode and the ground terminal 36a of the smoothing electrolytic capacitor are connected. Is provided. During the rectification operation, the smoothing electrolytic capacitor frequently repeats charging and discharging, and accordingly, a considerable ripple current flows into and out of the capacitor terminals 36a and 36b. For this reason, a slit 37 is provided around the ground pattern of the rectifier circuit as shown in FIG. By doing so, the effect of the voltage drop due to the ripple current in the rectifier circuit on the DC stabilization circuit is reduced.
[0055]
FIG. 8 is a block circuit diagram of one embodiment in which the tracking type series regulator according to claim 1 is realized by modifying the two-output series regulator shown in FIG. The ground line of the first series regulator and the positive voltage output line of the second series regulator have a common reference potential, ie, a potential of 0 V, by connecting the nodes 7a and 14a. In the tracking type series regulator, since the two series regulators have a common reference potential, the operation of both series regulators can be electrically switched by the overheat protection circuit 31 as shown in FIG. Become. A portion configured by blocks 26, 27, 28, 29, and 30 shown on the right side of FIG. 8 is a circuit that realizes the tracking operation according to claim 1.
[0056]
FIG. 9 shows an embodiment of a tracking control circuit composed of blocks 26, 27, 28, 29 and 30 on the right side of FIG. The output voltage dividing circuit 26 in FIG. 8 is constituted by resistors R15 and R16 in FIG. The output voltage of the positive voltage power supply is applied between 6 and 7 in FIG. 9, and a voltage obtained by dividing the output voltage by R15 and R16 appears at the node 26c. If resistors having the same temperature coefficient are used for R15 and R16, fluctuations in the voltage division ratio due to a change in temperature can be suppressed. The current-to-voltage conversion circuit 28 in FIG. 8 is constituted by the resistor R17 in FIG. 9, the current control circuit 3 in 29 in FIG. 8 is constituted by the field effect transistor Q7 in FIG. The voltage conversion circuit 2 is configured by the resistor R18 in FIG. 9, and the voltage comparison circuit 3 in FIG. 8 is configured by the operational amplifier IC4 in FIG.
[0057]
In FIG. 9, 6 is connected to the positive voltage output of the positive voltage power supply, and 15 is connected to the ground potential of the negative voltage power supply, that is, the negative voltage output. Therefore, a current flows from the node 28a toward the node 30b, and this current value is controlled according to the gate voltage of Q7. The operational amplifier IC4 in FIG. 9 outputs a voltage obtained by amplifying the potential difference between the node 28b and the node 26c from the node 27a and applies the voltage to the gate 29a of Q7. Accordingly, the magnitude of the current flowing between nodes 28a and 30a is controlled such that the voltage drop generated at R17 becomes equal to the potential difference between nodes 26a and 26c. This current is converted by R18 into a voltage having a potential with respect to the node 30a, that is, the ground line of the negative voltage power supply, and output from the node 30c. By using resistors having the same temperature coefficient for R17 and R18, it is possible to suppress a change due to a temperature change in a ratio of a potential difference between the nodes 28a and 28b and a potential difference between the nodes 30a and 30b.
[0058]
As described above, the voltage output between nodes 30c and 15 in FIG. 9 is equal to the potential difference between both ends of R15. In the embodiment of FIG. 9, the voltage is one half of the output voltage of the positive voltage power supply. Is equal to FIG. 10 shows an embodiment of the voltage comparison circuit 2 of 17 in FIG. 8, which is composed of substantially the same circuits and components as the voltage comparison circuit shown in FIG. In FIG. 5, the reference voltage Vs is applied to the input node 9d of the voltage comparison circuit by the IC1, whereas in FIG. 10, the voltage output from the node 30c in FIG. The only difference is that the reference voltage is applied to the input node 17d. As mentioned above, the reference voltage is always kept equal to one half of the output voltage of the positive voltage power supply, and in the embodiment of FIG. 10, the output voltage of the negative voltage power supply changes at the same rate when the reference voltage changes. As a result, the output voltage of the negative voltage power supply changes at the same rate as the change of the output voltage of the positive voltage power supply. By adjusting the variable resistor VR2 in FIG. 10, the tracking operation can be realized such that the output voltage of the negative voltage power supply has the same absolute value as the output voltage of the positive voltage power supply. The same printed circuit board pattern layout is used in the present embodiment for the voltage comparison circuits of FIG. 5 and FIG. 10, and it can be easily realized on the same printed circuit board as a series regulator having two independent outputs or a tracking series regulator. It is possible to do.
