CN103296937A - Control circuit and control method of direct-current motor - Google Patents
Control circuit and control method of direct-current motor Download PDFInfo
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- CN103296937A CN103296937A CN2012100411847A CN201210041184A CN103296937A CN 103296937 A CN103296937 A CN 103296937A CN 2012100411847 A CN2012100411847 A CN 2012100411847A CN 201210041184 A CN201210041184 A CN 201210041184A CN 103296937 A CN103296937 A CN 103296937A
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Abstract
The invention discloses a control circuit and a control method of a direct-current motor. The control circuit of the direct-current motor comprises a first rectification unit with an alternating-current input end connected with a power supply through a power supply line, a switch unit arranged on a firing line or a null line of the power supply line, a double-contact relay connected between a direct-current output end of the first rectification unit and the direct-current motor, a detection unit arranged on the firing line or the null line of the power supply line and used for detecting if the switch unit is closed, and a control unit connected with the switch unit, a control coil of the double-contact relay and the detection unit, and the control unit is used for controlling the double-contact relay to close when the detection unit detects that the switch unit is switched off and controlling the switch unit to close after preset time after the double-contact relay is closed. The control circuit and the control method of the direct-current motor solves the problems that in the prior art, a control circuit of a direct-current motor has potential electric safety hazards and is prone to short circuit, and therefore operation safety of the direct-current motor is improved.
Description
Technical field
The present invention relates to circuit field, in particular to a kind of control of DC circuit and control method.
Background technology
In the prior art, connect to control DC motor positive and negative rotation by using a switching device of often opening and a double-contact normally closed relay.Power supply is by behind the switching device, both positive and negative polarity connects two common port contacts of double-contact normally closed relay respectively, first group normally opened contact of one end of direct current machine and double-contact normally closed relay is connected with second group normally-closed contact, the normally opened contact of the other end of motor and second group of double-contact normally closed relay is connected with first group normally-closed contact, and concrete winding diagram as shown in Figure 1.
When the needs motor is just changeing, the control switch break-over of device, electric current provides power supply through two normally-closed contacts of relay for motor, and motor just changes.
When the needs motor reverses, the control switch break-over of device, the common port contact of relay is connected with normally opened contact by plug-in strip, the relay conducting, electric current provides power supply through two normally opened contacts of relay for motor, the motor counter-rotating.
But this kind of available technology adopting circuit carries out the control mode of DC motor positive and negative rotation, the make-and-break time of switching device and relay is not controlled, when the counter-rotating of control motor, if switching device is prior to relay closes, then relay has forceful electric power, can produce the arcing phenomenon in closed moment, there is electrical safety hidden danger, and, if two groups of contacts are not closed simultaneously during the actuating of relay, have one group of contact closed earlier, another group contact is not closed, then can be short-circuited.
Problem at there is electrical safety hidden danger in control of DC circuit in the correlation technique and is short-circuited does not easily propose effective solution at present as yet.
Summary of the invention
Main purpose of the present invention is to provide a kind of control of DC circuit and control method, to solve the problem that there is electrical safety hidden danger in the control of DC circuit and is short-circuited easily in the correlation technique.
To achieve these goals, according to an aspect of the present invention, provide a kind of control of DC circuit, having comprised: first rectification unit, wherein, the ac input end of first rectification unit is connected with power supply by supply line; Switch element is arranged on the live wire or zero line of supply line; Double-contact relay is connected between the dc output end and direct current machine of first rectification unit; Whether detecting unit is arranged on the live wire or zero line of supply line, closed for detection of switch element; And control unit, all be connected with detecting unit with the control coil of switch element, double-contact relay, be used for control double-contact relay closure when detecting unit detects switch element and disconnects, and behind the Preset Time after the double-contact relay closure control switch unit closure.
Further, the common port contact of double-contact relay is connected with the dc output end of first rectification unit.
Further, the common port contact of double-contact relay is connected with direct current machine.
Further, switch element is the single contact relay, and wherein, the control coil of single contact relay is connected with control unit.
Further, control circuit also comprises: first drive circuit is connected between the control coil and control unit of single contact relay; And second drive circuit, be connected between the control coil and control unit of double-contact relay.
