Open-phase detection circuit of three-phase power supply and welding equipment
By using a voltage divider circuit and an optocoupler detection circuit in a three-phase power supply, a simple and low-cost detection of phase loss in a three-phase power supply is achieved. This solves the problems of welding machine output power and welding performance when a three-phase power supply is connected to a single-phase power grid or when a phase is missing, and improves the reliability and safety of the detection.
Patent Information
- Application Number
- CN202520271539.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2025-12-05
- Estimated Expiration
- 2035-02-20
AI Technical Summary
In existing technologies, when a three-phase power supply is connected to a single-phase power grid or a power supply with a missing phase, it affects the output power and welding performance of the welding machine, and there is a lack of effective means of detecting missing phases.
By employing a first voltage divider circuit and an optocoupler, the phase lines of the three-phase power supply are divided and optocoupled to detect the positive half-cycle waveform of the phase lines. The electrical signal at the phase loss detection output terminal is adjusted using a photosensitive element and a pull-up resistor to achieve phase loss detection of the three-phase power supply.
The circuit structure for phase loss detection has been simplified, reducing costs and improving the reliability and safety of detection, enabling accurate determination of phase loss in a three-phase power supply.
Smart Images
Figure CN223637615U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of phase loss detection, especially to a three-phase power supply phase loss detection circuit and welding equipment. BACKGROUND
[0002] For inverter welding machines or other high-power switching power supplies, the input power is usually an industrial AC power supply, which includes three-phase power supply and single-phase power supply. If the inverter welding machine with three-phase power input is connected to a single-phase power grid or a three-phase power supply with phase loss, the output power of the welding machine will be affected, and thus the welding performance and welding effect of the welding machine will be affected. Therefore, how to detect the phase loss of the input power has become a technical problem that needs to be solved urgently. SUMMARY
[0003] The utility model provides a three-phase power supply phase loss detection circuit and welding equipment, simplify the overall structure of phase loss detection circuit, reduce the cost.
[0004] In a first aspect, the utility model provides a three-phase power supply phase loss detection circuit, comprising:
[0005] A first voltage dividing circuit includes a first diode, a second diode, a first resistor, and a second resistor. The first voltage dividing circuit further includes a first input terminal, a second input terminal, a third input terminal, a first output terminal, and a second output terminal. The first input terminal is electrically connected to a first phase line of the three-phase power supply, the second input terminal is electrically connected to a second phase line of the three-phase power supply, and the third input terminal is electrically connected to a third phase line of the three-phase power supply. The anode of the first diode is electrically connected to the first input terminal, and the anode of the second diode is electrically connected to the second input terminal. The cathode of the first diode and the cathode of the second diode are both electrically connected to the first output terminal. The first end of the second resistor is electrically connected to the third input terminal, and the second end of the second resistor is electrically connected to the second output terminal.
[0006] An optoelectronic coupler includes a photosensitive element, a light-emitting diode, and a pull-up resistor. The anode of the light-emitting diode is electrically connected to the first output terminal, and the cathode of the light-emitting diode is electrically connected to the second output terminal. The first end of the pull-up resistor is electrically connected to a power supply, the second end of the pull-up resistor is electrically connected to the first end of the photosensitive element, and the second end of the photosensitive element is electrically connected to a ground terminal. The first end of the photosensitive element is electrically connected to a phase loss detection output terminal.
[0007] Optionally, the first voltage dividing circuit further includes a filter circuit.
[0008] One end of the filter circuit is electrically connected to the first output terminal, and the other end of the filter circuit is electrically connected to the second output terminal.
[0009] Optionally, the first voltage dividing circuit further comprises a voltage protection circuit.
[0010] One end of the voltage protection circuit is electrically connected with the first output end, and the other end of the voltage protection circuit is electrically connected with the second output end.
[0011] Optionally, the filter circuit comprises a first capacitor.
[0012] Optionally, the voltage protection circuit comprises a transient voltage suppression diode.
[0013] An anode of the transient voltage suppression diode is electrically connected with the second output end, and a cathode of the transient voltage suppression diode is electrically connected with the first output end.
[0014] Optionally, the open-phase detection circuit further comprises a second voltage dividing circuit.
