CN217499651U - Facial line detection circuit, sewing machine control circuit and sewing machine - Google Patents

Abstract

The embodiment of the utility model provides a surface thread detection circuitry, sewing machine control circuit and sewing machine, surface thread detection circuitry includes: the upper thread optical coupler detection unit generates a pulse signal, and the upper thread passes through the optical coupler detection unit; the first square wave generating unit is connected with the output end of the upper thread optocoupler detection unit so as to convert the pulse signal into a first square wave signal; and the clock signal end of the D trigger is connected with the output end of the first square wave generation unit to generate a facial line breakage detection signal, and the circuit can find out whether the facial line is broken or not in time in the sewing process, so that the defects of line loss and abnormal stitch in the sewing process due to detection lag are avoided, and the sewing quality is improved.

Description

Facial line detection circuit, sewing machine control circuit and sewing machine

Technical Field

The embodiment of the utility model provides a sewing machine broken string detection area especially relates to a facial line detection circuitry, sewing machine control circuit and sewing machine.

Background

In the control of the industrial sewing machine, the condition of facial line breakage can occur in the sewing process of a user, the facial line breakage can be early warned through the facial line detection circuit, the sewing is stopped in time, and the pattern lines are prevented from being lost.

At present, the prior art can adopt a friction vibration method to realize the detection of facial line breakage. When the upper thread is broken, the upper thread still fluctuates due to the driving of the machine, if the difference between the fluctuation of the upper thread and the normal fluctuation is small, the breakage of the upper thread cannot be detected in time, and the problem of detection delay exists.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a facial line detection circuitry, sewing machine control circuit and sewing machine has solved the hysteretic problem of current facial line detection scheme detection.

In a first aspect, an embodiment of the present invention provides an upper thread detection circuit, include:

the upper thread optical coupler detection unit generates a pulse signal, and the upper thread passes through the optical coupler detection unit;

the first square wave generating unit is connected with the output end of the upper thread optocoupler detection unit so as to convert the pulse signal into a first square wave signal;

and the clock signal end of the D trigger is connected with the output end of the first square wave generating unit so as to generate an upper line disconnection detection signal.

Wherein, first square wave produces the unit and includes: the device comprises a first sawtooth wave generation module and a first comparator;

the first sawtooth wave generation module is connected with the output end of the upper thread optocoupler detection unit; the first sawtooth wave generation module is connected with the input end of the first comparator; the output end of the first comparator is connected with the D trigger.

Optionally, the first sawtooth wave generating module is an integrating amplifier.

The utility model provides a facial line detection circuitry, still includes luminous intensity the control unit, is connected with facial line opto-coupler detecting element's output and facial line opto-coupler detecting element's input respectively to according to facial line opto-coupler detecting element's output signal control facial line opto-coupler detecting element's luminous intensity.

The light emission intensity control unit includes: the second square wave generating unit and the control current intensity comparator;

the second square wave generating unit is connected with the output end of the upper thread optocoupler detection unit so as to convert the pulse signal into a second square wave signal;

the input end of the control current intensity comparator is connected with the output end of the second square wave generating unit and the output end of the first square wave generating unit respectively, and the output end of the control current intensity comparator is connected with the input end of the upper thread optocoupler detection unit.

The second square wave unit includes: the second sawtooth wave generating module and the second comparator;

the second sawtooth wave generation module is connected with the output end of the upper thread optical coupler detection unit; the second sawtooth wave generation module is connected with the input end of the second comparator; the output end of the second comparator is connected with the control current intensity comparator.

Optionally, the second sawtooth wave generating module is an integrating circuit.

The output end of the D trigger is also connected with the optical coupling isolation unit.

In a second aspect, an embodiment of the present invention provides a sewing machine control circuit, including: the face line detecting circuit according to any one of the first aspect, and a central processing unit;

the output end of the facial line detection circuit is connected with the central processing unit so as to output a facial line breakage detection signal to the central processing unit.

In a third aspect, embodiments of the present invention provide a sewing machine including a control circuit as in the second aspect.