Further, first drive circuit comprises: the first transistor, first resistance and second resistance, wherein, first end of the first transistor is connected with first end of first resistance, second end of first resistance is connected with control unit, second end of the first transistor is connected with the control coil of single contact relay, the 3rd end ground connection of the first transistor, first end of second resistance is connected first node, the second end ground connection of second resistance, first node is the node between first end of first end of the first transistor and first resistance, second drive circuit comprises: transistor seconds, the 3rd resistance and the 4th resistance, wherein, first end of transistor seconds is connected with first end of the 3rd resistance, second end of the 3rd resistance is connected with control unit, second end of transistor seconds is connected with the control coil of double-contact relay, the 3rd end ground connection of transistor seconds, first end of the 4th resistance is connected Section Point, the second end ground connection of the 4th resistance, Section Point are the node between first end of first end of transistor seconds and the 3rd resistance.
Further, detection means comprises current transformer, modular type Hall current sensor, light-coupled isolation amplifier, condenser type isolated amplifier or sigma delta formula isolated amplifier, detection means can also be made of the current detection circuit that detection resistance and operational amplifier are formed, utilize the detection shunt resistance to detect, as the constantan wire detection method.
Further, when detection means is current transformer, when the primary coil of current transformer is arranged on the live wire of supply line or the zero line, control circuit also comprises: second rectification unit, wherein, the ac input end of second rectification unit is connected with the secondary coil of current transformer, and the dc output end of second rectification unit is connected with control unit.
Further, control circuit also comprises: filter unit is connected between the dc output end of control unit and second rectification unit; And divider resistance, be connected between the dc output end of filter unit and second rectification unit.
To achieve these goals, according to a further aspect in the invention, provide a kind of control of DC method, this control method is carried out by the control circuit that foregoing of the present invention provides, and comprising: whether the switch element that detects control circuit is closed; And when switch element disconnects control control circuit the double-contact relay closure, and behind the Preset Time after the double-contact relay closure control switch unit closure.
Further, the double-contact relay closure of control control circuit comprises when switch element disconnects: the common port contact of control double-contact relay is connected with the normally opened contact of double-contact relay; Or the common port contact of control double-contact relay is connected with the normally-closed contact of double-contact relay.Particularly, suppose to be in when just changeing state when direct current machine, the common port contact of double-contact relay is connected with normally-closed contact, in control method of the present invention, when needs control direct current machine transfers inverted status to (perhaps by commentaries on classics state just, transferred to by starting state not and to start the back inverted status) time, the common port contact of then controlling double-contact relay when switch element disconnects is connected with normally opened contact; When needs control direct current machine transfers when just changeing state (perhaps, just changeing state by starting state not after transferring startup to) to by inverted status, the common port contact of then controlling double-contact relay when switch element disconnects is connected with normally-closed contact.
By the present invention, adopt the circuit that comprises following structure: first rectification unit, wherein, the ac input end of first rectification unit is connected with power supply by supply line; Switch element is arranged on the live wire or zero line of supply line; Double-contact relay is connected between the dc output end and direct current machine of first rectification unit; Whether detecting unit is arranged on the live wire or zero line of supply line, closed for detection of switch element; And control unit, with switch element, the control coil of double-contact relay all is connected with detecting unit, be used for control double-contact relay closure when detecting unit detects the switch element disconnection, and behind the Preset Time after the double-contact relay closure control switch unit closure, by the circuit that is connected with power supply at first rectification unit detecting unit is set, the closure that control unit can be judged switch element according to the test result of this detecting unit whether, to guarantee that control unit is after the adequate closure of control double-contact relay, control switch unit closure again, electrical safety hidden danger and short circuit have been avoided, solve the problem that there is electrical safety hidden danger in the control of DC circuit and is short-circuited easily in the prior art, and then reached the effect that improves direct current machine running fail safe.
Description of drawings
The accompanying drawing that constitutes the application's a part is used to provide further understanding of the present invention, and illustrative examples of the present invention and explanation thereof are used for explaining the present invention, do not constitute improper restriction of the present invention.In the accompanying drawings:
Fig. 1 is the schematic diagram according to the control circuit of correlation technique;
Fig. 2 is the schematic diagram according to the control circuit of first embodiment of the invention;
Fig. 3 is the schematic diagram according to the control circuit of second embodiment of the invention;
Fig. 4 is the schematic diagram according to the control circuit of first preferred embodiment of the invention;
Fig. 5 is the schematic diagram according to the control circuit of second preferred embodiment of the invention; And
Fig. 6 is the flow chart according to the control method of the embodiment of the invention.