[0015] The second voltage dividing circuit is electrically connected between the first end of the photosensitive element and the open-phase detection output end.
[0016] Optionally, the second voltage dividing circuit comprises a fourth resistor and a fifth resistor.
[0017] A first end of the fourth resistor is electrically connected with the first end of the photosensitive element, a second end of the fourth resistor is respectively electrically connected with a first end of the fifth resistor and the open-phase detection output end, and a second end of the fifth resistor is electrically connected with the ground end.
[0018] In a second aspect, the utility model also provides a kind of welding equipment, including the open-phase detection circuit of three-phase power supply of first aspect.
[0019] The technical scheme of the utility model, by setting first voltage dividing circuit and a photoelectric coupler, in a voltage dividing circuit, first diode is electrically connected with first input end, and second diode is electrically connected with second input end, to realize the positive half-cycle waveform detection of first input end and second input end, and export corresponding output electric signal to first output end, the electric signal of first output end can control photoelectric coupler to turn on or disconnect, and then adjust the electric signal of open-phase detection output end, according to the electric signal pulse proportion of open-phase detection output end, to determine the open-phase of three-phase power supply.Such, only one photoelectric coupler is arranged in the utility model, and the open-phase detection of three-phase power supply can be realized, few components are used, circuit structure is simple, and cost is low. BRIEF DESCRIPTION OF DRAWINGS
[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description, obviously, the drawings described in the following description are some specific embodiments of the present application, for those skilled in the art, according to the basic concepts of device structure, driving method and manufacturing method disclosed and prompted by various embodiments of the present application, other structures and drawings can be expanded and extended, needless to say, these should be within the scope of the claims of the present application.
[0021] Figure 1 The circuit structure schematic diagram of the phase loss detection circuit of the three-phase power supply provided by the embodiment of the present application is shown in the figure.
[0022] Figure 2 The output waveform diagram of the phase loss detection circuit of the three-phase power supply provided by the embodiment of the present application is shown in the figure.
[0023] Figure 3 The output waveform diagram of another phase loss detection circuit of the three-phase power supply provided by the embodiment of the present application is shown in the figure.
[0024] Figure 4 The output waveform diagram of another phase loss detection circuit of the three-phase power supply provided by the embodiment of the present application is shown in the figure.
[0025] Figure 5 The circuit structure schematic diagram of another phase loss detection circuit of the three-phase power supply provided by the embodiment of the present application is shown in the figure.
[0026] Figure 6 The circuit structure schematic diagram of another phase loss detection circuit of the three-phase power supply provided by the embodiment of the present application is shown in the figure.
[0027] Figure 7 The circuit structure schematic diagram of another phase loss detection circuit of the three-phase power supply provided by the embodiment of the present application is shown in the figure. Specific implementation
[0028] In order to make the purpose, technical scheme and advantages of the present application more clear, the following will refer to the drawings in the embodiment of the present application, and the technical scheme of the present application will be described clearly and completely through the implementation, obviously, the described embodiment is a part of the embodiment of the present application, not all the embodiments. Based on the basic concepts disclosed and prompted by the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.
[0029] Figure 1 The circuit structure schematic diagram of the phase loss detection circuit of the three-phase power supply provided by the embodiment of the present application is shown in the figure. Figure 1As shown, the phase-loss detection circuit of the three-phase power supply comprises a first voltage dividing circuit 10 and a photoelectric coupler 20. The first voltage dividing circuit 10 comprises a first diode D1, a second diode D2, a first resistor R1 and a second resistor R2; the first voltage dividing circuit 10 further comprises a first input end IN1, a second input end IN2, a third input end IN3, a first output end O1 and a second output end O2; the first input end IN1 is electrically connected with a first phase line of the three-phase power supply, the second input end IN2 is electrically connected with a second phase line of the three-phase power supply, and the third input end IN3 is electrically connected with a third phase line of the three-phase power supply; the anode of the first diode D1 is electrically connected with the first input end IN1, and the anode of the second diode D2 is electrically connected with the second input end IN2; the cathode of the first diode D1 and the cathode of the second diode D2 are both electrically connected with a first end of the first resistor R1, and a second end of the first resistor R1 is electrically connected with the first output end O1; a first end of the second resistor R2 is electrically connected with the third input end IN3, and a second end of the second resistor R2 is electrically connected with the second output end O2. The photoelectric coupler 20 comprises a photosensitive element 21, a light-emitting diode 22 and a pull-up resistor R0; the anode of the light-emitting diode 22 is electrically connected with the first output end O1, and the cathode of the light-emitting diode 22 is electrically connected with the second output end O2; a first end of the pull-up resistor R0 is electrically connected with a power supply VCC, a second end of the pull-up resistor R0 is electrically connected with a first end of the photosensitive element 21, and a second end of the photosensitive element 21 is electrically connected with a ground end GND; the first end of the photosensitive element 21 is electrically connected with a phase-loss detection output end PL.