The embodiment of the utility model provides a surface thread detection circuitry, sewing machine control circuit and sewing machine, the surface thread passes from surface thread opto-coupler detecting element, surface thread opto-coupler detecting element produces pulse signal, pulse signal input produces square wave signal behind the unit to first square wave, square wave signal input is to the clock signal end of D trigger, if the broken string appears in the surface thread then the output signal of D trigger can produce the level jump, produce the broken string detected signal promptly, thereby realize making up the in-process, can be accurate, in time detect out the surface thread broken string, improve and make up the quality.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a schematic diagram of an upper thread detection circuit provided in an embodiment of the present invention;

fig. 2 is a schematic diagram of another facial line detection circuit provided in the embodiment of the present invention;

fig. 3 is a schematic logic diagram of an upper thread detection circuit according to an embodiment of the present invention;

fig. 4 is a D flip-flop truth table provided by an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The terms "first," "second," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The nouns to which the present invention relates are explained first:

optical coupling: also known as a photo isolator or a photo coupler, is a device that transmits an electrical signal using light as a medium, and generally, a light emitter (an infrared light emitting diode LED) and a light receiver (a photosensitive semiconductor tube) are packaged in the same package. When the input end is powered on, the light emitter emits light, and the light receiver receives the light and then generates light current, which flows out from the output end, so that the conversion of electricity-light-electricity is realized.

Optical coupling isolation: because the light emitting diode in the optical coupler converts the input electrical signal into the optical signal and transmits the optical signal to the photosensitive tube to be converted into the electrical signal for output, and because no direct electrical connection exists, the optical coupler not only transmits the signal in a coupling manner, but also has an isolation effect.

D, a trigger: the memory is an information storage device with a memory function and two stable states, is the most basic logic unit for forming various sequential circuits, and is also an important unit circuit in a digital logic circuit.

An integration circuit: the circuit is a circuit for making an output signal proportional to a time integral value of an input signal, and is mainly used for waveform conversion, cancellation of offset voltage of an amplifier circuit, integral compensation in feedback control, and the like.

In order to solve the hysteretic problem of facial line broken string detection, the utility model provides a facial line detection circuitry, include: the device comprises a facial line optical coupler detection unit, a first square wave generation unit and a D trigger. The output end of the upper thread optical coupler detection unit is connected with the input end of the first square wave generation unit, and the output end of the first square wave generation unit is connected with the input end of the D trigger. The facial line passes from facial line opto-coupler detecting element, produces pulse signal, and first square wave produces the unit and converts pulse signal into first square wave signal, and first square wave signal is received to the clock signal end in the D trigger, if the facial line broken string appears, then the output signal of D trigger can produce the level jump, facial line broken string detected signal promptly to the realization is making the in-process, can be accurate, in time detect out whether the facial line breaks, improves and makes up the quality.

The technical solution of the present invention and how to solve the above technical problems will be described in detail with reference to specific embodiments. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments. Embodiments of the present invention will be described below with reference to the accompanying drawings.

Fig. 1 is the embodiment of the utility model provides a facial line detection circuitry sketch, as shown in fig. 1, facial line detection circuitry, include: the device comprises a facial line optical coupler detection unit 101, a first square wave generation unit 102 and a D trigger 103. The upper thread penetrates through the optical coupler detection unit 101 to generate a pulse signal; a first square wave generating unit 102 connected to an output end of the upper line photocoupler detecting unit 101 to convert the pulse signal into a first square wave signal; the clock signal terminal of the D flip-flop 103 is connected to the output terminal of the first square wave generating unit 102, and receives the first square wave signal. When the upper thread is broken, the output signal of the D flip-flop 103 generates a level jump, i.e., an upper thread breakage detection signal.

In the sewing process, the upper thread passes through the upper thread optical coupler detection unit 101. In the moving process of the upper thread, since the optical coupling detection unit 101 is a device for transmitting an electric signal by using light as a medium, when the input end of the optical coupling detection unit 101 is supplied with an electric signal, a light emitter in the optical coupling detection unit 101 emits light. Due to the movement and swing of the upper thread, a light emitting portion in the upper thread photo-coupling detecting unit 101 is intermittently shielded, thereby generating a pulse signal.

The pulse signal may be a voltage signal or a current signal. When the surface line shakes more or the moving speed is faster, the pulse signal generated by the surface line optical coupler detection unit 101 is relatively tighter. When the facial line shakes less or the moving speed is slower, the pulse signals generated by the facial line optical coupler detection unit 101 are relatively sparse.

The first square wave generating unit 102 is configured to convert the pulse signal output by the facial line photocoupler detection unit 101 into a square wave signal. The first square wave generating unit 102 may be composed of various forms of circuit elements, such as an integrating amplifier, a comparator, and the like.