Embodiment
Need to prove that under the situation of not conflicting, embodiment and the feature among the embodiment among the application can make up mutually.Describe the present invention below with reference to the accompanying drawings and in conjunction with the embodiments in detail.
Fig. 2 is the schematic diagram according to the control circuit of first embodiment of the invention, and as shown in Figure 2, the control circuit of first embodiment of the invention comprises switch element, first rectification unit, detecting unit, double-contact relay and control unit (not shown).
Particularly, the ac input end of first rectification unit is connected with power supply by supply line; Switch element is arranged on the live wire or zero line of supply line; The common port contact of double-contact relay is connected with the dc output end of first rectification unit, and normally opened contact is connected with direct current machine with normally-closed contact, and control coil is connected with control unit; Whether detecting unit is arranged on the live wire or zero line of supply line, closed for detection of switch element; Control unit all is connected with detecting unit with switch element.
The operation principle of the control circuit of first embodiment of the invention is: power supply is through the first rectifier power source rectification, DC power supply both positive and negative polarity after the rectification connects two common port contacts of double-contact normally closed relay respectively, first group normally opened contact of one end of direct current machine and double-contact normally closed relay is connected with second group normally-closed contact, and the normally opened contact of the other end of direct current machine and second group of double-contact normally closed relay is connected with first group normally-closed contact.Wherein, the flow process of control direct current machine running comprises as shown in Figure 6: S602, and whether the switch element that detects control circuit is closed; And S604, the double-contact relay closure of control control circuit when switch element disconnects, and behind the Preset Time after the double-contact relay closure control switch unit closure, particularly, suppose to be in when just changeing state when direct current machine, the common port contact of double-contact relay is connected with normally-closed contact, (just subcontracting and drawing together: just changeing after startup transfers startup to when the needs motor just changes, inverted status transfers to just changes state) time, control unit is controlled the double-contact normally closed relay earlier when switch element disconnects plug-in strip closes on two normally-closed contacts, then after after a while, control unit control switch unit closure, electric current provides power supply through two normally-closed contacts of double-contact normally closed relay for motor, and this moment, direct current machine just changeed; (counter-rotating comprises: counter-rotating after startup transfers startup to when the counter-rotating of needs motor, just the commentaries on classics state transfers inverted status to) time, at first whether detected by the closure of detecting unit to switch element, whether control unit can judge the switch element closure according to the output result of detecting unit, when detecting the switch element disconnection, the action of control unit control double-contact normally closed relay, again after a period of time time-delay, this section period gives double-contact normally closed relay adequate time closed fully, so that its plug-in strip closes on two normally opened contacts, afterwards, control unit control switch unit closure, electric current provides power supply through two normally opened contacts of double-contact normally closed relay for motor, direct current machine counter-rotating this moment.
Control unit in the first embodiment of the invention can be single-chip microcomputer, and wherein, the control coil of switch element, double-contact relay and detecting unit are connected respectively on 3 I/O of single-chip microcomputer.
By elder generation's sense switch unit closure when the needs motor reverses whether, when switch element disconnects, to control the double-contact relay closure, wait the double-contact relay closure after, control switch unit closure again.Effectively prevent the short circuit phenomenon that arcing phenomenon that double-contact relay that switch element causes prior to the double-contact relay closure produced in closed moment and double-contact produce when successively closed, reached the effect that improves direct current machine running fail safe.
Fig. 3 is the schematic diagram according to the control circuit of second embodiment of the invention, compare with the control circuit of first embodiment of the invention, the two difference is, the common port contact of double-contact relay is connected with direct current machine in the control circuit of second embodiment of the invention, and the operation principle of control circuit is identical with the operation principle of the control circuit of first embodiment of the invention.
The control circuit of second embodiment of the invention is except the effect of the control circuit that can reach first embodiment, can also effectively avoid as relay R LY2 because there is a contact to damage, cause a plug-in strip of double-contact relay close at first group often open (normally closed) contact, the short circuit problem that the another one plug-in strip brings when closing at normally closed (often opening) contact of second group has reached the effect that improves direct current machine running fail safe better.
Fig. 4 is the schematic diagram according to the control circuit of first preferred embodiment of the invention, as shown in Figure 4, the control circuit of first preferred embodiment of the invention is compared with the control circuit of first embodiment of the invention, the two difference is, switch element is single contact relay R LY1 in first preferred embodiment of the invention, the control coil of single contact relay R LY1 is connected with control unit, detecting unit is current transformer, and the control circuit of first preferred embodiment of the invention also comprises: first driver element, second driver element and second rectification unit.
