Summary of the invention
The object of the present invention is to provide a kind of screening machine and its power control circuits, carry out power supply control without using contactor
System, and reduces use the number of relay, at low cost, and can avoid contact with device as far as possible and relay contact works causes
Sparking interference and back-emf caused by interfere, the accuracy of safety check machine testing is high.
In order to solve the above technical problems, the present invention provides a kind of power control circuits of screening machine, including:Key is opened
Pass, start button, master switch pipe, first switch tube, the first photoelectrical coupler first resistor and the first relay;
Wherein, the key switch is connected with the start button, and the first end of the circuit after series connection is separately connected direct current
The first end of positive pole and the master switch pipe, the second end of the circuit after series connection connect the control of the first switch tube
End;
Between the second end and DC power cathode of the master switch pipe and it is connected to each control assembly of the screening machine
And work package series circuit, if be in series in the work package series circuit first relay coil-end and
Dry scram button;The contact both ends of first relay are separately connected the work package of general supply Yu the screening machine;Institute
State the switching on and shutting down signal end that key switch connects the control panel of the screening machine;
The control terminal of the master switch pipe be separately connected the first switch tube first end and the first photoelectricity coupling
The positive output end of clutch;
The second end of the first switch tube, the negative input end of first photoelectrical coupler and negative output terminal are all connected with directly
Galvanic electricity source negative pole end;
The positive output end of first photoelectrical coupler connects the first end of the first resistor, and the of the first resistor
Two ends are separately connected the second end of the master switch pipe and the shutdown control signal output of the control panel;The control panel
It receives output after the key switch is placed in the off signal sent when OFF position and closes machine control signal.
It preferably, further include second resistance;
The second end of the first resistor is directly connected to the shutdown control signal output of the control panel, and passes through institute
State the second end that second resistance connects the master switch pipe.
Preferably, further include:Second switch, the second photoelectrical coupler, third photoelectrical coupler, 3rd resistor, the 4th
Resistance and the 5th resistance;
The first end of the second switch is separately connected the positive input terminal of the third photoelectrical coupler, and passes through institute
State the positive input terminal that 3rd resistor connects second photoelectrical coupler;The second end connection of the second switch is described always to open
Close the second end of pipe;
The negative input end of second photoelectrical coupler connects the second switch by the 5th resistance respectively
First positive and negative rotation signal output end of control terminal and the control panel;
Second positive and negative rotation signal output end of the control panel is separately connected the positive input terminal of second photoelectrical coupler,
And the negative input end of the third photoelectrical coupler is connected by the 4th resistance;
The output end of second photoelectrical coupler connects the rotating forward control terminal of the electric machine controller of the screening machine, described
The output end of third photoelectrical coupler connects the reversion control terminal of the electric machine controller;The control panel receives the key
Machine control signal is closed in output after the off signal that switch is sent when being placed in OFF position.
It preferably, further include the second relay;
The coil-end of second relay is serially connected between the second end and DC power cathode of the master switch pipe, institute
The contact both ends for stating the second relay are separately connected the display of general supply and screening machine, and second relay is for controlling
On-off between the display and the general supply.
Preferably, the master switch pipe is metal-oxide-semiconductor, and the first auxiliary electricity is connected between the source electrode and grid of the metal-oxide-semiconductor
Resistance, is serially connected with the 6th resistance between the control terminal of the master switch pipe and the first end of the first switch tube.
Preferably, the first switch tube is triode, is connected between the base stage and emitter of the first switch tube
Second auxiliary resistance.
Preferably, the second switch is triode, is connected between the base stage and emitter of the second switch
Third auxiliary resistance;The 7th resistance is serially connected between the control terminal of the second switch and the 5th resistance.
Preferably, the key switch is connect with the switching on and shutting down signal input part of the control panel, and the key switch is set
Off signal is sent when OFF position to the control panel, output shutdown control after the control panel delay predetermined time period
Signal.