The square wave signal output by the first square wave generating unit 102 is input into the D flip-flop 103, the clock signal terminal in the D flip-flop 103 receives the square wave signal, and if the upper thread is broken, the output signal of the D flip-flop 103 generates a level jump, that is, an upper thread breakage detection signal. The type of the D flip-flop 103 is not limited in this embodiment.

The embodiment of the utility model provides a facial line detection circuitry, include: the device comprises a facial line optical coupler detection unit 101, a first square wave generation unit 102 and a D trigger 103. The upper thread penetrates through the upper thread optical coupling detection unit 101 to generate a pulse signal. The first square wave generating unit 102 receives the pulse signal and converts the pulse signal into a first square wave signal. The clock signal end in the D flip-flop 103 receives the first square wave signal, and when the facial line is broken, the output signal of the D flip-flop 103 generates a level jump, that is, a facial line broken detection signal, which can find the facial line broken in time.

In order to improve the accuracy and timeliness of facial line monitoring, the facial line detection circuit provided by the above embodiment further includes a light emission intensity control unit. Fig. 2 is a schematic diagram of another embodiment of the upper line detecting circuit provided by the present invention, and the following describes the light intensity control unit in detail with reference to fig. 2.

And the luminous intensity control unit 201 is respectively connected with the output end of the upper thread optical coupler detection unit 101 and the input end of the upper thread optical coupler detection unit 101 so as to control the luminous intensity of the upper thread optical coupler detection unit 101 according to the output signal of the upper thread optical coupler detection unit 101. Under the condition that the shake of the upper thread is large or the moving speed is high, the luminous intensity of the upper thread optocoupler detection unit 101 is strong and is kept unchanged, if the upper thread is broken, the shake of the broken thread can possibly interfere with the pulse signal output by the upper thread optocoupler detection unit 101, and therefore the upper thread can not be accurately and timely detected. Under the condition that the shake of the upper thread is small or the moving speed is low, the luminous intensity of the upper thread optocoupler detection unit 101 is very weak and is kept unchanged, because the light intensity is weak, the upper thread optocoupler detection unit 101 cannot detect the tiny operation of the upper thread, the pulse signal is not output any more, and therefore the thread breakage is judged by mistake. In order to improve the accuracy and timeliness of the facial line detection, the luminous intensity of the facial line opto-coupler detection unit 101 needs to be controlled according to the facial line moving speed, namely the output signal of the facial line opto-coupler detection unit 101.

As shown in fig. 2, the light-emitting intensity control unit 201 may be composed of a current intensity detection circuit and a current intensity control circuit, wherein the current intensity detection circuit is configured to detect whether the current intensity of the facial line opto-coupler detection unit 101 satisfies a threshold, and if not, adjust the current intensity of the facial line opto-coupler detection unit 101 through the current intensity control circuit.

As a possible embodiment, the light intensity control unit 201 may include: a second square wave generating unit 2011 and a control current intensity comparator 2012.

The second square wave generating unit 2011 is connected to the output end of the upper line optical coupler detecting unit 101, so as to convert the pulse signal into a second square wave signal. The second square wave generating unit 2011 is configured to convert the pulse signal output by the upper line photocoupler detecting unit 101 into a square wave signal, similarly to the function of the first square wave generating unit 102.

The second square wave generating unit 2011 may also be composed of various types of elements capable of generating a square wave signal. Alternatively, the second square wave generating unit 2011 may include: a second sawtooth wave generation module and a second comparator.

The second sawtooth wave generation module is connected with the output end of the upper thread optical coupler detection unit 101; the second sawtooth wave generation module is connected with the input end of the second comparator; the output of the second comparator is connected to a control current strength comparator 2012. Since the luminous intensity control unit 201 controls the luminous intensity of the facial line opto-coupler detection unit 101 according to the output signal of the facial line opto-coupler detection unit 101, the components of the first square wave generation unit 102 and the second square wave generation unit 2011 are different, that is, the current intensity of the facial line opto-coupler detection unit 101 is detected by comparing the difference between the output signals of the first square wave generation unit 102 and the second square wave generation unit 2011, and the current intensity of the facial line opto-coupler detection unit 101 is adjusted according to the detection result.

Therefore, the second sawtooth wave generation module can be an integrating circuit and converts the pulse signal into the sawtooth wave. The second comparator compares the sawtooth wave with a reference value to generate a second square wave signal.

The reference value in the second comparator may be set according to specific requirements, for example: may be 50% of the operating voltage of the face line photocoupler detection unit 101.

