JP3578879B2 - Electric circuit device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric circuit device capable of adjusting respective circuits while being divided into a main board and a sub-board.
[0002]
[Prior art]
For example, when configuring a large-scale electric circuit such as an electric circuit of a magnetic recording / reproducing apparatus, a plurality of circuit boards are used in combination for the purpose of simplifying the handling of the circuit boards. .
[0003]
FIG. 7 is a block diagram showing an electric circuit of a conventional magnetic recording / reproducing apparatus, mainly showing a portion related to a power supply circuit.
[0004]
Here, the circuit board of the magnetic recording / reproducing apparatus is manufactured separately for the main substrate 1 and the sub-substrate 2, and is electrically connected between the main substrate 1 and the sub-substrate 2 by a lead wire or a connector. Thus, the magnetic recording / reproducing apparatus can be realized.
[0005]
In the figure, a main board 1 includes a reference voltage generation circuit 3, a power supply circuit 4, a control circuit 5, an audio circuit 6, and the like. Further, only the signal processing circuit 7 is formed on the sub-board 2.
[0006]
The reference voltage generating circuit 3 is a circuit including a Zener diode ZD for generating a reference voltage (5 V) in the power supply circuit 4. A constant voltage (between an anode and a cathode terminal of the Zener diode ZD) is generated by a current flowing therebetween. 5V). The power supply circuit 4 generates a power supply voltage (hereinafter referred to as SW5V) required to operate the audio circuit 6 of the main board 1 and the signal processing circuit 7 of the sub board 2 based on the reference voltage. 2 is supplied to the signal processing circuit 7 via the power supply line 8 and the connection terminals 8a and 8b. The control circuit 5 controls ON / OFF of the magnetic recording / reproducing device, and turns OFF / ON of the power supply circuit 4 in accordance with ON / OFF of the PWV bar signal output from the control circuit 5. Switching.
[0007]
The circuit board of the magnetic recording / reproducing apparatus configured as described above has various electric components such as transistors, resistors, coils, and capacitors on the substrate. The circuit must be set up to operate correctly. As electric components adjusted in these manufacturing steps, a variable resistor for adjusting the audio circuit 6 is provided on the main board 1, and a variable resistor for adjusting the signal processing circuit 7 is provided on the sub board 2. Is provided. Since these circuit adjustments are performed while checking the output signal to be adjusted with a measuring instrument or the like, the above-mentioned SW5V is supplied to each of the substrates 1 and 2, and the adjustment can be performed only when each circuit is operating. Become.
[0008]
However, since the sub-board 2 is not provided with a power supply circuit for independently generating the above-mentioned SW5V, it is not possible to perform single-circuit adjustment using the sub-board 2 as a single unit in the manufacturing process. The circuit adjustment had been carried out.
[0009]
In order to adjust the sub-substrate 2 alone, an external power supply circuit that generates a voltage equivalent to SW5V (hereinafter referred to as SW5V ′) is prepared and supplied to the signal processing circuit 7 from the connection terminal 8b. It is also possible to adjust. However, it is not easy to eliminate the difference between the generated voltage values of SW5V from the main substrate 1 and SW5V 'from the external power supply circuit. In particular, when the sub-substrate 2 has less tolerance for the variation in SW5V voltage than the main substrate 1, when the sub-substrate 2 is operated with SW5V 'and when the main substrate 1 and the sub-substrate 2 are combined, The circuit operation of the signal processing circuit formed on the sub-substrate 2 also differs. Therefore, unless the sub-board 2 is connected to the main board 1, accurate circuit adjustment may not be possible.
[0010]
[Problems to be solved by the invention]
As described above, according to the conventional electric circuit device, after the main board 1 and the sub board 2 are combined and attached to a predetermined board installation position in the final step of the manufacturing process, the variable resistance and the like of each board are adjusted. Needed. In other words, circuit adjustment cannot be performed in the middle of the manufacturing process, and must be performed in the final step where most products are completed, so electrical signals to be measured during circuit adjustment are taken out from each substrate, It was difficult to input to the measuring instrument. In addition, when the variable resistor is located at a position that is difficult to reach on the substrate, an adjustment error is likely to occur. Therefore, the conventional circuit adjustment method has a problem that the circuit adjustment procedure tends to be complicated, it takes time to start the circuit adjustment, and the number of defective adjustments increases. .