[0030] The power supply voltage of the power supply VCC can be set according to actual needs, and the power supply voltage of the power supply VCC is selected from the range of 10V-20V, and in an example embodiment, the power supply voltage of the power supply VCC is 15V.
[0031] Specifically, when the three-phase power supply is not phase-loss, the voltage amplitude of the first input end IN1 and the second input end IN2 is greater than the voltage amplitude of the third input end IN3, the light-emitting diode 22 emits light, the photosensitive element 21 is turned on, and the phase-loss detection output end PL outputs a low level; when the voltage amplitude of the first input end IN1 or the second input end IN2 is less than the voltage amplitude of the third input end IN3, the light-emitting diode 22 does not emit light, the photosensitive element 21 is not turned on, and the phase-loss detection output end PL outputs a high level.
[0032] Figure 2 The output waveform diagram of the phase-loss detection circuit of the three-phase power supply provided by the utility model embodiment is as shown in Figure 2As shown, the red dashed line represents the voltage waveform of the electrical signal of the first phase line provided to the first input terminal IN1, transmitted through the first diode D1 and the first resistor R1, and transmitted to the first output terminal (point O1); the green dashed line represents the voltage waveform of the electrical signal of the second phase line provided to the second input terminal IN2, transmitted through the second diode D2 and the first resistor R1, and transmitted to the first output terminal (point O1); the red solid line represents the voltage waveform of the first output terminal (point O1); and the black solid line represents the voltage waveform of the phase loss detection output terminal PL. Since the diode has a unidirectional conduction characteristic, only the positive half cycle waveform is retained after the electrical signal of the first phase line is transmitted to the first output terminal (point O1) through the first diode D1 and the like, and only the positive half cycle waveform is retained after the electrical signal of the second phase line is transmitted to the first output terminal (point O1) through the second diode D2 and the resistor and the like. When the waveforms transmitted to the first output terminal (point O1) by the first phase line and the second phase line are both positive half cycle waveforms, the first output terminal (point O1) selects the waveform with the larger voltage of the two positive half cycles as the output of the point, so that the waveform of the first output terminal (point O1) includes two wave peaks in one period. When the voltage of the first output terminal (point O1) is greater than zero, the light-emitting diode 22 is turned on and emits light, and the photosensitive element 21 is turned on, so that the photosensitive element 21 transmits the electrical signal of the ground terminal GND to the phase loss detection output terminal PL. At this time, the phase loss detection output terminal PL outputs a low level. When the voltage signals transmitted to the first output terminal (point O1) by the first phase line and the second phase line are low levels, the light-emitting diode 22 is not turned on and does not emit light, and the photosensitive element 21 is not turned on, so that the pull-up resistor R0 pulls the potential of the phase loss detection output terminal PL to be equal to the potential of the power supply VCC, and outputs a high level. In summary, when the three-phase power supply is not phase loss, the electrical signal waveform output by the phase loss detection output terminal PL is a square wave, and the high level of the square wave accounts for 1 / 3 in one period T.
[0033] Correspondingly, when the three-phase power supply is phase loss, and the first phase line is phase loss or the second phase line is phase loss, when the voltage amplitude of the first input terminal IN1 or the second input terminal IN2 is greater than the voltage amplitude of the third input terminal IN3, the light-emitting diode 22 emits light, the photosensitive element 21 is turned on, and the phase loss detection output terminal PL outputs a low level; when the voltage amplitude of the first input terminal IN1 or the second input terminal IN2 is less than the voltage amplitude of the third input terminal IN3, the light-emitting diode 22 does not emit light, the photosensitive element 21 is not turned on, and the phase loss detection output terminal PL outputs a high level.