[0059]
FIG. 11 shows an embodiment of the overheat protection circuit 3 of FIG. The node 31a in FIG. 11 is connected to the negative voltage output terminal 15 in FIG. 8 and has a potential equal to the negative voltage output. In FIG. 11, resistors R20 and R21 supply a bias voltage for transistor Q10. The thermostat T1 in FIG. 11 is normally closed and is open under high temperature conditions. Therefore, in FIG. 11, Q10 is normally kept in the OFF state, and Q10 is turned on at high temperature. At this time, current flows from the nodes 31b and 31c toward the collector of Q10. The node 31c is connected to the node 5d of the overcurrent limiting circuit 1 in FIG. 8 and the transistor Q10 is turned on, and the current flows from the node 5d to the node 31c shown in FIG. The transistor Q6 in FIG. 7 is turned on. Therefore, at this time, the operation control is performed in the direction of decreasing the output current as described above, and as a result, the output current becomes zero, the operation of the positive voltage power supply is stopped, and the overheating state is protected. Similarly, on the negative voltage power supply side, in a state where a current flows from the node 13d to the node 31b of the overcurrent limiting circuit 2 in FIG. 8, the control for reducing the output current operates, and the operation of the negative voltage power supply stops. As described above, the two series regulators can be simultaneously stopped during the tracking operation using the overheat protection circuit of FIG. 11 to protect the overheated state.
[0060]
FIG. 15 is a connection diagram showing one embodiment of connection near the input / output terminal on the housing of the series regulator according to the present invention. The four-terminal input / output connector 34 on the printed circuit board of the series regulator and the four-terminal input / output terminal board 40 on the housing are connected by a harness. In FIG. 15, an electrolytic capacitor 41 is directly connected between the positive electrode 40d and the negative electrode 40c of the stabilized DC output terminal on the housing at the shortest distance. The electrolytic capacitor 41 reduces noise mixed on the harness and on the cable connected to the output terminals 40c and 40d outside the housing, thereby improving the noise and ripple characteristics of the stabilized output voltage of the series regulator.
[0061]
(Second Embodiment) In the present embodiment for increasing the ripple compression ratio, reducing the number of parts and reducing the cost, the voltage comparison circuit is realized by the differential amplification method in FIG. In the step 5, the shunt regulator of the IC 1 used only for the purpose of generating the reference voltage is changed to operate to perform both functions of generating the reference voltage and comparing the voltage. FIG. 12 is a circuit diagram of a portion of the reference voltage generation and voltage comparison circuit 1 of the comparison voltage generation circuits 1 and 9 of FIG. 2 in FIG. 2 in the present embodiment, that is, a portion corresponding to FIG. 5 of the present embodiment. As can be seen by comparing FIG. 5 and FIG. 12, in the present embodiment, Q4 is deleted, and the cost can be reduced as compared with the first embodiment. The shunt regulator of IC1 has a REF terminal, and can perform an operation of flowing between the anode and the cathode a current proportional to an error between a voltage applied to the REF terminal and a reference voltage in the shunt regulator. When the REF terminal is connected to node 9a as shown in FIG. 12, the comparison voltage applied from VR1 is compared with the high-precision reference voltage inside IC1, and a current corresponding to the error flows from node 9d to node 9b. The DC output of the first series regulator is subjected to negative feedback control through a process in which the bias state of Q3 changes, and as a result, the value of the control current flowing to the node 9c changes. Since there is only a slight difference between the circuits of FIGS. 5 and 12, the present embodiment and the first embodiment can be realized by using a common printed circuit board pattern.
