CN212305141U - PLC power front end EMC protection circuit and PLC power - Google Patents
PLC power front end EMC protection circuit and PLC power Download PDFInfo
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- CN212305141U CN212305141U CN202021781992.3U CN202021781992U CN212305141U CN 212305141 U CN212305141 U CN 212305141U CN 202021781992 U CN202021781992 U CN 202021781992U CN 212305141 U CN212305141 U CN 212305141U
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Abstract
The embodiment of the utility model discloses PLC power front end EMC protection circuit and PLC power. This PLC power front end EMC protection circuit includes surge clamper protection module, common mode filtering module, differential mode filtering module and voltage stabilizing module, surge clamper protection module is connected with the power input end electricity, surge clamper protection module is used for the protection power not disturbed by the surge, common mode filtering module is connected with surge clamper protection module and differential mode filtering module electricity, common mode filtering module is used for absorbing electric fast transient pulse voltage and electrostatic discharge voltage, differential mode filtering module is used for reducing the literal wave of power, voltage stabilizing module is connected with differential mode filtering module electricity, voltage stabilizing module is used for stabilizing the voltage of power output, the embodiment of the utility model provides a technical scheme has solved current PLC controller in complicated industrial environment, easily receives electromagnetic interference's problem, improves the anti-electromagnetic interference ability of PLC power.
Description
Technical Field
The embodiment of the utility model provides a relate to circuit technical field, especially relate to a PLC power front end EMC protection circuit and PLC power.
Background
Aiming at the problems that a PLC is used in a complex industrial environment, a large amount of electromagnetic interference exists in a PLC system environment, interference sources comprise surge voltage, power supply pulse, static electricity, surge interference, radiation interference and the like generated by a high-power electric appliance, and the stability of a PLC power supply is influenced.
The problem that the existing PLC is easy to suffer from electromagnetic interference in a complex industrial environment becomes a problem to be solved urgently in the industry.
SUMMERY OF THE UTILITY MODEL
An embodiment of the utility model provides a PLC power front end EMC protection circuit and PLC power to solve current PLC controller in complicated industrial environment, easily receive electromagnetic interference's problem, improve the electromagnetic Compatibility (EMC, Electro Magnetic Compatibility) of PLC power.
In order to realize the technical problem, the utility model discloses a following technical scheme:
in a first aspect, the embodiment of the utility model provides a PLC power front end EMC protection circuit, include:
the device comprises a surge clamping protection module, a common mode filtering module, a differential mode filtering module and a voltage stabilizing module;
the surge clamping protection module is electrically connected with the input end of the power supply and is used for protecting the power supply from surge interference;
the common-mode filtering module is electrically connected with the surge clamping protection module and the differential-mode filtering module and is used for absorbing electric fast transient pulse voltage and electrostatic discharge voltage; the differential mode filtering module is used for reducing the text wave of the power supply;
the voltage stabilizing module is electrically connected with the differential mode filtering module and is used for stabilizing the voltage output by the power supply.
Further, the surge clamping protection module comprises a first diode and a piezoresistor;
the positive pole of first diode is connected with the first end of piezo-resistor and surge clamp protection module's positive input end and anodal output electricity, and the negative pole of first diode is connected with the second end of piezo-resistor and surge clamp protection module's negative input end and negative output electricity.
Further, the common mode filtering module comprises a first inductor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a sixth capacitor;
the first end of the first inductor is electrically connected with the positive input end of the common-mode filtering module, the second end of the first inductor is electrically connected with the negative input end of the common-mode filtering module, the third end of the first inductor is electrically connected with the positive output end of the common-mode filtering module, and the fourth end of the first inductor is electrically connected with the negative output end of the common-mode filtering module;
the first end of the first inductor is electrically connected with the second end of the first inductor through a first capacitor, the first end of the first inductor is grounded through a fourth capacitor, and the second end of the first inductor is grounded through a third capacitor;
the third end of the first inductor is electrically connected with the fourth end of the first inductor through a second capacitor, the third end of the first inductor is grounded through a sixth capacitor, and the fourth end of the first inductor is grounded through a fifth capacitor.
Further, the differential mode filtering module comprises a second inductor, a second capacitor, a seventh capacitor and an eighth capacitor;
the first end of the second inductor is electrically connected with the first end of the second capacitor and the positive input end of the differential mode filtering module, and the second end of the second inductor is electrically connected with the first end of the seventh capacitor, the first end of the eighth capacitor and the output end of the differential mode filtering module; the second end of the second capacitor, the second end of the seventh capacitor and the second end of the eighth capacitor are grounded.
Further, the voltage stabilizing module comprises a first switch tube, a second switch tube, a third switch tube, a first resistor, a second resistor, a third resistor and a fourth resistor;
the first end of the first switching tube is electrically connected with the first end of the second switching tube, the first end of the third resistor and the input end of the voltage stabilizing module; the second end of the first switching tube is electrically connected with the first end of the first resistor and the output end of the voltage stabilizing module;
the control end of the first switch tube is electrically connected with the second end of the second switch tube; the control end of the second switching tube is electrically connected with the second end of the third resistor and the first end of the fourth resistor;
the second end of the fourth resistor is electrically connected with the first end of the third switching tube, the second end of the third switching tube is grounded, the control end of the third switching tube is electrically connected with the second end of the first resistor and the first end of the second resistor, and the second end of the second resistor is grounded.
