CN201123041Y - Ringing off-hook detection signal generating device - Google Patents
Ringing off-hook detection signal generating device Download PDFInfo
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- CN201123041Y CN201123041Y CNU2007203051000U CN200720305100U CN201123041Y CN 201123041 Y CN201123041 Y CN 201123041Y CN U2007203051000 U CNU2007203051000 U CN U2007203051000U CN 200720305100 U CN200720305100 U CN 200720305100U CN 201123041 Y CN201123041 Y CN 201123041Y
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Abstract
The utility model relates to a ringing off-hook detecting signal generating device, which comprises a detecting unit, a first low-pass filtering unit, a second low-pass filtering unit and a comparing unit; the input terminal of the detecting unit is connected with a ringdown source, the output terminal is connected with the second low-pass filtering unit, and after the off-hook of the user, a voltage difference is generated at the both sides of the detecting unit; the first low-pass filtering unit is connected with the detecting unit, and connected with the first input terminal of the comparing unit, and the first low-pass filtering unit is connected with a reference power supply; the second low-pass filtering unit is connected with the detecting unit and the second input terminal of the comparing unit; the comparing unit is used to generate a ringing off-hook signal after the voltage difference is generated between the first input terminal and the second input terminal. The ringing off-hook detecting signal generating device has the advantages that the circuit is simple, the quantity of the elements is small, the threshold current is independent of the Vbat, the threshold is accurate, the linear variation caused by the Vbat of the detecting threshold current of the ringing off-hook detecting circuit and the large vibration problem are solved, and the reliability is high.
Description
Technical field
The utility model relates to communication technical field, particularly relates to a kind of ring off-hook detection signal generating apparatus.
Background technology
Along with developing rapidly of the communication technology, the ringing circuit function of one of seven basic functions that provide as common POTS (Plain Old TelephoneService, traditional older telephone systems) narrow-band user interface circuit is widely used.When the user has when call out inserting, POTS narrow-band user interface circuit need be given user's ringing-signal feeding, when the user under ringing condition during off-hook the user interface circuit needs can detect user's off-hook, and stop ring.
At present, the technical scheme of ring off-hook detection circuit of the prior art has two kinds of schemes, and scheme one is made up of as shown in Figure 1 module 10,11,12 and device R 4/R5/U1.Ringing signal flows through from R1, and R2/R3 gathers the voltage difference at R1 two ends, and R2/R3/C1 forms the low pass filter filters out alternating component.This circuit arrangement can be realized ring off-hook detection and caller off-hook detection simultaneously, and reference voltage Vref is this circuit reference data, and detection threshold is accurate.
Scheme two is made up of Rs, R1, R2, R3, R4, C1, C2 and comparator, as shown in Figure 2.Vbat (direct voltage)+Ring (alternating voltage is used to produce ring) is the ringing-current source; Ringing signal flows through from Rs resistance; The signal that the low pass filter that R1, R2, C1 form is gathered the Rs left side produces the input that the DAC signal is given comparator with the ground dividing potential drop; The signal that the low pass filter that R3, R4, C2 form is gathered the Rs right side produces another input that DB signal is given comparator with the ground dividing potential drop.Generally can select the resistance value of R1/R2/R3/R4 resistance value, and require R1/R2＞R3/R4 much larger than Rs.When user's ring and substation on-hook, phone is a high resistant, and the direct current that flows through Rs is close to zero, so the direct voltage of the Rs resistance left and right sides is equal substantially, and the direct voltage of DAC is higher than the direct voltage of DB at this moment; When the substation off-hook, loop is a low-resistance, and the voltage on Rs right side is raised, therefore accordingly the voltage of DB network is raised, when DB voltage is higher than DAC voltage, the comparator upset, this moment, comparator generated corresponding ring off-hook detection signal, and the notice ringing set stops ring.
The detection threshold electric current of this circuit is:
Above-mentioned detection threshold electric current is the critical value of comparator when being about to overturn, and that is to say when DAC is identical with DB voltage, and the current value by Rs is detection threshold electric current I s.