Wherein, detecting unit can also be in modular type Hall current sensor, light-coupled isolation amplifier, condenser type isolated amplifier or the sigma delta formula isolated amplifier any one, detecting unit can also be made of the current detection circuit that detection resistance and operational amplifier are formed, utilize the detection shunt resistance to detect, as the constantan wire detection method.
Particularly, be that current transformer is illustrated with the detecting unit, the primary coil of current transformer is arranged on live wire or the zero line, secondary coil is connected with the ac input end of second rectification unit, first driver element is by the first transistor Q1, first resistance R 1 and second resistance R 2 are formed, second driver element is by transistor seconds Q2, the 3rd resistance R 3 and the 4th resistance R 4 are formed, second rectification unit is by four diodes (first diode D1, the second diode D2, the 3rd diode D3 and the 4th diode D4) rectifier bridge formed, after single contact relay R LY1 closure, current transformer produces induced current, and control unit produces electric current according to current transformer and whether whether judges single contact relay R LY1 closure.
When the needs motor is just changeing, control unit control triode Q1 conducting, relay R LY1 closure, the two normally-closed contacts by relay R LY2 after the rectification of electric current process rectifier bridge provide power supply for motor, and motor just changes.When the needs motor reverses, at first detect the current transformer output by control unit no current is arranged, be zero as electric current, be not conducting of RLY1, then by control unit control triode Q2 conducting, relay R LY2 closure, after the software set time-delay, control triode Q1 conducting by control unit again, relay R LY1 closure, the two normally opened contacts by relay R LY2 after the rectification of electric current process rectifier bridge provide power supply for motor, the motor counter-rotating.Effectively prevent the short circuit phenomenon that arcing phenomenon that relay that switch element causes prior to relay closes produced in closed moment and double-contact produce when successively closed, reached the effect that improves direct current machine running fail safe.
Fig. 5 is the schematic diagram according to the control circuit of second preferred embodiment of the invention, as shown in Figure 5, the control circuit of second preferred embodiment of the invention is compared with the control circuit of first preferred embodiment of the invention, the two difference is, in second preferred embodiment of the invention, the common port contact of double-contact relay is connected with direct current machine, and the control circuit of second preferred embodiment of the invention also comprises: filter unit and divider resistance R5.
Particularly, filter unit is made of resistance R 6 and capacitor C parallel connection, is connected with the dc output end of second rectification unit by divider resistance R5.The operation principle of the control circuit control DC motor positive and negative rotation of second preferred embodiment of the invention is identical with the control principle of first preferred embodiment of the invention.By increasing divider resistance R5, with the voltage that guarantees to enter single-chip microcomputer in the operating voltage range of single-chip microcomputer, in case overtension burns out single-chip microcomputer; Filter circuit can the filtering rectification circuit in ripple in the output voltage, the output voltage ripple coefficient is reduced, it is smoother that waveform becomes.
The control circuit of second preferred embodiment of the invention is except the effect of the control circuit that can reach first preferred embodiment, can also effectively avoid as relay R LY2 because there is a contact to damage, cause a plug-in strip of double-contact relay close at first group often open (normally closed) contact, the short circuit problem that the another one plug-in strip brings when closing at normally closed (often opening) contact of second group has reached the effect that improves direct current machine running fail safe better.
The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (12)
1. a control of DC circuit is characterized in that, comprising:
First rectification unit, wherein, the ac input end of described first rectification unit is connected with power supply by supply line;
Switch element is arranged on the live wire or zero line of described supply line;
Double-contact relay is connected between the dc output end and direct current machine of described first rectification unit;
Whether detecting unit is arranged on the live wire or zero line of described supply line, closed for detection of described switch element; And
Control unit, all be connected with described detecting unit with the control coil of described switch element, described double-contact relay, control described double-contact relay closure for detecting at described detecting unit when described switch element disconnects, and behind the Preset Time after the described double-contact relay closure, control described switch element closure.
2. control circuit according to claim 1 is characterized in that, the common port contact of described double-contact relay is connected with the dc output end of described first rectification unit.
3. control circuit according to claim 1 is characterized in that, the common port contact of described double-contact relay is connected with described direct current machine.