[0011]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide an electric circuit device that can simplify circuit adjustment and reduce time in a manufacturing process.
[0012]
[Means for Solving the Problems]
An electric circuit device according to the present invention includes a main board having a power supply circuit and a unit (hereinafter, referred to as a reference voltage generation unit) for generating a reference voltage of a voltage generated by the power supply circuit, and a power supply circuit of the main board. An electric circuit device comprising one or more sub-boards including a circuit driven by being connected to the sub-board, wherein the sub-board is provided with an external power supply circuit different from the power supply circuit of the main board. A connectable external terminal, comprising a power supply circuit of the main board or reference voltage generating means for a voltage supplied from the external power supply circuit, and in a state where the sub-board is separated from the main board, When a voltage is supplied from an external power supply circuit to perform simplex adjustment and the main board and the sub board are electrically connected, a power supply voltage is supplied from the main board to the sub board, and the sub board is It is obtained by configured to provide a reference voltage from the reference voltage generating means to the main board.
[0013]
In the electric circuit device according to a second aspect of the present invention, both the reference voltage generating means of the main substrate and the sub-substrate are constituted by zener diodes.
[0014]
According to a third aspect of the present invention, in the electric circuit device, the reference voltage generated on any one of the sub-substrates is set to be lower than the reference voltages of the other sub-substrates and the main substrate.
[0015]
The electric circuit device according to claim 4 of the present invention is provided with means for separating the reference voltage generation means from the power supply circuit on the main board, and after the electric circuit apparatus is configured by combining the main board and the sub-board, The reference voltage is supplied to the main substrate from one of the sub-substrates, and the reference voltage generating means of the main substrate is not electrically operated.
[0016]
The electric circuit device according to claim 5 of the present invention is a transistor which is turned off when the means for separating from the power supply circuit combines the main substrate and the sub-substrate.
[0017]
The electric circuit device according to claim 6 of the present invention is configured such that a part of the circuit board constituting the reference voltage generating means can be discarded when the main board and the sub-board are combined as means for separating from the power supply circuit. Things.
[0018]
An electric circuit device according to claim 7 of the present invention is a mechanical switch that can be turned off when the means for separating from the power supply circuit combines the main board and the sub-board.
[0019]
The electric circuit device according to claim 8 of the present invention is a flexible insulated wire capable of cutting a part of the reference voltage generating means when the main board and the sub-board are combined, as means for separating from the power supply circuit. It consists of.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a magnetic recording / reproducing apparatus will be described with reference to the accompanying drawings.
[0021]
Embodiment 1 FIG.
FIG. 1 shows a first embodiment of the present invention. The substrates of the electric circuit of the magnetic recording / reproducing apparatus are manufactured separately from the main substrate 1 and one or a plurality of sub-substrates 2, and lead wires or connectors are connected between the main substrate 1 and the sub-substrate 2 in the final step. By using the electrical connection, the magnetic recording / reproducing apparatus is completed.
[0022]
In FIG. 1, reference numeral 1 denotes a main board, on which a reference voltage generation circuit 3, a power supply circuit 4, a control circuit 5, an audio circuit 6, and the like are provided. In addition, on the sub-substrate 2, together with the signal processing circuit 7, a reference voltage generation circuit 9 necessary for adjusting the circuit of the sub-substrate 2 alone is formed. The reference voltage generation circuit 9 includes a zener diode ZD ′ that generates a reference voltage. The voltage between the terminals of the zener diode ZD of the reference voltage generation circuit 3 is equal to that of the reference voltage generation circuit 9 of the sub-substrate 2. The voltage is set higher than the voltage between terminals of the Zener diode ZD '. Therefore, when the main board 1 and the sub-board 2 are connected, the reference voltage generation circuit 9 generates a reference voltage for the power supply circuit 4. In FIG. 1, the same parts as those in FIG. 7 described as the conventional device are denoted by the corresponding reference numerals.
[0023]
Next, the operation of the electric circuit device configured as described above will be described.
[0024]
When adjusting the sub-board 2 alone, first, an external power supply circuit capable of generating a power supply voltage substantially equal to SW5V is prepared.