[0062]
(Third Embodiment) Next, in the above embodiment, a thermostat having both a temperature detection and a switching function is used as a temperature detection element of the overheat protection circuit. However, in this embodiment, the temperature is detected by a temperature detection resistor. By performing switching by an electronic circuit, the overheat protection circuit 3 of FIG. 8 is configured, and it is possible to stop the operation of the two power supplies in the tracking series regulator. FIG. 13 is a circuit diagram of the overheat protection circuit 3 of FIG. 8 in the present embodiment. In FIG. 13, TR1 is a temperature detecting resistor, that is, an element whose resistance value changes with temperature. TR1 sets a resistance value of the resistor R24 equal to the resistance value shown under an arbitrary set temperature environment, and amplifies a potential difference between both ends of a bridge formed by R22, R23, R24, and TR1 by an operational amplifier IC5. The transistor Q11 is switched by the output of. When overheated, the transistor Q11 is turned on and current flows through the nodes 31b and 31c, and the same overheat protection operation as the overheat protection circuit using the thermostat shown in FIG. 11 in the first embodiment is performed. Is
[0063]
【The invention's effect】
According to the present invention implemented as described above, it becomes possible to perform a tracking operation by making a minimum change to two series regulator circuits composed of substantially the same circuit and components, and to realize a common printed circuit board. Has made it possible to produce a two-output series regulator and a tracking type series regulator. The tracking series regulator according to the present invention has the following advantages as compared with the conventional tracking series regulator.
[0064]
Whereas conventional tracking type series regulators use semiconductor elements having different polarities in the positive and negative series regulator circuits, the present invention employs substantially the same circuit to form the positive and negative series regulators, so there are fewer components than before. This can be realized in points, which is advantageous in terms of parts inventory management and parts purchasing costs.
[0065]
At the time of failure / repair, inspection and confirmation should be performed for two series regulator circuits of the same operation, so that inspection can be completed in a shorter time than a conventional tracking type series regulator where positive and negative series regulators are different circuits. Also, the number of stock parts for repair can be reduced to a smaller number than in the past, so that the cost can be reduced.
[0066]
The tracking control method according to the present invention realizes tracking control having excellent temperature characteristics at a lower cost than the conventional tracking type series regulator by using resistors having the same temperature coefficient in the voltage dividing circuit and the current-voltage conversion circuit. It is possible.
[0067]
Using the same circuit, components and common printed circuit board as the tracking type series regulator in the present invention, it is also possible to constitute a series regulator having two independent independent outputs with almost no change. For this reason, the same circuit board can meet a wider demand for power supplies than before, which is advantageous in terms of production cost.
[0068]
The series regulator incorporated in the tracking type series regulator in the present invention has been reduced in ripple and noise by a plurality of technologies described in the embodiments, and has been standardized as a circuit block. It is also possible to easily configure a low-ripple, low-noise product that meets the specifications required by the user.
[0069]
Further, a low-cost and simple method for performing a tracking operation of a stabilized power supply composed of two independent same circuits and components with a minimum change implemented in the present invention is described in the embodiment of the present invention. The first and second series regulators can be easily replaced with the first and second switching regulators to easily change the dual output switching regulator to operate as a tracking type switching regulator at low cost. . A circuit block that controls the output voltage in a general switching regulator circuit is a PWM controller. In order to supply a control signal to the PWM controller, the switching regulator divides the reference voltage and the output voltage in the same manner as a series regulator. A voltage comparison circuit for comparing the applied voltages is used. Therefore, in the tracking control method according to the present invention shown in FIG. 1, the tracking type switching regulator is replaced by replacing the 32 first series regulators with the first switching regulator and the 33 second series regulators with the second switching regulator. Can be realized.
[Brief description of the drawings]
FIG. 1 is a block circuit diagram showing a tracking control method.
FIG. 2 is a block circuit diagram showing one embodiment of a two-output series regulator according to the present invention.
FIG. 3 is a circuit diagram of a general-purpose power transformer capable of supporting a wide range of input AC voltage and output AC voltage according to the present invention.
FIG. 4 is a circuit diagram showing an embodiment in which a current control circuit used in a series regulator according to the present invention is configured by Darlington-connected transistors.
FIG. 5 is a circuit diagram showing one embodiment of a comparison voltage generation circuit and a reference voltage generation and voltage comparison circuit used in the series regulator according to the present invention.
FIG. 6 is a circuit diagram showing one embodiment of a remote sensing circuit used in the series regulator according to the present invention.