The input end of the control current intensity comparator 2012 is connected with the output end of the second square wave generating unit 2011 and the output end of the first square wave generating unit 102, respectively, and the output end of the control current intensity comparator 2012 is connected with the input end of the upper line opto-coupler detecting unit 101.

The control current intensity comparator 2012 receives the first square wave signal and the second square wave signal, detects the current intensity of the facial line opto-coupler detecting unit 101 by comparing the output signal difference between the first square wave generating unit 102 and the second square wave generating unit 2011, and adjusts the current intensity of the facial line opto-coupler detecting unit 101 according to the detection result.

The signal output from the upper line spectrum detection unit 101 may be output to the control current intensity comparator 2012 through the second square wave generation unit 2011, and compared with the reference level. The reference level may be a signal output by the first square wave generating unit 102, and the magnitude of the reference level may be affected by the frequency of the signal output by the upper line optical coupler detecting unit 101. When the frequency of the output signal of the surface line optical coupling detection unit 101 becomes high, the reference level value rises, so that the time for the comparator 2012 for controlling the current intensity to output a high level is reduced, the on-time of the triode at the port of the input end of the surface line optical coupling detection unit 101 is reduced, and the current input to the input end of the surface line optical coupling detection unit 101 is reduced. It can be understood that when the frequency of the output signal of the surface line optical coupling detection unit 101 becomes low, the reference level value is reduced, so that the time for controlling the output of the high level by the comparator 2012 of the current intensity is increased, the on-time of the triode at the port of the input end of the surface line optical coupling detection unit 101 is prolonged, and the current at the input end of the surface line optical coupling detection unit 101 is increased.

Under an implementation scene, when the facial line shake is great or the translation rate is very fast, facial line opto-coupler detecting element 101 produces comparatively inseparable pulse signal relatively, the current value that can carry for facial line opto-coupler detecting element 101 through the comparator 2012 control current intensity diminishes, thereby lead to facial line opto-coupler detecting element 101 luminous intensity to weaken, make facial line opto-coupler detecting element 101 have a more weak luminous intensity just can detect the motion of facial line, can avoid when luminous intensity is stronger, the problem that can not in time detect out the facial line broken string because the pulse signal of shake facial line opto-coupler detecting element 101 output that the broken string appears produces the interference, can effectively detect the facial line motion, can effectively reduce the problem that can not detect out after the facial line broken string again.

Under another kind of implementation scenario, when the facial line shake is less or the translation rate is slower, facial line opto-coupler detecting element 101 produces comparatively sparse pulse signal, can control the current value grow of carrying for facial line opto-coupler detecting element 101 through comparator 2012 of control current intensity for facial line opto-coupler detecting element 101 has stronger luminous intensity, can avoid because of the weak small operation that can not effectively detect out the facial line of luminous intensity, the mistake of wrong report facial line broken string appears, the accuracy that improves the facial line and detects.

The embodiment of the utility model provides a facial line detection circuitry. In order to improve the accuracy and timeliness of the face line detection, the face line detection circuit further includes a light emission intensity control unit 201. The upper thread optical coupler detection unit 101 outputs a pulse signal, the second sawtooth wave generation module converts the pulse signal into sawtooth waves, and the sawtooth waves are compared with a reference value through a second comparator to generate a second square wave signal. The control current intensity comparator 2012 receives the first square wave signal and the second square wave signal, and adjusts the current intensity of the upper line opto-coupler detecting unit 101 by comparing the difference between the first square wave signal and the second square wave signal, thereby controlling the luminous intensity of the upper line opto-coupler detecting unit 101. When the upper thread moving speed is high, the luminous intensity of the upper thread optical coupler detection unit 101 is low, the upper thread breakage can be found in time, and the sensitivity is improved. When the moving speed of the upper thread is relatively low, the luminous intensity of the upper thread optocoupler detection unit 101 is enhanced, the micro operation of the upper thread is effectively detected, the false alarm of the breakage of the upper thread is prevented, and the detection accuracy of the upper thread is improved.

On the basis of the above embodiment, the face line detection circuit of the present application will be described in detail below by a specific embodiment with reference to fig. 3. Fig. 3 is a logic schematic diagram of the facial line detection circuit provided by the embodiment of the present invention, which introduces the working principle of the D flip-flop and the optical coupling isolation unit in the facial line detection circuit in detail.

A facial thread optical coupler detection unit is arranged on a sewing machine head, and facial threads pass through the facial thread optical coupler detection unit and output pulse signals.