[0025]
FIG. 2 is a diagram showing the external power supply circuit 100 connected to the sub-board 2.
[0026]
This external power supply circuit 100 is connected to a bias external terminal 9a, a reference voltage output external terminal 9b, and a power supply voltage SW5V supply external terminal 8b of the reference voltage generation circuit 9, respectively. SW5V required by the sub-board 2 is generated from the reference voltage of the Zener diode ZD 'of the reference voltage generation circuit 9 and the power supply voltage of the external power supply circuit, and is supplied to the sub-board 2 by the connection terminal 8b. , The signal processing circuit 7 can be operated. Therefore, even if the sub-board 2 is used alone, the circuit adjustment of the signal processing circuit 7 using the SW5V becomes possible.
[0027]
In addition, since the voltage between the terminals of the zener diode ZD of the reference voltage generation circuit 3 on the main substrate 1 is set to be higher than the voltage between the terminals of the zener diode ZD ′ of the reference voltage generation circuit 9 on the sub-substrate 2, the main substrate 1 When the sub-board 2 and the sub-board 2 are connected as shown in FIG. 1, the reference voltage generation circuit 3 of the main board 1 does not operate, and only the reference voltage generation circuit 9 of the sub-board 2 generates a reference voltage.
[0028]
Note that the audio circuit 6 of the main board 1 can be independently adjusted by the reference voltage generation circuit 3 and the power supply circuit 4.
[0029]
As described above, in the electric circuit device described above, since each of the boards 1 and 2 can be adjusted independently, the circuit adjustment can be performed before the main board 1 and the sub board 2 are combined. Therefore, it becomes easy to take out an electric signal to be subjected to circuit adjustment from each of the substrates 1 and 2 and input the electric signal to a measuring instrument, and it becomes possible to operate a variable resistor or the like at a position easily accessible. Since there is no change in the magnitude of SW5V supplied to the sub-board 2 between the time of the circuit adjustment by itself and the case of the combination with the main board 1, the circuit adjustment for adjusting the circuit operation of the sub-board 2 The process can be simplified and the time can be shortened.
[0030]
In the above, the description has been made assuming that only one sub-board 2 is connected to the main board 1 to constitute an electric circuit device (magnetic recording / reproducing apparatus). When connecting to the main board, if the reference voltage generated by any one of the sub-boards is set lower than any of the reference voltages of the other sub-boards and the main board, the main board and each When the sub-substrates are combined, only the reference voltage generated by the one sub-substrate is supplied to each substrate.
[0031]
Embodiment 2 FIG.
In the electric circuit device according to the second embodiment shown in FIG. 3, unlike the first embodiment, a transistor 11 is connected in series to a Zener diode ZD as a circuit 10 for generating a reference voltage of the main substrate 1. That is, the collector of the transistor 11 is connected to the Zener diode ZD, and the emitter is grounded. The base of the transistor 11 is connected to the power supply circuit 4 and grounded when the external terminal 10a is connected to the external terminal 2a of the sub-substrate 2. Thereby, the same operation as that of the electric circuit device of the first embodiment is performed as described below.
[0032]
That is, when the sub-substrate 2 is individually adjusted, the external terminal 9a for the bias of the reference voltage generation circuit 9, the external terminal 9b for the output of the reference voltage, and the external terminal 8b for supplying the power supply voltage SW5V are shown in FIG. To the external power supply circuit 100 as described above. Thereby, the signal processing circuit 7 can be operated, and the circuit adjustment of the signal processing circuit 7 becomes possible even when the sub-board 2 is used alone.
[0033]
When the main substrate 1 is adjusted alone, a current flows from the power supply circuit 4 to the base of the transistor 11, and the transistor 11 is turned on. Therefore, the Zener diode ZD of the reference voltage generation circuit 10 is electrically connected to the ground. A reference voltage is generated in the Zener diode ZD.