In order to solve the above technical problems, the present invention also provides a kind of screening machine, including it is control assembly, work package, aobvious
Show device, several scram buttons and the power control circuit as described in any of the above item;
Wherein, the control assembly includes control panel;The work package includes radiographic source and Rolling motor.
Preferably, the control panel is connect with the scram button and the display respectively, and the control panel is used for
After detecting that scram button is pressed, output stop signal to the display;
After the display receives the stop signal, the prompt of display scram button triggering.
The present invention provides a kind of power control circuit of screening machine, including key switch, start button, master switch pipe,
It is positive and negative that first switch tube, the first photoelectrical coupler and first resistor, master switch pipe and first switch tube are serially connected with DC power supply
Between pole, the first photoelectrical coupler is in parallel with first switch tube, and first resistor is used to export in the pass machine control signal of control panel
After machine control signal is closed in end output, the voltage of the positive input terminal of the first photoelectrical coupler is dragged down, then photoelectrical coupler is just defeated
Outlet becomes high level by low level, and the control terminal of master switch pipe is high level, the cut-off of master switch pipe, screening machine shutdown.At this
It invents in the power control circuit provided, after key switch and start button starting, the control terminal connection of first switch tube is straight
Flow positive pole, the second end of first switch tube connects DC power cathode, therefore the control terminal of first switch tube and second end it
Between form pressure drop, to make first switch tube be connected, later due to the control terminal of master switch pipe and the first end of first switch tube
Connection, the first end of master switch pipe connect DC power anode, therefore, shape between the control terminal and first end of master switch pipe at this time
At pressure drop, the conducting of master switch pipe is connected between the second end and DC power anode of master switch pipe, therefore is connected to master switch pipe
Second end and DC power cathode between the equal work once electrified of all components, and after the electrification of the coil-end of the first relay, the
The contact both ends of one relay are connected, therefore also work once electrified after the work package of screening machine connection general supply.Later, work as control panel
After machine control signal is closed in output, got higher since the level of positive input terminal of the first photoelectrical coupler can be dragged down by low, it can lead
It causes the first photoelectric coupler output end to end, so that master switch pipe ends, and then keeps all components of rear end screening machine equal
Have a power failure shutdown.
It can be seen that the present invention does not need that multiple relays and contactor is arranged to realize power supply control (i.e. switching on and shutting down
Control) purpose, but three switching tubes and photoelectrical coupler and several resistance are used only, it is at low cost, and energy
It is enough to avoid contact with sparking interference caused by device and relay contact work as far as possible, it is generated there are also contactor or relay coil
It is interfered caused by back-emf, the accuracy of safety check machine testing is high.The present invention also provides a kind of screening machines, it may have above-mentioned excellent
Point, details are not described herein.
Specific embodiment
Core of the invention is to provide a kind of screening machine and its power control circuit, carries out power supply control without using contactor
System, and reduces use the number of relay, at low cost, and can avoid contact with device as far as possible and relay contact works causes
Sparking interference and back-emf caused by interfere, the accuracy of safety check machine testing is high.
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present invention
In attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is
A part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art
Every other embodiment obtained without making creative work, shall fall within the protection scope of the present invention.
Shown in Figure 4 the present invention provides a kind of power control circuit of screening machine, Fig. 4 is provided by the invention one
The structural schematic diagram of the power control circuit of kind screening machine.