FIG. 7 is a circuit diagram showing an embodiment of an overcurrent control circuit used in a series regulator according to the present invention.
FIG. 8 is a block circuit diagram showing an embodiment of a tracking type series regulator according to the present invention.
FIG. 9 is a circuit diagram showing one embodiment of a tracking control circuit used in the tracking type series regulator according to the present invention.
FIG. 10 is a circuit diagram showing one embodiment of a voltage comparison circuit of a controlled side series regulator used in the tracking type series regulator according to the present invention.
FIG. 11 is a circuit diagram showing an embodiment of an overheat protection circuit using a thermostat used in a tracking series regulator according to the present invention.
FIG. 12 is a circuit diagram showing an embodiment in which a reference voltage generation and voltage comparison circuit used in a series regulator according to the present invention is configured by a shunt regulator.
FIG. 13 is a circuit diagram showing an embodiment of an overheat protection circuit using a temperature detection resistor used in the tracking series regulator according to the present invention.
FIG. 14 is a pattern layout diagram showing one embodiment of a rectifier circuit of a double-sided printed circuit board and a solder surface pattern of a stabilized DC output portion used in the series regulator according to the present invention.
FIG. 15 is a block circuit diagram showing one embodiment of connection of an electrolytic capacitor to a stabilized DC output terminal on a casing used in a series regulator according to the present invention.
[Explanation of symbols]
1 Commercial AC power supply
2 transformer
2a, 2b Primary coil of 2 transformer
2c, 2d 2 transformer secondary coil
3 Rectifier circuit for first series regulator
4. Output current control circuit for the first series regulator
4a DC input node to current control circuit of 4
4b DC output node from current control circuit of 4
4c 4 Control signal input node to current control circuit
5 Overcurrent limiting circuit for the first series regulator
5a 5 Control signal output node of overcurrent limiting circuit
5b DC input node to 5 overcurrent limiting circuit
5c DC output node from overcurrent limiting circuit of 5
6 Positive voltage output terminal for first series regulator
7 Ground output terminal for first series regulator
8 Comparison voltage generator for first series regulator
8a Comparison voltage output node of comparison voltage generation circuit of 8
8b 8 Positive voltage input node of comparison voltage generation circuit
8c 8 Ground potential input node of comparison voltage generation circuit
9. Reference voltage generation and voltage comparison circuit for first series regulator
9a Comparison voltage input node to voltage comparison circuit 9
9b 9 Reference voltage generation and ground potential input node to voltage comparison circuit
9c Control signal output node from voltage comparison circuit 9
10. Overheat protection circuit for the first series regulator
11 Rectifier circuit for second series regulator
12. Output current control circuit for second series regulator
13 Overcurrent limiting circuit for second series regulator
14 Positive voltage output terminal for second series regulator
15 Ground output terminal for second series regulator
16 Comparison voltage generation circuit for second series regulator
17. Reference voltage generation and voltage comparison circuit for second series regulator
18 Overheat protection circuit for the second series regulator
19 First primary coil of general-purpose transformer
19a Input terminal a to the primary coil 19
19b Middle tap b of 19 primary coil
19c Input terminal c to 19 primary coil
20 Second primary coil of general-purpose transformer
20a Input terminal a to the primary coil of 20
20b Middle tap b of the primary coil of 20
20c Input terminal c to the primary coil of 20
21 First secondary coil of general-purpose transformer
21a Output terminal a from the secondary coil of 21
21b Output terminal b from the secondary coil of 21
22 Second secondary coil of general-purpose transformer
22a Output terminal a from the secondary coil of 22
22b Output terminal b from the secondary coil of 22
23 Third secondary coil of general-purpose transformer
23a Output terminal a from the secondary coil of 23
23b Output terminal b from the secondary coil of 23
24 Fourth secondary coil of general-purpose transformer
24a Output terminal a from the secondary coil of 24
24b Output terminal b from the secondary coil of 24
PNP transistor on the output stage side in the Darlington connection type current control circuit of Q14
Output stage PNP transistor in the Darlington connection type current control circuit of Q24
R1, R2 Two resistors to supply bias voltage to Q1 and Q2
Variable resistor for dividing an input voltage in a VR18 comparison voltage generation circuit
NPN transistor on the reference voltage input side in the differential amplification type voltage comparison circuit of Q39
NPN transistor on the comparison voltage input side in the differential amplification type voltage comparison circuit of Q49
R3 Resistor for supplying bias voltage to IC1 and Q3
A resistor for adjusting a constant current value in a differential amplification type voltage comparison circuit of R49.