In the sewing process, the upper thread moves rapidly, in the moving process, because the movement and the swing of the upper thread cause discontinuous shielding to the luminous part in the upper thread optocoupler detection unit, a series of pulse signals are formed at the output end of the upper thread optocoupler detection unit, and the pulse signals generate wave forms with alternate density along with the moving speed and the swing amplitude of the upper thread. When the facial line moving speed is faster, the pulse signal output by the facial line optical coupler detection unit is more compact relatively. When the moving speed of the facial line is low, pulse signals output by the facial line optical coupling detection unit are relatively sparse.

The pulse signal may represent a voltage signal.

The first square wave generating unit is connected with the output end of the upper thread optical coupler detection unit, receives the pulse signal output by the upper thread optical coupler detection unit and converts the pulse signal into a first square wave signal.

The first square wave generating unit may be composed of various types of circuit elements capable of generating square wave signals. Optionally, the first square wave generating unit may include: the device comprises a first sawtooth wave generation module and a first comparator.

The first sawtooth wave generation module is connected with the output end of the upper thread optocoupler detection unit; the first sawtooth wave generation module is connected with the input end of the first comparator.

Specifically, the first sawtooth wave generation module may be composed of various elements capable of generating sawtooth wave signals, for example, the first sawtooth wave generation module may be an integrating amplifier.

The upper thread optical coupler detection unit generates sparse and dense waveform signals, generates a first sawtooth wave signal through the integrating amplifier, generates a first square wave signal after the first sawtooth wave signal is compared with a reference value through the first comparator, and outputs the first square wave signal to a CLOCK signal (CLOCK signal) of the D trigger.

The D trigger is connected with the output end of the first comparator, a clock signal end in the D trigger receives a first square wave signal from the first comparator, and if the upper thread is broken, the output signal of the D trigger generates level jump, namely an upper thread broken detection signal.

The type of the D flip-flop is not limited in this embodiment, and as a possible implementation, the truth table of the D flip-flop referred to in this application may be as shown in fig. 4.

In combination with the actual design of the circuit, D is set to 1, S is set to 0, and R changes the high level and the low level.

When the CLOCK signal has a rising edge, according to the truth table, R is 0, so the Q output signal is high and the/Q output signal is low.

When the CLOCK signal has a falling edge, R and S are unchanged, and remain low, and the state of the Q output signal and/or the Q output signal remains unchanged.

When the planar optical coupler detection unit generates a pulse signal, the CLOCK signal can be triggered by the D flip-flop regardless of density, and the R signal is controlled to be unchanged to 1, namely R is equal to 0, by adjusting the RC time constant, the Q and/Q output signals are not changed, the Q output signal is still kept at a high level, and the/Q output signal is at a low level.

The output end of the D trigger is further connected with an optical coupling isolation unit, and the output end of the optical coupling isolation unit is connected with the central processing unit. The optical coupling isolation unit carries out optical coupling isolation on the facial line detection signal output by the D trigger, and then outputs the processed facial line breakage detection signal to the central processing unit.

Because the central processing unit receives a specific voltage signal, the output signal of the D trigger, namely the facial line breakage detection signal, needs to be isolated by the optical coupling isolation unit, and the optical coupling isolation unit outputs the processed facial line breakage detection signal to the central processing unit.

Optionally, the optical coupling isolation unit may include: triode, current-limiting resistor, optical coupler and power supply.

The pin of the optical coupler 1 is connected with a power supply, the pin of the optical coupler 2 is connected with a current-limiting resistor and a triode, and the Q signal output by the D trigger controls the on-off of the triode so as to control whether the optical coupler is switched on or not.

When the Q signal output by the D trigger is low level, the triode is in a turn-off state, the optocoupler is turned off, the triode in the optocoupler is also in a turn-off state, and then the signal output to the central processing unit is a low level signal.

When the Q signal output by the D trigger is at a high level, the triode is switched on, the optocoupler is switched on, the triode in the optocoupler is switched on, and then the signal output to the central processing unit is a high-level signal.

The RC time constant can be set according to specific requirements, and the state of the R signal can be controlled by adjusting the RC time constant, so that whether the Q signal and/or the Q signal output by the D trigger generate level jump or not is controlled.

When the upper thread shakes or moves, the upper thread optical coupler detection unit outputs a pulse signal, the capacitor discharges while charging, and R is kept in a 0 state, so that the upper thread optical coupler detection unit is not influenced by an RC time constant.