[0034] Figure 3 The output waveform diagram of another three-phase power supply phase loss detection circuit provided by the embodiment of the utility model is shown in FIG. 4. Figure 3As shown, the red solid line represents the voltage waveform of the electrical signal provided to the first input terminal IN1 or the second input terminal IN2, transmitted to the first output terminal (O1 point) through the first diode D1 and the first resistor R1, and the black solid line represents the voltage waveform of the phase loss detection output terminal PL. Since the diode has a unidirectional conduction characteristic, only the positive half cycle waveform is retained after the electrical signal of the first input terminal IN1 or the second input terminal IN2 is transmitted to the first output terminal (O1 point) through the first diode D1 or the second diode D2, etc. Since the first phase line or the second phase line is phase loss, the waveform of the first output terminal (O point) only includes the voltage waveform of the positive half cycle in one period. When the voltage of the first output terminal (O1 point) is greater than zero, the light-emitting diode 22 is turned on and emits light, and the photosensitive element 21 is turned on. The photosensitive element 21 will transmit the electrical signal of the ground terminal GND to the phase loss detection output terminal PL, at which time the phase loss detection output terminal PL outputs a low level. When the voltage signal of the first phase line and the second phase line transmitted to the first output terminal (O1 point) is a low level, the light-emitting diode 22 is not turned on and emits light, and the photosensitive element 21 is not turned on. The pull-up resistor R0 pulls the potential of the phase loss detection output terminal PL to be equal to the potential of the power supply VCC, and outputs a high level. In summary, when the three-phase power supply is phase loss, and the first phase line or the second phase line is phase loss, the electrical signal waveform output by the phase loss detection output terminal PL is a square wave, and the proportion of the high level of the square wave in one period T is 1 / 2.
[0035] Correspondingly, Figure 4 The output waveform diagram of another three-phase power supply phase loss detection circuit provided by the embodiment of the utility model is shown as Figure 4 As shown, the red solid line represents the voltage waveform of the electrical signal provided to the first input terminal IN1 or the second input terminal IN2, transmitted to the first output terminal (O1 point) through the first diode D1 and the first resistor R1, and the black solid line represents the voltage waveform of the phase loss detection output terminal PL. Since the diode has a unidirectional conduction characteristic, only the positive half cycle waveform is retained after the electrical signal of the first input terminal IN1 or the second input terminal IN2 is transmitted to the first output terminal (O1 point) through the first diode D1 or the second diode D2, etc. Since the first phase line or the second phase line is phase loss, the waveform of the first output terminal (O point) only includes the voltage waveform of the positive half cycle in one period. When the voltage of the first output terminal (O1 point) is greater than zero, the light-emitting diode 22 is turned on and emits light, and the photosensitive element 21 is turned on. The photosensitive element 21 will transmit the electrical signal of the ground terminal GND to the phase loss detection output terminal PL, at which time the phase loss detection output terminal PL outputs a low level. When the voltage signal of the first phase line and the second phase line transmitted to the first output terminal (O1 point) is a low level, the light-emitting diode 22 is not turned on and emits light, and the photosensitive element 21 is not turned on. The pull-up resistor R0 pulls the potential of the phase loss detection output terminal PL to be equal to the potential of the power supply VCC, and outputs a high level. In summary, when the three-phase power supply is phase loss, and the first phase line or the second phase line is phase loss, the electrical signal waveform output by the phase loss detection output terminal PL is a square wave, and the proportion of the high level of the square wave in one period T is 1 / 2.
[0036] Specifically, the intermediate value 5 / 12 between 1 / 3 and 1 / 2 is taken as a demarcation point. When the proportion of the high level of the voltage waveform of the phase loss detection output terminal PL in one period T is less than 5 / 12, it is indicated that the detected three-phase power supply is not phase loss. If the proportion of the high level in one period T is greater than or equal to 5 / 12, it is indicated that the detected three-phase power supply has a phase loss problem.