IC1 Shunt regulator for generating reference voltage
Vs Reference voltage value applied from IC1
Vc Comparison voltage value applied from node 9a
9d 9 Reference voltage application node of voltage comparison circuit
9e Node to which emitter of differential amplification transistor is connected
DC power supply having a positive potential with respect to the ground terminal of V17
25 Load connected to the output of the first series regulator
25a Positive voltage input terminal of 25 load
25b Ground voltage input terminal for 25 load
Current detection resistor in the overcurrent limiting circuit of R55
R6 + input side resistor of IC2
R7 IC2-input side resistor
R8 IC2 output voltage setting resistor
R9 Constant current supply resistor to node 5e
R10, R11 Q5 bias voltage setting resistor
R12, R13 Q6 bias voltage setting resistor
R14 Control output current setting resistor to node 5a
Switching NPN transistor in the overcurrent limiting circuit of Q55
Switching PNP transistor in the overcurrent limiting circuit of Q65
IC2 Voltage error amplification operational amplifier
IC3 constant voltage generation circuit
I1 Current flowing from node 5e to node 5c
I2 Current flowing from node 5f to node 5e
5d Input connection node from overheat protection circuit used when operated as tracking type series regulator
5e-input node of operational amplifier IC2
5f Node having a constant positive potential with respect to node 5b
Output node of 5g operational amplifier IC2
DC power supply having a positive potential with respect to the ground terminal of V27
7a 7 Connection Node to Ground Line of First Series Regulator of 7
13a Control signal output node of 13 overcurrent limiting circuit
14a Connection node to the positive voltage output line of the second series regulator of 14
16a Comparison voltage output node of 16 comparison voltage generation circuits
16b Positive voltage input node of 16 comparison voltage generation circuit
16c 16 ground potential input node of comparison voltage generation circuit
17a Comparison voltage input node to voltage comparison circuit 17
17b Ground potential input node to voltage comparison circuit 17
17c Control signal output node from voltage comparison circuit 17
17d Reference voltage input node to 17 voltage comparison circuit
26 Circuit that divides input voltage and outputs it
26a Positive voltage input node to voltage divider circuit 26
26b Ground voltage input node to voltage divider circuit 26
26c Divided voltage output node of the voltage divider circuit of 26
27 Circuit that compares and amplifies the difference between two input voltages and outputs the result
27a Output Node of Voltage Comparison Circuit of 27
27b First voltage input node to voltage comparison circuit of 27
27c A second voltage input node to the voltage comparison circuit of 27
28. A first current-to-voltage conversion circuit that outputs a voltage proportional to an input current
28a Current input node of current-voltage conversion circuit of 28
28b Voltage output node of current-voltage conversion circuit of 28
28c Current output node of current-voltage conversion circuit of 28
29 Current control circuit that increases / decreases current flowing according to control input
29a Control signal input node of current control circuit of 29
29b Current output node of current control circuit of 29
29c Current input node of 29 current control circuit
30 A second current-voltage conversion circuit that outputs a voltage proportional to an input current
30a 30 Current input node of current-voltage conversion circuit of 30
30b Current output node of current-to-voltage conversion circuit of 30
30c Voltage output node of current-voltage conversion circuit of 30
31 Overheat protection circuit for tracking regulator
31a Ground voltage input node of the overheat protection circuit of 31
31b A first control signal output node of the overheat protection circuit of 31
31c The second control signal output node of the overheat protection circuit of 31
Two voltage dividing resistors in the voltage dividing circuit of R15 and R16 26
Resistor in the current-voltage conversion circuit of R17 28
A resistor in the current-voltage conversion circuit of R18 30
Field effect transistor in current control circuit of Q729
Operational amplifier in the voltage comparison circuit of IC427
Variable resistor that divides input voltage by VR2 16 comparison voltage generation circuit
NPN transistor on the reference voltage input side in the differential amplification type voltage comparison circuit of Q817
NPN transistor on the comparison voltage input side in the differential amplification type voltage comparison circuit of Q917
Resistor for adjusting the constant current value in the differential amplification type voltage comparison circuit of R1917
DC power supply having a positive potential with respect to the ground potential of the second series regulator of V315