[0034]
Further, when the main substrate 1 and the sub-substrate 2 are combined, the base of the transistor 11 is grounded via the external terminal 2a of the sub-substrate 2, so that the transistor 11 is turned off and the reference voltage generation circuit 10 The Zener diode ZD is insulated from the ground, and no current flows through the Zener diode ZD, so that no reference voltage is generated. That is, when the main board 1 and the sub-board 2 are combined, the reference voltage generating circuit 10 of the main board 1 does not operate, and only the reference voltage generating circuit 9 of the sub-board 2 generates the reference voltage. Therefore, as in the first embodiment, the individual adjustment of each substrate can be easily performed even in the middle of the manufacturing process, and when the circuit adjustment is performed by itself and when the main substrate 1 is combined. Since the magnitude of SW5V supplied to the sub-substrate 2 does not change, the process of adjusting the circuit can be simplified and the time can be shortened.
[0035]
Embodiment 3 FIG.
In the electric circuit device of the third embodiment shown in FIG. 4, the reference voltage generation circuit 12 of the main substrate 1 includes a substrate portion 13 in which a part of the circuit can be discarded, instead of the transistor of the second embodiment. In. However, before the substrate portion 13 is discarded, it is necessary to execute the single adjustment of the main substrate 1. In FIG. 4, the same reference numerals are given to the same parts as those in FIG. 3 described as the second embodiment.
[0036]
Next, the operation of the electric circuit device configured as described above will be described.
[0037]
First, when the sub-substrate 2 is individually adjusted, the external terminal 9a for the bias of the reference voltage generation circuit 9, the external terminal 9b for the output of the reference voltage, and the external terminal 8b for the supply of the power supply voltage SW5V are respectively shown in FIG. It is connected to the external power supply circuit 100 as shown. Thereby, the signal processing circuit 7 can be operated, and the circuit adjustment of the signal processing circuit 7 becomes possible even when the sub-board 2 is used alone.
[0038]
When the main substrate 1 is adjusted as a single unit, the substrate portion 13 forming a connection circuit between the zener diode ZD of the reference voltage generation circuit 12 and the ground establishes a conductive state between the zener diode ZD of the reference voltage generation circuit 12 and the ground. Therefore, a reference voltage is generated in the Zener diode ZD.
[0039]
Further, when the main substrate 1 and the sub-substrate 2 are combined, the substrate portion 13 is discarded, so that the Zener diode ZD of the reference voltage generating circuit 12 is insulated from the ground, and no current flows through the Zener diode ZD. No voltage is generated. Therefore, when the main substrate 1 and the sub-substrate 2 are subsequently combined, the reference voltage generation circuit 12 of the main substrate 1 does not operate, and only the reference voltage generation circuit 9 of the sub-substrate 2 generates the reference voltage. Therefore, as in the first embodiment, the individual adjustment of each substrate can be easily performed even in the middle of the manufacturing process, and when the circuit adjustment is performed by itself and when the main substrate 1 is combined. Since the magnitude of SW5V supplied to the sub-substrate 2 does not change, the process of adjusting the circuit can be simplified and the time can be shortened.
[0040]
Embodiment 4 FIG.
In the electric circuit device according to the fourth embodiment shown in FIG. 5, a mechanical switch 15 that can be turned on / off with respect to a Zener diode ZD is provided in the reference voltage generation circuit 14 of the main substrate 1 instead of the transistor of the second embodiment. They are connected in series. As described below, the same operation as that of the electric circuit device according to the first embodiment can be performed by turning on / off the switch 15.
[0041]
That is, when the sub-substrate 2 is individually adjusted, the external terminal 9a for the bias of the reference voltage generation circuit 9, the external terminal 9b for the output of the reference voltage, and the external terminal 8b for supplying the power supply voltage SW5V are shown in FIG. To the external power supply circuit 100 as described above. Thereby, the signal processing circuit 7 can be operated, and the circuit adjustment of the signal processing circuit 7 becomes possible even when the sub-board 2 is used alone.
[0042]
When the main substrate 1 is adjusted alone, the switch 15 is turned on, and the Zener diode ZD of the reference voltage generation circuit 14 is brought into conduction with the ground, whereby a reference voltage is generated in the Zener diode ZD.