When the facial line is broken, the output signal of the facial line optical coupler detection unit does not generate a pulse signal any more, the first comparator does not generate a first square wave signal and outputs the first square wave signal to the D trigger, therefore, the level signal does not change in RC time, when the time constant controlled by RC is exceeded, the voltage output by Q charges the capacitor through the resistor, at the moment, the capacitor only charges and does not discharge, when the capacitor is fully charged, R changes to 1, Q output is low level, and/Q output is high level, and level jump is generated.

The embodiment of the utility model provides a facial line detection circuitry, facial line opto-coupler detecting element output pulse signal, first square wave produces the unit and converts pulse signal into first square wave signal, and first square wave signal is received to the clock signal end of D flip-flop, if the condition of broken string appears in the facial line, the output signal of D flip-flop can produce the level jump, and facial line broken string detects the signal promptly, after the unit processing is kept apart to the opto-coupler, with facial line broken string detection signal output for central processing unit. The central processing unit receives the upper thread breakage detection signal, and gives an alarm in time to stop sewing.

The application provides a sewing machine control circuit, which comprises the upper thread detection circuit and the central processing unit in the embodiment.

The output end of the facial line detection circuit is connected with the central processing unit so as to output a facial line breakage detection signal to the central processing unit.

The upper thread detection signal transmitted to the central processing unit may be a high level signal or a low level signal.

For example, it may be set that the upper thread detecting circuit outputs a low level signal to the central processing unit when the upper thread is not broken. When the upper thread is broken, the upper thread detection circuit outputs a high level signal to the central processing unit.

When the surface thread is broken, the central processing unit receives a high level signal from the surface thread detection circuit, gives an alarm to inform the user of stopping sewing, and can prevent the cloth from being damaged and the stitches from being abnormal.

The application provides a sewing machine, includes: the control circuit in the above embodiment.

In the several embodiments provided in the present application, it should be understood that the disclosed circuits and devices may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims (10)

1. A face line detection circuit, comprising:

the upper thread optical coupler detection unit generates a pulse signal, and the upper thread passes through the optical coupler detection unit;

the first square wave generating unit is connected with the output end of the upper thread optocoupler detection unit so as to convert the pulse signal into a first square wave signal;

and the clock signal end of the D trigger is connected with the output end of the first square wave generating unit so as to generate an upper line disconnection detection signal.

2. The circuit according to claim 1, wherein the first square wave generating unit includes: the device comprises a first sawtooth wave generation module and a first comparator;

the first sawtooth wave generating module is connected with the output end of the facial line optical coupling detection unit; the first sawtooth wave generation module is connected with the input end of the first comparator; and the output end of the first comparator is connected with the D trigger.

3. The circuit of claim 2, wherein the first sawtooth generation module is an integrating amplifier.

4. The circuit of any of claims 1-3, further comprising:

and the luminous intensity control unit is respectively connected with the output end of the upper thread optical coupler detection unit and the input end of the upper thread optical coupler detection unit so as to control the luminous intensity of the upper thread optical coupler detection unit according to the output signal of the upper thread optical coupler detection unit.

5. The circuit according to claim 4, wherein the light emission intensity control unit comprises: the second square wave generating unit and the control current intensity comparator;

the second square wave generating unit is connected with the output end of the upper thread optocoupler detection unit so as to convert the pulse signal into a second square wave signal;

the input end of the control current intensity comparator is connected with the output end of the second square wave generating unit and the output end of the first square wave generating unit respectively, and the output end of the control current intensity comparator is connected with the input end of the upper thread optical coupler detection unit.

6. The circuit according to claim 5, wherein the second square wave generating unit comprises: the second sawtooth wave generating module and the second comparator;

the second sawtooth wave generation module is connected with the output end of the upper thread optical coupler detection unit; the second sawtooth wave generation module is connected with the input end of the second comparator; and the output end of the second comparator is connected with the control current intensity comparator.

7. The circuit of claim 6, wherein the second sawtooth generation module is an integration circuit.

8. The circuit of claim 1, wherein the output end of the D flip-flop is further connected with an optical coupling isolation unit.

9. A sewing machine control circuit, comprising: the upper line detecting circuit as claimed in any one of claims 1 to 8, and a central processing unit;

the output end of the facial line detection circuit is connected with the central processing unit so as to output the facial line breakage detection signal to the central processing unit.

10. A sewing machine characterized by comprising the control circuit of claim 9.

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