The power control circuit includes:Key switch, start button, master switch pipe Q, first switch tube Q1, the first photoelectricity
Coupler U1, first resistor R1 and the first relay K1;
Wherein, key switch is connected with start button, and the first end of the circuit after series connection is separately connected DC power anode
And the first end of master switch pipe Q, the control terminal of the second end connection first switch tube Q1 of the circuit after series connection;Key switch connects
Connect the switching on and shutting down signal end of the control panel of the screening machine;
Between the second end and DC power cathode of master switch pipe Q and it is connected to each control assembly and work of screening machine
Component series circuit is in series with the coil-end and several scram buttons of the first relay K1 in work package series circuit;
First contact relay K1 both ends is separately connected the work package of general supply and screening machine;
First end that the control terminal of master switch pipe Q is separately connected first switch tube Q1 and the first photoelectrical coupler U1 are just
Output end;
The second end of first switch tube Q1, the negative input end of the first photoelectrical coupler U1 and negative output terminal are all connected with direct current
Source negative pole end;
The first end of the positive input terminal connection first resistor R1 of first photoelectrical coupler U1, the second end point of first resistor R1
It Lian Jie not the second end of master switch pipe Q and the shutdown control signal output of control panel;Control panel receives key switch and sets
Machine control signal is closed in output after the off signal sent when OFF position.
Here general supply is commonly referred to as 220V alternating current;DC power supply is commonly referred to as 12V DC electricity.Certainly, originally
Invention does not limit the voltage value of general supply and DC power supply.
It should be noted that the first relay K1 in the present invention is the normal-open type relay of 2 contacts, it is powered latter two
Contact can be closed conducting.
Wherein, the course of work of above-mentioned power control circuit is, when key switch is placed in the position ON and presses start button
Afterwards, the control terminal of first switch tube Q1 can be connected to DC power anode, since the second end of first switch tube Q1 connects direct current
Power cathode, so when first switch tube Q1 control terminal and second end between form pressure drop, so that first switch tube Q1 be made to lead
It is logical;Later since the control terminal of master switch pipe Q is connect with the first end of first switch tube Q1, the first end of master switch pipe Q is connected
Therefore DC power anode forms pressure drop, master switch pipe Q conducting at this time between the control terminal and first end of master switch pipe Q;I.e.
Be connected between the second end and DC power anode of master switch pipe Q, thus be connected to master switch pipe Q second end and DC power supply it is negative
The equal work once electrified of all components between pole, and after the electrification of the coil-end of the first relay K1, the contact two of the first relay K1
End conducting (contact closure), therefore the work package of screening machine connects general supply, thus work once electrified.At this time screening machine integrally it is electric
It starts to work.Later, it due to the positive input terminal of the first photoelectrical coupler U1 and first switch tube Q1 and connects, therefore master switch pipe is connected
Afterwards, the positive input terminal of U1 forms pressure drop by R1 and negative input end, and then the output end of the first photoelectrical coupler U1 is connected and connects
The control terminal on ground, master switch pipe Q continues to low level, so that master switch pipe Q be made to be continuously on state.
And when wanting shutdown, key switch is placed in OFF position, due to the switching on and shutting down signal end of key switch and control panel
Connection, key switch, which is placed in after OFF position, can send off signal come after informing that control panel, control panel receive off signal,
Pass machine control signal can be exported, pass machine control signal here is low level signal, is exported in the pass machine control signal of control panel
After machine control signal is closed in end output, the voltage that machine control signal drags down the positive input terminal of the first photoelectrical coupler U1 is closed.Specific work
It is as process, since the pressure drop of master switch pipe Q first end and second end is definite value, after master switch pipe Q conducting, second end
Voltage value then fixed (metal-oxide-semiconductor is that conducting resistance is very low, so the pressure drop of first end and second end is almost 0) master switch pipe Q
Second end the positive input terminal of the first photoelectrical coupler U1 is connect with second resistance R2 by concatenated first resistor R1.Later,
After control panel exports the tie point for closing machine control signal to first resistor R1 and second resistance R2, it is due to closing machine control signal
Low level signal, therefore the positive input terminal of the first photoelectrical coupler U1 is low level, the first photoelectrical coupler U1 output at this time is cut
Only, the control terminal of master switch pipe Q becomes high level, master switch pipe Q cut-off from low level, and then makes whole groups of rear end screening machine
Part has a power failure shutdown.