[0043]
Further, when the main substrate 1 and the sub-substrate 2 are combined, the switch 15 is turned off so that the Zener diode ZD of the reference voltage generating circuit 14 is insulated from the ground. As a result, no current flows through the Zener diode ZD, and no reference voltage is generated. That is, when the main board 1 and the sub board 2 are combined, first, the switch 15 is turned off, the reference voltage generating circuit 14 of the main board 1 is not operated, and the circuit for generating the reference voltage is connected to the sub board 2. Only the reference voltage generation circuit 9 is used. Therefore, as in the first embodiment, the individual adjustment of each substrate can be easily performed even in the middle of the manufacturing process, and when the circuit adjustment is performed by itself and when the main substrate 1 is combined. Since the magnitude of SW5V supplied to the sub-substrate 2 does not change, the process of adjusting the circuit can be simplified and the time can be shortened.
[0044]
Embodiment 5 FIG.
In the electric circuit device of the fifth embodiment shown in FIG. 6, in the reference voltage generation circuit 16 of the main substrate 1, instead of the transistor of the second embodiment, a jumper wire 17 (for flexibility) is connected to the Zener diode ZD. Are connected in series. That is, the Zener diode ZD is grounded via the jumper line 17 when the main substrate 1 is manufactured. However, before cutting the jumper line 17, it is necessary to execute a single adjustment of the main board 1. In FIG. 6, the same reference numerals are given to the same portions as those in FIG. 3 described as the second embodiment.
[0045]
Next, the operation of the electric circuit device configured as described above will be described.
[0046]
First, when the sub-substrate 2 is individually adjusted, the external terminal 9a for the bias of the reference voltage generation circuit 9, the external terminal 9b for the output of the reference voltage, and the external terminal 8b for the supply of the power supply voltage SW5V are respectively shown in FIG. It is connected to the external power supply circuit 100 as shown. Thereby, the signal processing circuit 7 can be operated, and the circuit adjustment of the signal processing circuit 7 becomes possible even when the sub-board 2 is used alone.
[0047]
When the main substrate 1 is adjusted as a single unit, the zener diode ZD of the reference voltage generation circuit 16 is electrically connected to the ground by the jumper line 17 connecting the zener diode ZD of the reference voltage generation circuit 16 to the ground. Therefore, a reference voltage is generated in the Zener diode ZD.
[0048]
Further, when the main substrate 1 and the sub-substrate 2 are combined, the jumper line 17 is cut, whereby the Zener diode ZD of the reference voltage generation circuit 16 is insulated from the ground, and no current flows through the Zener diode ZD. No voltage is generated. Therefore, when the main substrate 1 and the sub-substrate 2 are subsequently combined, the reference voltage generation circuit 16 of the main substrate 1 does not operate, and only the reference voltage generation circuit 9 of the sub-substrate 2 generates a reference voltage. Therefore, as in the first embodiment, the individual adjustment of each substrate can be easily performed even in the middle of the manufacturing process, and when the circuit adjustment is performed by itself and when the main substrate 1 is combined. Since the magnitude of SW5V supplied to the sub-substrate 2 does not change, the process of adjusting the circuit can be simplified and the time can be shortened.
[0049]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0050]
According to the first aspect of the present invention, the sub-board has an external terminal connectable to an external power supply circuit different from the power supply circuit of the main board, and a reference voltage generation for a voltage supplied from the power supply circuit of the main board or the external power supply circuit. In the state where the sub-substrate is separated from the main substrate, a voltage is supplied to the sub-substrate from an external power supply circuit to perform simple adjustment, and the electric circuit is electrically connected to the main substrate and the sub-substrate. When the device is used, the reference voltage is supplied from the reference voltage generating means of the sub-substrate to the main substrate. Therefore, it is possible to provide an electric circuit device capable of simplifying the adjustment process in the manufacturing process and shortening the time. it can.
[0051]
According to the second aspect of the present invention, both of the reference voltage generating means of the main substrate and the sub-substrate can be constituted by Zener diodes, and can generate a predetermined reference voltage with high accuracy.
[0052]
According to the third aspect of the present invention, since the reference voltage generated by any one of the sub-substrates is set to be lower than any of the reference voltages of the other sub-substrates and the main substrate, In addition, a different reference voltage other than the reference voltage generated by one sub-substrate is not generated.
[0053]
According to the invention of claim 4, means for separating the reference voltage generating means from the power supply circuit is provided on the main board, and after forming the electric circuit device by combining the main board and the sub-board, any one of the The reference voltage is supplied from the sub-substrate to the main substrate, and the reference voltage generation means of the main substrate is not electrically operated.