In realizing the utility model process, utility model people finds that there are the following problems at least in the prior art: though the detection threshold of prior art scheme one ring off-hook detection circuit is accurate, it realizes the circuit complexity, and used device is more; Though prior art scheme two ring off-hook detection circuit is simple in structure, device is less, and the detection threshold electric current is with the direct voltage Vbat linear change in ringing-current source, and fluctuation is big, is easy to cause erroneous judgement.
Summary of the invention
Problem to be solved in the utility model provides a kind of ring off-hook detection circuit arrangement, solves circuit complexity in the ring off-hook detection circuit, and the more and detection threshold electric current of device is with ringing-current source linear change, and big problem fluctuates.
For achieving the above object, the technical solution of the utility model provides a kind of ring off-hook detection signal generating apparatus, comprises detecting unit, first low-pass filter unit, second low-pass filter unit and comparing unit; The input of described detecting unit connects the ringing-current source, and output connects described second low-pass filter unit, and described detecting unit both sides produce voltage difference behind user's off-hook; Described first low-pass filter unit and described detecting unit, and the first input end of described comparing unit is continuous, is used for low-pass filtering is carried out in described ringing-current source, described first low-pass filter unit also is connected with reference power source; Described second low-pass filter unit and described detecting unit, and second input of described comparing unit is continuous, is used for low-pass filtering is carried out in described ringing-current source; Described comparing unit is used for generating a ring off hook signal after described first input end and described second input generation voltage difference.
The technical solution of the utility model also provides a kind of ring off-hook detection signal generating apparatus, comprises detecting unit, first low-pass filter unit, second low-pass filter unit and comparing unit; The input of described detecting unit connects the ringing-current source, and output connects described second low-pass filter unit, is used for behind user's off-hook in described detecting unit both sides generation voltage difference; Described first low-pass filter unit and described detecting unit, and the first input end of described comparing unit is continuous, is used for low-pass filtering is carried out in described ringing-current source; Described second low-pass filter unit and described detecting unit, and second input of described comparing unit is continuous, is used for low-pass filtering is carried out in described ringing-current source, described second low-pass filter unit also is connected with reference power source; Described comparing unit is used for generating a ring off hook signal after described first input end and described second input generation voltage difference.
An embodiment in the technique scheme has following advantage: utility model the utility model is connected to reference power source by first low-pass filter unit, the threshold current that flows through detecting unit is determined by described reference power source, realized that detection threshold electric current and Vbat are irrelevant, thresholding is accurate, the reliability height, and circuit is simple, and device is less.
Description of drawings
Fig. 1 is the circuit diagram of a kind of ring off-hook detection signal generating apparatus in the prior art scheme;
Fig. 2 is the circuit diagram of the another kind of ring off-hook detection signal generating apparatus in the prior art scheme;
Fig. 3 is the circuit diagram of the ring off-hook detection signal generating apparatus of the utility model one.
Fig. 4 is the circuit diagram of the ring off-hook detection signal generating apparatus of the utility model two.
Embodiment
Below in conjunction with drawings and Examples, embodiment of the present utility model is described in further detail:
The circuit diagram of the generating apparatus of the ring off-hook detection signal of the utility model one comprises detecting unit 31, first low-pass filter unit 32, second low-pass filter unit 33 and comparing unit 34 as shown in Figure 3; The input of detecting unit 31 connects the ringing-current source, and output connects second low-pass filter unit 33; First low-pass filter unit 32 is connected with input, reference power source and the first input end of comparing unit 34 of detecting unit 31 respectively; Second input of comparing unit 34 connects second low-pass filter unit 33, output output ring off-hook detection signal.Detecting unit 31 passes through direct current behind user's off-hook, thereby produces voltage difference in the both sides of detecting unit 31, and the voltage difference that first low-pass filter unit 32 and second low-pass filter unit 33 produce detecting unit 31 both sides is respectively introduced comparing unit 34.Like this will be because detecting unit 31 both sides produce voltage difference behind user's off-hook, and can this voltage difference be introduced comparing unit 34 by first low-pass filter unit 32 and second low-pass filter unit 33, therefore comparing unit 34 can overturn behind off-hook, generates a ring off hook signal.Wherein first low-pass filter unit 32 and second low-pass filter unit 33 also are used for low-pass filtering is carried out in described ringing-current source, remove the influence of described ringing-current source medium-high frequency voltage to described comparing unit.Detecting unit 31 comprises a sampling resistor Rs, and the input of sampling resistor Rs connects the input of ringing-current source Vbat+Ring (voltage) and resistance R 1, and the output of sampling resistor Rs connects the input of resistance R 3.