It can be seen that the present invention does not need setting contactor to realize the purpose of power supply control, and reduce relay
Using number, but three switching tubes, photoelectrical coupler, several resistance and a relay is used only, it is at low cost,
And sparking interference caused by device or relay contact work can be avoided contact with as far as possible, there are also contactors or relay coil to produce
It is interfered caused by raw back-emf, the accuracy of safety check machine testing is high.
In addition, since the coil-end of the first relay K1 and several scram buttons are serially connected with the second end of master switch pipe Q
Between DC power cathode, when staff presses scram button or removes side door plate touch microswitch, the work
Component series circuit will disconnect, so that the coil-end power loss of the first relay K1, contact both ends are disconnected, so that first
It is powered off between the work package and general supply of the screening machine that relay K1 is connected, to realize protection staff and equipment peace
Full purpose.Wherein scram button here may include that several common tightly stop button and door-plate microswitch (that is, door-plate
The touch-switch for pressing against and being closed) etc., this is not limited by the present invention.Here work package may include X source, roller electricity
Machine, radiator fan etc., this is not limited by the present invention.
Wherein, above-mentioned control assembly includes control panel, sampling plate and industrial personal computer;Above-mentioned work package includes radiographic source, rolling
Cylinder motor and fan.Certainly, control assembly and work package may also include other component, and which is not limited by the present invention.
In a preferred embodiment, above-mentioned power control circuit further includes second resistance R2;
The second end of first resistor R1 is directly connected to the shutdown control signal output of control panel, and passes through second resistance
The second end of R2 connection master switch pipe Q.
It is understood that first resistor R1 and second resistance R2 are for being using two resistance as current-limiting resistance
The first photoelectrical coupler U1 is damaged in the case where wrong line in order to prevent.
In the Rolling motor control process for carrying out screening machine, it usually needs control the positive and negative rotation of Rolling motor, control at present
The circuit of Rolling motor positive and negative rotation processed is realized by the way that multiple relays and contactor is arranged, as shown in Figures 2 and 3, figure
2 be the structural schematic diagram of the motor positive inversion control circuit part on current screening machine power panel circuit;Fig. 3 is current screening machine
The structural schematic diagram of circuit for controlling motor part on power panel circuit;Relay KA2 and KA3 lead to contactor KM2 after being attracted
It is attracted, so that this circuit in Fig. 2 where the both ends of the contact KM2 be made to remain conducting;Referring to Fig. 3, after KM2 is attracted, in Fig. 3
The contact both ends of KM2 are connected, Rolling motor starting.Relay KA4, KA5 are controlled by control panel, when control panel is receiving motor just
When the signal turned, the contact closure of KA4, the contact KA5 1 and contact 5 are closed, and 1 foot and 5 feet on DC motor controller are shorted,
Rolling motor rotates forward.When control panel receives the signal of motor reversal, the contact closure of KA4, the contact KA5 1 and contact 3 are closed
It closes, 1 foot and 7 feet on DC motor controller are shorted, Rolling motor reversion.In this control circuit, need to be arranged it is multiple after
Electric appliance and contactor, circuit structure is complex and costly, and the contact on-off of relay and contactor will also result in it is larger
Interference.
To solve the above problems, the present invention provides a kind of preferred embodiments, in this embodiment, power control circuit is also
Including:Second switch Q2, the second photoelectrical coupler U2, third photoelectrical coupler U3,3rd resistor R3, the 4th resistance R4 and
5th resistance R5;
The first end of second switch Q2 is separately connected the positive input terminal of third photoelectrical coupler U3, and passes through third electricity
Hinder the positive input terminal of the second photoelectrical coupler of R3 connection U2;The second end of the second end connection master switch pipe Q of second switch Q2;
The negative input end of second photoelectrical coupler U2 passes through the control terminal of the 5th resistance R5 connection second switch Q2 respectively
And the first positive and negative rotation signal output end of control panel;
Second positive and negative rotation signal output end of control panel is separately connected the positive input terminal of the second photoelectrical coupler U2, Yi Jitong
Cross the negative input end of the 4th resistance R4 connection third photoelectrical coupler U3;
The rotating forward control terminal of the electric machine controller of the output end connection screening machine of second photoelectrical coupler U2, third photoelectricity coupling
The reversion control terminal of the output end connection electric machine controller of clutch U3.