[0037] The technical scheme provided by the utility model discloses, through setting up first voltage dividing circuit and one photoelectric coupler, setting up the first diode of electric connection with the first input end and the second diode of electric connection with the second input end in a voltage dividing circuit, to realize the positive half wave form detection of the first input end and the second input end, and output corresponding output electric signal to the first output end, and the electric signal of the first output end can control the photoelectric coupler to turn on or disconnect, and then adjust the electric signal of the open-phase detection output end, according to the electric signal pulse proportion of the open-phase detection output end, to determine the open-phase condition of three-phase power supply, so that, in the utility model, only one photoelectric coupler is set up, and the open-phase detection of three-phase power supply can be realized, the components and parts used are few, the circuit structure is simple, and the cost is low.
[0038] Optionally, Figure 5 The circuit structure schematic diagram of another open-phase detection circuit of three-phase power supply provided by the utility model embodiment is as shown in Figure 5 The first voltage dividing circuit 10 further includes a filter circuit 11, one end of the filter circuit 11 is electrically connected with the first output end O1, and the other end of the filter circuit 11 is electrically connected with the second output end O2.
[0039] In the utility model, the structure of the filter circuit 11 is not limited on the basis that the filter circuit 11 can realize the filtering function. In an optional embodiment, the filter circuit 11 includes a first capacitor C1.
[0040] Specifically, by setting the filter circuit 11 in the first voltage dividing circuit 10, the filter circuit 11 can filter out the noise of different frequencies or sizes existing in the electric signal of the first output end, so as to improve the signal-to-noise ratio of the electric signal of the first output end O1 and improve the reliability of the open-phase detection.
[0041] Optionally, Figure 6 The circuit structure schematic diagram of another open-phase detection circuit of three-phase power supply provided by the utility model embodiment is as shown in
[0042] Specifically, after the first voltage dividing circuit 10 divides the voltage of the first input end IN1 or the second input end IN2, the electric signal output to the first output end O1 is large, and the light-emitting diode 22 is easy to burn out. By setting the voltage protection circuit 12, when the voltage signal of the first output end O1 is high, the voltage protection circuit 12 can transmit the electric signal of the first output end O1 to the second resistor R2, and then transmit the electric signal to the third input end IN3 through the second resistor R2, so as to realize the function of discharging the electric signal of the first output end O1, protect the photoelectric coupler 20, and improve the working safety and reliability of the open-phase detection circuit.
[0043] In an optional embodiment, the voltage protection circuit 12 comprises a transient voltage suppression diode TVS; an anode of the transient voltage suppression diode TVS is electrically connected with the second output terminal O2, and a cathode of the transient voltage suppression diode TVS is electrically connected with the first output terminal O1.
[0044] Specifically, the transient voltage suppression diode TVS is an overvoltage protection device with bidirectional voltage stabilization characteristics and bidirectional negative resistance characteristics. When a surge pulse voltage occurs at the first output terminal O1 instantaneously, the transient voltage suppression diode can be quickly Zener broken down, and is changed from a high resistance state to a low resistance state, thereby shunting and clamping the surge voltage to protect the optocoupler 20 from being damaged by the instantaneous surge pulse voltage.
[0045] Optionally, Figure 7 A circuit structure schematic diagram of another three-phase power supply phase-loss detection circuit provided by the embodiment of the utility model is shown in Figure 7 The phase-loss detection circuit further comprises a second voltage dividing circuit 30; the second voltage dividing circuit 30 is electrically connected between the first end of the photosensitive element 21 and the phase-loss detection output terminal PL.
[0046] Specifically, the phase-loss detection output terminal PL can be connected with an oscilloscope or the like to obtain the voltage waveform of the phase-loss detection output terminal PL. When the voltage of the power supply VCC is relatively large, the electric signal provided to the phase-loss detection output terminal PL can exceed the working voltage of the oscilloscope or the like. Therefore, the second voltage dividing circuit 30 is arranged to adjust the voltage signal provided by the first end of the photosensitive element 21 to the phase-loss detection output terminal PL, so that the phase-loss detection circuit can be connected with the corresponding waveform detection device, and the practicability of the phase-loss detection circuit is improved.