First low-pass filter unit 32 comprises first resistance, second resistance and first electric capacity, the input of the input joint detection unit 31 of described first resistance, output connect the input of the input of described second resistance, described first electric capacity and the first input end of comparing unit 34; The output of described second resistance connects reference power source; The output head grounding of described first electric capacity, first electric capacity and second resistance constitute low pass filter low-pass filtering are carried out in described ringing-current source, remove the influence of described ringing-current source medium-high frequency voltage to described comparing unit.Wherein, described first resistance and described second resistance can be made up of single resistance, also can be combined by connection in series-parallel by a plurality of resistance, and first resistance is that resistance R 1, the second resistance is resistance R 2 in the present embodiment; Described first electric capacity can be made up of single electric capacity, also can be combined by connection in series-parallel by a plurality of electric capacity, and first electric capacity is capacitor C 1 in the present embodiment.First low-pass filter unit 32 can be multi-way shared, and device is few, and circuit is simple, the reliability height.
The input of resistance R 1 connects the input of ringing-current source Vbat+Ring and sampling resistor Rs, and the output of resistance R 1 connects the output of resistance R 2 and capacitor C 1; The input of resistance R 2 connects reference power source Vcc, and the output of resistance R 2 connects the output of resistance R 1 and capacitor C 1; The input end grounding of capacitor C 1, the output of capacitor C 1 connects the output of resistance R 1 and resistance R 2.
Second low-pass filter unit 33 comprises the 3rd resistance, the 4th resistance and second electric capacity; The output of the input joint detection unit 31 of described the 3rd resistance, output connect the input of the input of described the 4th resistance, described second electric capacity and second input of comparing unit 34; The output head grounding of described the 4th resistance; The output head grounding of described second electric capacity, second electric capacity and the 4th resistance constitute low pass filter low-pass filtering are carried out in described ringing-current source, remove the influence of described ringing-current source medium-high frequency voltage to described comparing unit.Wherein, described the 3rd resistance and described the 4th resistance can be made up of single resistance, also can be combined by connection in series-parallel by a plurality of resistance, and the 3rd resistance is that resistance R 3, the four resistance are resistance R 4 in the present embodiment; Described second electric capacity can be made up of single electric capacity, also can be combined by connection in series-parallel by a plurality of electric capacity, and second electric capacity is capacitor C 2 in the present embodiment.
The input of resistance R 3 connects the output of sampling resistor Rs, and the output of resistance R 3 connects the output of resistance R 4 and capacitor C 2; The input end grounding of resistance R 4, the output of resistance R 4 connects the output of resistance R 3 and capacitor C 2; The input end grounding of capacitor C 2, the output of capacitor C 2 connects the output of resistance R 3 and resistance R 4.
Comparing unit 34 comprises first input end, second input and output, and comparing unit 34 first input ends connect the output of resistance R 1, resistance R 2 and capacitor C 1; Comparing unit 34 second inputs connect the output of resistance R 3, resistance R 4 and capacitor C 2; Comparing unit 34 outputs output ring off-hook detection signal.