R20, R21 Q10 bias voltage setting resistor
NPN transistor which performs switching operation by the overheat protection circuit of Q10 31
T1 Thermostat that closes at room temperature and opens at temperatures higher than the set temperature
DC power supply having a positive potential with respect to the ground potential of the second series regulator of V415
TR1 Temperature detection resistor
R22, R23 Two resistors for bridge configuration
R24 Resistor with the same resistance value as TR1 under set temperature
R25, R26 Input resistor for operational amplifier IC5
R27 IC5 feedback resistor
R28, R29 Q11 bias voltage setting resistor
Output current setting resistor of the overheat protection circuit of R30 31
Switching transistor in overheat protection circuit of Q11 31
D1 Diode that blocks current going to the output of IC5
IC5 Operational amplifier that compares the potential difference between both ends of the bridge
DC power supply having a positive potential with respect to the ground potential of the second series regulator of V515
32 1st series regulator
33 Second Series Regulator Modified to Input External Reference Voltage When Operated as Tracking Type Series Regulator
34 4-terminal I / O connector mounted on board component surface
34a AC voltage input terminal 1
34b AC voltage input terminal 2
34c Stabilized DC output ground terminal. It is connected to the ground pattern on the solder surface of the substrate via the thermal pad.
34d stabilized DC positive voltage output terminal
35 Rectifier bridge diode mounted on board component side
35a Rectifier bridge diode positive voltage output terminal
35b AC voltage input terminal 1 for rectifier bridge diode
35c AC voltage input terminal 2 of rectifier bridge diode
35d Ground terminal for rectifier bridge diode. It is connected to the ground pattern on the solder surface of the substrate via the thermal pad.
36 Smoothing electrolytic capacitor mounted on board component surface
36a Negative terminal of a smoothing electrolytic capacitor. It is connected to the ground pattern on the solder surface of the substrate via the thermal pad.
36b Positive terminal of electrolytic capacitor for smoothing
37 Rectifier circuit ground pattern and stabilized DC output ground pattern
Slit separating Both are connected by a narrow copper foil portion without a slit at the lower left in FIG.
38 Part of the outline of the printed circuit board for the regulator
39 series printed circuit board for regulator
4 terminal input / output terminal board mounted on 40 series regulator housing
40a AC voltage input terminal 1 of input / output terminal board
40b AC voltage input terminal 2 of input / output terminal board
40c I / O terminal board stabilized DC output negative terminal
40d I / O terminal board stabilized DC output positive terminal
41 Electrolytic capacitor for noise removal

Claims (1)

In a two-output series regulator including first and second independent series regulators, a ground terminal of the first series regulator is connected to a positive voltage output terminal of the second series regulator, and this is newly reset to zero. A positive / negative two-output series regulator having a potential output terminal, a positive voltage output terminal of the first series regulator being a positive voltage output terminal, and a ground terminal of the second series regulator being a negative voltage output terminal; A third current control means for providing a signal line connecting between the negative voltage output terminals and controlling a current flowing through the signal line; a first and a second current converting the current flowing through the signal line into a voltage; A voltage conversion circuit, an output voltage division circuit for generating a voltage proportional to a positive voltage output, an output voltage of the first current-to-voltage conversion circuit, A first series comprising a third voltage comparison circuit for comparing an output voltage of a voltage division circuit, wherein the third current control means is controlled by an output of the third voltage comparison circuit to output a positive voltage The current flowing through the signal line is increased or decreased in proportion to the output voltage of the regulator, and the current flowing through the signal line is converted into a voltage by the second current-to-voltage conversion circuit. A two-output series regulator having a tracking function in which a positive output voltage and a negative output voltage change in synchronization with each other, wherein the two output regulators are used as a reference voltage input to a voltage comparison circuit in the second series regulator. That is, a tracking type series regulator.

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