4. according to claim 2 or 3 described control circuits, it is characterized in that described switch element is the single contact relay, wherein, the control coil of described single contact relay is connected with described control unit.
5. control circuit according to claim 4 is characterized in that, described control circuit also comprises:
First drive circuit is connected between the control coil and described control unit of described single contact relay; And
Second drive circuit is connected between the control coil and described control unit of described double-contact relay.
6. control circuit according to claim 5 is characterized in that,
Described first drive circuit comprises: the first transistor (Q1), first resistance (R1) and second resistance (R2), wherein, first end of described the first transistor (Q1) is connected with first end of described first resistance (R1), second end of described first resistance (R1) is connected with described control unit, second end of described the first transistor (Q1) is connected with the control coil of described single contact relay, the 3rd end ground connection of described the first transistor (Q1), first end of described second resistance (R2) is connected first node, the second end ground connection of described second resistance (R2), described first node is the node between first end of first end of described the first transistor (Q1) and described first resistance (R1)
Described second drive circuit comprises: transistor seconds (Q2), the 3rd resistance (R3) and the 4th resistance (R4), wherein, first end of described transistor seconds (Q2) is connected with first end of described the 3rd resistance (R3), second end of described the 3rd resistance (R3) is connected with described control unit, second end of described transistor seconds (Q2) is connected with the control coil of described double-contact relay, the 3rd end ground connection of described transistor seconds (Q2), first end of described the 4th resistance (R4) is connected Section Point, the second end ground connection of described the 4th resistance (R4), described Section Point are the node between first end of first end of described transistor seconds (Q2) and described the 3rd resistance (R3).
7. control circuit according to claim 1 is characterized in that, described detecting unit comprises: current transformer, the primary coil of described current transformer are arranged on the live wire or zero line of described supply line.
8. control circuit according to claim 7, it is characterized in that, described detecting unit also comprises: second rectification unit, wherein, the ac input end of described second rectification unit is connected with the secondary coil of described current transformer, and the dc output end of described second rectification unit is connected with described control unit.
9. control circuit according to claim 8 is characterized in that, described control circuit also comprises: filter unit is connected between the dc output end of described control unit and described second rectification unit; And
Divider resistance is connected between the dc output end of described filter unit and described second rectification unit.
10. control circuit according to claim 8 is characterized in that, described second rectification unit comprises:
First diode (D1), negative electrode is connected with described controller;
Second diode (D2), negative electrode is connected with described controller;
The 3rd diode (D3), plus earth connects; And
The 4th diode (D4), plus earth connects,
Wherein, described first diode (D1) is connected with described the 3rd diode (D3), described second diode (D2) and described the 4th diode (D4) series connection, first output of described current transformer and second output are connected to the 3rd node and the 4th node, wherein, described the 3rd node is the node between described first diode (D1) and described the 3rd diode (D3), and described the 4th node is the node between described second diode (D2) and described the 4th diode (D4).
11. a control of DC method is characterized in that, adopts each described control circuit control direct current machine running in the claim 1 to 10, described method comprises:
Whether the switch element that detects described control circuit is closed; And
When described switch element disconnects, control the double-contact relay closure of described control circuit, and behind the Preset Time after the described double-contact relay closure, control described switch element closure.
12. the control method according to claim 11 is characterized in that, the double-contact relay closure of controlling described control circuit when described switch element disconnects comprises:
The common port contact of controlling described double-contact relay is connected with the normally opened contact of described double-contact relay; Or
The common port contact of controlling described double-contact relay is connected with the normally-closed contact of described double-contact relay.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012100411847A CN103296937A (en) | 2012-02-22 | 2012-02-22 | Control circuit and control method of direct-current motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012100411847A CN103296937A (en) | 2012-02-22 | 2012-02-22 | Control circuit and control method of direct-current motor |
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| CN103296937A true CN103296937A (en) | 2013-09-11 |
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| CN2012100411847A Pending CN103296937A (en) | 2012-02-22 | 2012-02-22 | Control circuit and control method of direct-current motor |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN107631418A (en) * | 2017-08-22 | 2018-01-26 | 珠海格力电器股份有限公司 | Switching method, device and the air-conditioning equipment of windscreen |
| CN108172098A (en) * | 2016-12-07 | 2018-06-15 | 北京市昌平区平西府中心小学 | Student's jade carving machine |
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Application publication date: 20130911 |