During ring, the ringing signal sampling resistor Rs that flows through, the ringing signal that sampling resistor Rs is used for flowing through is converted into voltage signal.Ringing signal that first low-pass filter unit of being made up of resistance R 1, resistance R 2 and capacitor C 1 32 is gathered sampling resistor Rs inputs and the magnitude of voltage of the d. c. voltage signal value of reference power source VCC dividing potential drop generation as the first input end of comparing unit 34; The d. c. voltage signal value that the voltage signal that second low-pass filter unit of being made up of resistance R 3, resistance R 4 and capacitor C 2 33 is gathered sampling resistor Rs outputs and ground dividing potential drop produce is as the magnitude of voltage of the first input end of comparing unit 34.If get R1=R3, R2=R4, then the detection of Fig. 3 circuit is flow through the threshold current of sampling resistor Rs and is:
The value of threshold current Is and Vbat are irrelevant as can be seen from the above equation, and be only relevant with preset parameters such as Vcc, R3, Rs and R4, so this threshold current value can keep stable, can not occur fluctuating.
Present embodiment is connected to reference power source by first low-pass filter unit 32, the threshold current that flows through detecting unit 31 is determined by described reference power source, by R1=R3 is set, R2=R4 has realized that detection threshold electric current and Vbat have nothing to do, and thresholding is accurate, the reliability height, and circuit is simple, device is less, has solved detection threshold electric current in the ring off-hook detection circuit with the Vbat linear change, and big problem fluctuates.
Reference power source in the foregoing description is a positive supply, and the utility model also can be realized by negative reference power source certainly, specifically as shown in Figure 4, comprises detecting unit 31, first low-pass filter unit 32, second low-pass filter unit 33 and comparing unit 34; The input of detecting unit 31 connects the ringing-current source, and output connects second low-pass filter unit 33; Second low-pass filter unit 33 is connected with output, reference power source and the first input end of comparing unit 34 of detecting unit 31 respectively; Second input of comparing unit 34 connects second low-pass filter unit 33, output output ring off-hook detection signal.Detecting unit 31 passes through direct current behind user's off-hook, thereby produces voltage difference in the both sides of detecting unit 31, and the voltage difference that first low-pass filter unit 32 and second low-pass filter unit 33 produce detecting unit 31 both sides is respectively introduced comparing unit 34.Like this will be because detecting unit 31 both sides produce voltage difference behind user's off-hook, and can this voltage difference be introduced comparing unit 34 by first low-pass filter unit 32 and second low-pass filter unit 33, therefore comparing unit 34 can overturn behind off-hook, generates a ring off hook signal.Wherein first low-pass filter unit 32 and second low-pass filter unit 33 also are used for low-pass filtering is carried out in described ringing-current source, remove the influence of described ringing-current source medium-high frequency voltage to described comparing unit.
Detecting unit 31 comprises a sampling resistor Rs, and the input of sampling resistor Rs connects the input of ringing-current source Vbat+Ring (voltage) and resistance R 1, and the output of sampling resistor Rs connects the input of resistance R 3.
First low-pass filter unit 32 comprises first resistance, second resistance and first electric capacity, the input of the input joint detection unit 31 of described first resistance, output connect the input of the input of described second resistance, described first electric capacity and the first input end of comparing unit 34; The output head grounding of described second resistance; The output head grounding of described first electric capacity, first electric capacity and second resistance constitute low pass filter low-pass filtering are carried out in described ringing-current source, remove the influence of described ringing-current source medium-high frequency voltage to described comparing unit.Wherein, described first resistance and described second resistance can be made up of single resistance, also can be combined by connection in series-parallel by a plurality of resistance, and first resistance is that resistance R 1, the second resistance is resistance R 2 in the present embodiment; Described first electric capacity can be made up of single electric capacity, also can be combined by connection in series-parallel by a plurality of electric capacity, and first electric capacity is capacitor C 1 in the present embodiment.First low-pass filter unit 32 can be multi-way shared, and device is few, and circuit is simple, the reliability height.
The input of resistance R 1 connects the input of ringing-current source Vbat+Ring and sampling resistor Rs, and the output of resistance R 1 connects the output of resistance R 2 and capacitor C 1; The input end grounding of resistance R 2, the output of resistance R 2 connects the output of resistance R 1 and capacitor C 1; The input end grounding of capacitor C 1, the output of capacitor C 1 connects the output of resistance R 1 and resistance R 2.