[0047] Optionally, continuing to refer to Figure 7 The second voltage dividing circuit 30 comprises a fourth resistor R4 and a fifth resistor R5; a first end of the fourth resistor R4 is electrically connected with the first end of the photosensitive element 21, a second end of the fourth resistor R4 is electrically connected with a first end of the fifth resistor R5 and the phase-loss detection output terminal PL respectively, and a second end of the fifth resistor R5 is electrically connected with the ground terminal GND. In this way, the electric signal output to the phase-loss detection output terminal PL can be adjusted by setting appropriate resistance values of the fourth resistor R4 and the fifth resistor R5. The specific structure of the second voltage dividing circuit 30 can also be other, which is not limited here.
[0048] Based on the same utility model concept, the embodiment of the utility model provides a welding equipment, which comprises the three-phase power supply phase-loss detection circuit provided by any embodiment of the utility model, that is, comprises the technical features of the three-phase power supply phase-loss detection circuit described above, and therefore has the beneficial effects of the three-phase power supply phase-loss detection circuit, and the same parts can be referred to the description above.
[0049] It should be noted that the above only the preferred embodiments of the present application and the use of technical principles. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, those skilled in the art can make various obvious changes, re-adjust, mutual combination and replacement without departing from the scope of the present application. Therefore, although the above embodiments of the present application are described in more detail, but the present application is not limited to the above examples, without departing from the concept of the present application, it can also include more other equivalent embodiments, and the scope of the present application is determined by the appended claims.
Claims
1. A phase-loss detection circuit for a three-phase power supply, characterized by Comprising: The first voltage dividing circuit comprises a first diode, a second diode, a first resistor and a second resistor; the first voltage dividing circuit further comprises a first input end, a second input end, a third input end, a first output end and a second output end; the first input end is electrically connected with a first phase line of the three-phase power supply, the second input end is electrically connected with a second phase line of the three-phase power supply, and the third input end is electrically connected with a third phase line of the three-phase power supply; the anode of the first diode is electrically connected with the first input end, and the anode of the second diode is electrically connected with the second input end; the cathode of the first diode and the cathode of the second diode are both electrically connected with a first end of the first resistor, and a second end of the first resistor is electrically connected with the first output end; a first end of the second resistor is electrically connected with the third input end, and a second end of the second resistor is electrically connected with the second output end; The optoelectronic coupler comprises a photosensitive element, a light-emitting diode and a pull-up resistor; the anode of the light-emitting diode is electrically connected with the first output end, and the cathode of the light-emitting diode is electrically connected with the second output end; a first end of the pull-up resistor is electrically connected with a power supply, a second end of the pull-up resistor is electrically connected with a first end of the photosensitive element, and a second end of the photosensitive element is electrically connected with a ground end; the first end of the photosensitive element is electrically connected with a phase absence detection output end.
2. The phase failure detection circuit of claim 1, wherein, The first voltage dividing circuit further comprises a filter circuit; One end of the filter circuit is electrically connected with the first output end, and the other end of the filter circuit is electrically connected with the second output end.
3. The open-phase detection circuit of claim 1, wherein, The first voltage dividing circuit further comprises a voltage protection circuit; One end of the voltage protection circuit is electrically connected with the first output end, and the other end of the voltage protection circuit is electrically connected with the second output end.
4. The open-phase detection circuit of claim 2, wherein, The filter circuit comprises a first capacitor.
5. The open-phase detection circuit of claim 3, wherein, The voltage protection circuit comprises a transient voltage suppression diode; The anode of the transient voltage suppression diode is electrically connected with the second output end, and the cathode of the transient voltage suppression diode is electrically connected with the first output end.
6. The open-phase detection circuit of claim 1, wherein, Further comprising: A second voltage dividing circuit; The second voltage dividing circuit is electrically connected between the first end of the photosensitive element and the phase absence detection output end.
7. The phase failure detection circuit of claim 6, wherein, The second voltage dividing circuit comprises a fourth resistor and a fifth resistor; A first end of the fourth resistor is electrically connected with the first end of the photosensitive element, a second end of the fourth resistor is respectively electrically connected with a first end of the fifth resistor and the phase absence detection output end, and a second end of the fifth resistor is electrically connected with the ground end.
8. A welding apparatus characterized by, Comprising: The phase absence detection circuit of the three-phase power supply according to any one of claims 1-7.