It is understood that the purpose of the present embodiment is the positive and negative rotation in order to control Rolling motor, specific work process
For:When needing Rolling motor to rotate forward, control panel exports the first positive and negative rotaring signal, and the first positive and negative rotaring signal is low level, referring to
Shown in Fig. 4, i.e. 7 feet in Fig. 4 are low level, and control panel does not export the low level second positive and negative rotaring signal at this time, therefore 8 feet are
High level.At this time since 7 feet are low level, therefore the control terminal of Q2 is low level, Q2 conducting, the high electricity of positive input terminal access of U2
Flat, the input terminal of U2 forms pressure drop, the conducting of U2 output end, i.e. rotating forward control terminal (i.e. 0 foot and a in Fig. 4 of electric machine controller
Foot) it is shorted conducting, control motor rotates forward.
When needing Rolling motor to invert, it is low level that control panel, which exports the first positive and negative rotaring signal, while exporting second just
Reverse signal is low level, and 7 feet and 8 feet are low level at this time;Due to 7 foot low levels, the control terminal of Q2 is low level, and Q2 is led
It is logical, but the positive input terminal of U2 is dragged down due to being connected with 8 feet, U2 cut-off.The first end of the positive input terminal connection Q2 of U3, U3's
Negative input end is low level by 8 foot of resistance R4 connection, forms pressure drop, U3 conducting, the output end conducting of U3, i.e. electric machine controller
Reversion control terminal (i.e. 9 feet and a foot in Fig. 4) be shorted conducting, control motor reversal.
The present embodiment is by a switching tube, two photoelectrical couplers and several resistance and realizes control roller electricity
The function of machine positive and negative rotation in this structure does not need that multiple contactors and relay is arranged, and not only cost is relatively low, wiring compared with
To be simple, and sparking interference caused by relay and contacts of contactor can be avoided as far as possible, to improve peace as far as possible
The accuracy of inspection machine safety check.
It is further known that as shown in figure 4, above-mentioned power control circuit further includes the second relay K2;
The coil-end of second relay K2 is serially connected between the second end and DC power cathode of master switch pipe Q, second after
The contact both ends of electric appliance K2 are separately connected the display of general supply and screening machine, the second relay K2 for control display with
On-off between general supply.
Control the on-off of work package it is understood that enabling with the concatenated first relay K1 of scram button, be for
After guaranteeing that scram button is pressed, these work packages can be realized power-off, and control assembly and display do not need then to power off.
This is because the case where usually pressing scram button, the main feelings including may be subjected to staff's touching inside screening machine
Condition, at this time by the general supply that the connected power supply of the work packages such as radiographic source, Rolling motor and fan is 220V, and Rolling motor
And fan can rotate and work, if its still live line work, may bring danger to staff, and display or
Person is not had above-mentioned danger then by the control assembly that DC power supply is powered, and therefore, when emergency occurs, is usually only necessary to
Work package power-off is controlled, therefore these work packages are connect with the first relay K1 controlled by scram button,
And remaining needs to connect the device of general supply, such as display can then be connect with the second relay K2.
Certainly, if the second relay K2 can also be not provided in the purpose for reducing screening machine wiring and number of devices, and
All the component powered by general supply will be needed to connect with the first relay K1.It is specific to use which kind of above mode present invention not
It limits.
It should be noted that it should be noted that the second relay K2 in the present invention is the open type relay of 2 contacts
Device, latter two contact that is powered can be closed conducting.
It is further known that master switch pipe Q is metal-oxide-semiconductor, the first auxiliary resistance is connected between the source electrode and grid of metal-oxide-semiconductor
R11 is serially connected with the 6th resistance R6 between the control terminal of master switch pipe Q and the first end of the first switch tube Q1.