Second low-pass filter unit 33 comprises the 3rd resistance, the 4th resistance and second electric capacity; The output of the input joint detection unit 31 of described the 3rd resistance, output connect the input of the input of described the 4th resistance, described second electric capacity and second input of comparing unit 34; The output termination reference power source-Vcc of described the 4th resistance; The output head grounding of described second electric capacity, second electric capacity and the 4th resistance constitute low pass filter low-pass filtering are carried out in described ringing-current source, remove the influence of described ringing-current source medium-high frequency voltage to described comparing unit.Wherein, described the 3rd resistance and described the 4th resistance can be made up of single resistance, also can be combined by connection in series-parallel by a plurality of resistance, and the 3rd resistance is that resistance R 3, the four resistance are resistance R 4 in the present embodiment; Described second electric capacity can be made up of single electric capacity, also can be combined by connection in series-parallel by a plurality of electric capacity, and second electric capacity is capacitor C 2 in the present embodiment.
The input of resistance R 3 connects the output of sampling resistor Rs, and the output of resistance R 3 connects the output of resistance R 4 and capacitor C 2; Input termination-the Vcc of resistance R 4, the output of resistance R 4 connects the output of resistance R 3 and capacitor C 2; The input end grounding of capacitor C 2, the output of capacitor C 2 connects the output of resistance R 3 and resistance R 4.
Comparing unit 34 comprises first input end, second input and output, and comparing unit 34 first input ends connect the output of resistance R 1, resistance R 2 and capacitor C 1; Comparing unit 34 second inputs connect the output of resistance R 3, resistance R 4 and capacitor C 2; Comparing unit 34 outputs output ring off-hook detection signal.
During ring, the ringing signal sampling resistor Rs that flows through, the ringing signal that sampling resistor Rs is used for flowing through is converted into voltage signal.Ringing signal that second low-pass filter unit of being made up of resistance R 3, resistance R 4 and capacitor C 2 33 is gathered sampling resistor Rs outputs and the magnitude of voltage of the d. c. voltage signal value of reference power source-VCC dividing potential drop generation as second input of comparing unit 34; The d. c. voltage signal value that the voltage signal that first low-pass filter unit of being made up of resistance R 1, resistance R 2 and capacitor C 1 32 is gathered sampling resistor Rs inputs and ground dividing potential drop produce is as the magnitude of voltage of the first input end of comparing unit 34.If get R1=R3, R2=R4, then the detection of Fig. 4 circuit is flow through the threshold current of sampling resistor Rs and is:
As can be seen from the above equation, the value of threshold current Is and Vbat are irrelevant among this embodiment, and be only relevant with preset parameters such as Vcc, R3, Rs and R4, so this threshold current value can keep stable, can not occur fluctuating.
Present embodiment is connected to reference power source by second low-pass filter unit 33, the threshold current that flows through detecting unit 31 is determined by described reference power source, realized that detection threshold electric current and Vbat are irrelevant, thresholding is accurate, the reliability height, and circuit is simple, and device is less, solved detection threshold electric current in the ring off-hook detection circuit with the Vbat linear change, big problem fluctuates.
The above only is an execution mode of the present utility model; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the utility model principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection range of the present utility model.
Claims (8)
1, a kind of ring off-hook detection signal generating apparatus is characterized in that, comprises detecting unit, first low-pass filter unit, second low-pass filter unit and comparing unit;
The input of described detecting unit connects the ringing-current source, and output connects described second low-pass filter unit, and described detecting unit both sides produce voltage difference behind user's off-hook;
Described first low-pass filter unit and described detecting unit, and the first input end of described comparing unit is continuous, is used for low-pass filtering is carried out in described ringing-current source, described first low-pass filter unit also is connected with reference power source;
Described second low-pass filter unit and described detecting unit, and second input of described comparing unit is continuous, is used for low-pass filtering is carried out in described ringing-current source;
Described comparing unit is used for generating a ring off hook signal after described first input end and described second input generation voltage difference.