[0054]
According to the fifth aspect of the present invention, the means for separating from the power supply circuit is constituted by a transistor which is turned off when the main substrate and the sub-substrate are combined, so that the circuit adjustment of the main substrate alone can be reliably performed.
[0055]
According to the invention of claim 6, as a means for separating from the power supply circuit, when the main board and the sub-board are combined, a part of the circuit board constituting the reference voltage generating means can be discarded. Can be easily connected to form an electric circuit device.
[0056]
According to the invention of claim 7, since the means for separating from the power supply circuit is constituted by a mechanical switch which can be turned off when the main board and the sub-board are combined, the circuit adjustment of the main board alone can be ensured. Can be implemented.
[0057]
According to the invention of claim 8, as means for separating from the power supply circuit, when the main board and the sub-board are combined, a part of the reference voltage generating means is constituted by a flexible insulated wire which can be cut. By connecting the substrates, an electric circuit device can be easily obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an electric circuit device according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an external power supply circuit connected to a sub-board.
FIG. 3 is a block diagram showing an electric circuit device according to a second embodiment of the present invention.
FIG. 4 is a block diagram showing an electric circuit device according to a third embodiment of the present invention.
FIG. 5 is a block diagram showing an electric circuit device according to a fourth embodiment of the present invention.
FIG. 6 is a block diagram showing an electric circuit device according to a fifth embodiment of the present invention.
FIG. 7 is a block diagram showing a conventional electric circuit device.
[Explanation of symbols]
Reference Signs List 1 main board, 2 sub board, 3 reference voltage generation circuit, 4 power supply circuit, 5 control circuit, 6 audio circuit, 7 signal processing circuit, 9, 10, 12, 14, 16 reference voltage generation circuit, 11 transistor, 13 discard Possible board parts, 15 switches, 17 jumpers, 100 external power circuits.

Claims (8)

It is driven by being connected to a main board having a power supply circuit and a means for generating a reference voltage for the voltage generated by the power supply circuit (hereinafter referred to as reference voltage generation means), and being connected to the power supply circuit of the main board. An electric circuit device including one or more sub-boards including a circuit,
The sub-board includes an external terminal connectable to an external power supply circuit different from the power supply circuit of the main board, and a reference voltage generation unit for a voltage supplied from the power supply circuit of the main board or the external power supply circuit,
In a state where the sub-board is separated from the main board, a single adjustment is performed by supplying a voltage from the external power supply circuit to the sub-board,
When the main substrate and the sub-substrate are electrically connected, a power supply voltage is supplied from the main substrate to the sub-substrate, and a reference voltage is supplied from the reference voltage generating means of the sub-substrate to the main substrate. An electric circuit device having a configuration as described above. 2. The electric circuit device according to claim 1, wherein each of the reference voltage generating means of the main substrate and the sub-substrate is a Zener diode. 3. The electric circuit device according to claim 2, wherein a reference voltage generated by any one of the sub-substrates is set to be lower than any of the reference voltages of the other sub-substrates and the main substrate. The main substrate is provided with a unit for separating the reference voltage generation unit from the power supply circuit, and after the electric circuit device is configured by combining the main substrate and the sub-substrate, the reference voltage is generated from one of the sub-substrates. 3. The electric circuit device according to claim 1, wherein the electric power is supplied to the main substrate, and the reference voltage generation unit of the main substrate is not electrically operated. 4. The electric circuit device according to claim 4, wherein the means for separating from the power supply circuit is a transistor that is turned off when the main substrate and the sub substrate are combined. 5. The device according to claim 4, wherein a part of the circuit board that constitutes the reference voltage generation means can be discarded when the main board and the sub board are combined as the means for separating from the power supply circuit. Electrical circuit equipment. The electric circuit device according to claim 4, wherein the means for separating from the power supply circuit is a mechanical switch that can be turned off when the main board and the sub board are combined. The means for separating from the power supply circuit is constituted by a flexible insulated wire capable of cutting a part of the reference voltage generating means when the main board and the sub-board are combined. 5. The electric circuit device according to 4.

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