It is understood that the purpose of the 6th resistance R6 and the first auxiliary resistance R11 are in order to limit the grid of master switch pipe Q
Voltage, (specific resistance value is determined by metal-oxide-semiconductor parameter and operating voltage).
In a preferred embodiment, first switch tube Q1 is triode, is connected between the base stage and emitter of first switch tube Q1
It is connected to the second auxiliary resistance R12.
It is understood that R12 improves the anti-interference ability of triode, be connected after avoiding being disturbed of triode.
In a preferred embodiment, second switch Q2 triode connects between the base stage and emitter of second switch Q2
There is third auxiliary resistance R13;The 7th resistance R7 is serially connected between second switch Q2 control terminal and the 5th resistance R5.
It is understood that R7 is the base current for limiting triode.And R13 is the input impedance for reducing transistor, is mentioned
The anti-interference ability of high transistor.
Preferably, the switching on and shutting down signal input part of key switch and control panel connects, and key switch is placed in OFF position
When send off signal to control panel, machine control signal is closed in the control panel output after predetermined time period that is delayed.
It is understood that off signal can be sent to control panel when key switch is placed in OFF position, control at this time
Plate can notify industrial personal computer to carry out software shutdown first, and after industrial personal computer soft-off is finished, control panel can just export shutdown control
Signal processed controls whole shutdown.Therefore, control panel needs the delay predetermined time period after receiving off signal to retransmit pass
Machine control signal, predetermined time period here rule of thumb need to be set greater than the time span of industrial personal computer software shutdown.
The present invention does not limit the resistance value of above each resistance and the model of each component.
The present invention also provides a kind of screening machines, including control assembly, work package, display, several scram buttons
And the power control circuit such as any of the above item;Wherein, control assembly includes control panel, industrial personal computer and sampling plate;Working group
Part includes radiographic source, Rolling motor and fan.Wherein, radiographic source here can be X source, certainly, the present invention to this not
It limits.
Preferably, control panel is connect with scram button and display respectively, and control panel is for detecting emergency stop
After button is pressed, output stop signal to display;After display receives stop signal, display scram button triggering is mentioned
Show.
It is understood that work package control circuit can power off after scram button is pressed, so that the first relay K1
Coil-end power loss, contact disconnect, power off between the work package and general supply of the first relay K1 connection, to protect work
Component.Since the work package of screening machine is powered off and can not be worked at this time, in order to enable other staff to understand current place
In the state of emergency stop power-off, misunderstanding is avoided the occurrence of, the present embodiment can show that over the display emergency stop is pressed after scram button is pressed
The prompt of button triggering facilitates staff to carry out safety check management to inform the working condition of the current screening machine of staff.
In addition, in order to protect the work package and display in screening machine, need the first relay K1 and second after
Protective tube and air switch are concatenated between electric appliance K2 and general supply, when avoiding current or voltage excessive, are burnt out aft-end assembly, are reached
To protection work package and the purpose of display safety.
Above several specific embodiments are only the preferred embodiment of the present invention, and above several specific embodiments can be with
Any combination, the embodiment obtained after combination is also within protection scope of the present invention.It should be pointed out that for the art
For those of ordinary skill, relevant speciality technical staff deduced out in the case where not departing from spirit of that invention and concept thereof other change
Into and variation, should all be included in the protection scope of the present invention.
It should also be noted that, in the present specification, relational terms such as first and second and the like be used merely to by
One entity or operation are distinguished with another entity or operation, without necessarily requiring or implying these entities or operation
Between there are any actual relationship or orders.Moreover, the terms "include", "comprise" or its any other variant meaning
Covering non-exclusive inclusion, so that the process, method, article or equipment for including a series of elements not only includes that
A little elements, but also including other elements that are not explicitly listed, or further include for this process, method, article or
The intrinsic element of equipment.In the absence of more restrictions, the element limited by sentence "including a ...", is not arranged
Except there is also other identical elements in the process, method, article or apparatus that includes the element.