2, the signal generating apparatus of ring off-hook detection according to claim 1 is characterized in that, described first low-pass filter unit comprises first resistance, second resistance and first electric capacity;
The input of described first resistance is connected with described detecting unit, and output connects the first input end of described second resistance, described first electric capacity and described comparing unit;
The output of described second resistance connects reference power source;
The output head grounding of described first electric capacity, described first electric capacity and described second resistance constitute low pass filter low-pass filtering are carried out in described ringing-current source.
3, the signal generating apparatus of ring off-hook detection according to claim 1 is characterized in that, described second low-pass filter unit comprises the 3rd resistance, the 4th resistance and second electric capacity;
The input of described the 3rd resistance connects described detecting unit, and output connects second input of described the 4th resistance, described second electric capacity and described comparing unit;
The output head grounding of described the 4th resistance;
The output head grounding of described second electric capacity, described second electric capacity and described the 4th resistance constitute low pass filter low-pass filtering are carried out in described ringing-current source.
4, as ring off-hook detection signal generating apparatus as described in the claim 3, it is characterized in that described first resistance equates that with the resistance value of described the 3rd resistance described second resistance equates with the resistance value of described the 4th resistance.
5, a kind of ring off-hook detection signal generating apparatus is characterized in that, comprises detecting unit, first low-pass filter unit, second low-pass filter unit and comparing unit;
The input of described detecting unit connects the ringing-current source, and output connects described second low-pass filter unit, is used for behind user's off-hook in described detecting unit both sides generation voltage difference;
Described first low-pass filter unit and described detecting unit, and the first input end of described comparing unit is continuous, is used for low-pass filtering is carried out in described ringing-current source;
Described second low-pass filter unit and described detecting unit, and second input of described comparing unit is continuous, is used for low-pass filtering is carried out in described ringing-current source, described second low-pass filter unit also is connected with reference power source;
Described comparing unit is used for generating a ring off hook signal after described first input end and described second input generation voltage difference.
6, as ring off-hook detection signal generating apparatus as described in the claim 5, it is characterized in that described first low-pass filter unit comprises first resistance, second resistance and first electric capacity;
The input of described first resistance connects described detecting unit, and output connects the first input end of described second resistance, described first electric capacity and described comparing unit;
The output head grounding of described second resistance;
The output head grounding of described first electric capacity, described first electric capacity and described second resistance constitute low pass filter low-pass filtering are carried out in described ringing-current source.
7, as ring off-hook detection signal generating apparatus as described in the claim 5, it is characterized in that described second low-pass filter unit comprises the 3rd resistance, the 4th resistance and second electric capacity;
The input of described the 3rd resistance connects described detecting unit, and output connects second input of described the 4th resistance, described second electric capacity and described comparing unit;
The output of described the 4th resistance connects described reference power source;
The output head grounding of described second electric capacity, described second electric capacity and described the 4th resistance constitute low pass filter low-pass filtering are carried out in described ringing-current source.
8, as ring off-hook detection signal generating apparatus as described in the claim 7, it is characterized in that described first resistance equates that with the resistance value of described the 3rd resistance described second resistance equates with the resistance value of described the 4th resistance.
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| Application Number | Priority Date | Filing Date | Title |
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| CNU2007203051000U CN201123041Y (en) | 2007-12-07 | 2007-12-07 | Ringing off-hook detection signal generating device |
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| Application Number | Priority Date | Filing Date | Title |
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| CNU2007203051000U CN201123041Y (en) | 2007-12-07 | 2007-12-07 | Ringing off-hook detection signal generating device |
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| CN201123041Y true CN201123041Y (en) | 2008-09-24 |
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| CNU2007203051000U Expired - Lifetime CN201123041Y (en) | 2007-12-07 | 2007-12-07 | Ringing off-hook detection signal generating device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111405131A (en) * | 2020-03-30 | 2020-07-10 | 深圳震有科技股份有限公司 | Method, system and storage medium for detecting far-end off-hook signal |
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2007
- 2007-12-07 CN CNU2007203051000U patent/CN201123041Y/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111405131A (en) * | 2020-03-30 | 2020-07-10 | 深圳震有科技股份有限公司 | Method, system and storage medium for detecting far-end off-hook signal |
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