Further, the EMC protection circuit further includes: an anti-reverse module;
the surge clamping protection module is electrically connected with the power input end through the reverse connection prevention module, and the reverse connection prevention module is used for reducing the voltage drop of the power supply and preventing the positive electrode and the negative electrode of the power supply from being reversely connected.
Further, the reverse connection prevention module comprises a fourth switch tube, a fifth switch tube and a fifth resistor;
the first end of the fifth resistor is electrically connected with the positive input end of the power supply and the positive output end of the reverse connection prevention module, and the second end of the fifth resistor is electrically connected with the control end of the fourth switching tube and the control end of the fifth switching tube;
the first end of the fourth switching tube is electrically connected with the negative electrode input end of the power supply, the second end of the fourth switching tube is electrically connected with the first end of the fifth switching tube, and the second end of the fifth switching tube is electrically connected with the negative electrode output end of the reverse connection preventing module.
Further, the EMC protection circuit further includes:
and the soft-off protection module is electrically connected with the voltage stabilizing module and is used for carrying out software shutdown on the power supply.
Further, the soft-off protection module comprises a sixth switching tube, a second diode, a third diode, a sixth resistor, a seventh resistor, an eighth resistor and a ninth resistor;
a first end of a sixth switching tube is electrically connected with a first end of the ninth resistor, a second end of the ninth resistor is electrically connected with a first end of the eighth resistor and a control end of the first switching tube, a second end of the eighth resistor is electrically connected with an input end of the voltage stabilizing module, and a second end of the sixth switching tube is grounded; the control end of the sixth switching tube is electrically connected with the cathode of the second diode and the cathode of the third diode, the anode of the second diode is electrically connected with the system hardware switch through a sixth resistor, and the anode of the third diode is electrically connected with the system soft switch through a seventh resistor.
In a second aspect, the embodiment of the present invention further provides a PLC power supply, including the first aspect arbitrary PLC power supply front end EMC protection circuit.
The utility model provides a PLC power front end EMC protection circuit, including surge clamp protection module, common mode filter module, differential mode filter module and voltage stabilizing module, surge clamp protection module is connected with the power input end electricity, surge clamp protection module is used for protecting the power from surge interference, common mode filter module is connected with surge clamp protection module and differential mode filter module electricity, common mode filter module is used for absorbing electric fast transient pulse voltage and electrostatic discharge voltage, differential mode filter module is used for reducing the text wave of power, voltage stabilizing module is connected with differential mode filter module electricity, voltage stabilizing module is used for stabilizing the voltage of power output, protect the power from surge interference through surge clamp module, absorb electric fast transient pulse voltage and electrostatic discharge voltage through common mode filter module, the text wave of power is reduced through differential mode filter module, and the voltage of power output is stabilized through voltage stabilizing module, the problem that the existing PLC is easily subjected to electromagnetic interference in a complex industrial environment is solved, and the anti-electromagnetic interference capability of a PLC power supply is improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly described below, and 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 the contents of the embodiments of the present invention and the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an EMC protection circuit at the front end of a PLC power supply provided in an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another PLC power supply front end EMC protection circuit provided in the embodiment of the present invention;
fig. 3 is a schematic structural diagram of an EMC protection circuit of a PLC power supply front end according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of an EMC protection circuit of a PLC power supply front end according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of an EMC protection circuit of a PLC power supply front end according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of an EMC protection circuit of a PLC power supply front end according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of an EMC protection circuit of a PLC power supply front end according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of an EMC protection circuit of a PLC power supply front end according to an embodiment of the present invention;
fig. 9 is a schematic structural diagram of an EMC protection circuit of a PLC power supply front end according to an embodiment of the present invention;
fig. 10 is a schematic structural diagram of a PLC power supply according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Fig. 1 is the embodiment of the utility model provides a PLC power front end EMC protection circuit's structural schematic. Referring to fig. 1, the PLC power front end EMC protection circuit 8 provided in the embodiment of the present invention includes a surge clamp protection module 1, a common mode filter module 2, a differential mode filter module 3, and a voltage stabilization module 4, where the surge clamp protection module 1 is electrically connected to a power input terminal 10, the surge clamp protection module 1 is used to protect a power supply from surge interference, the common mode filter module 2 is electrically connected to the surge clamp protection module 1 and the differential mode filter module 3, and the common mode filter module 2 is used to absorb electric fast transient pulse voltage and electrostatic discharge voltage; the differential mode filtering module 3 is used for reducing the text wave of the power supply, the voltage stabilizing module 4 is electrically connected with the differential mode filtering module 3, and the voltage stabilizing module 4 is used for stabilizing the voltage output by the power supply.
Specifically, power signal passes through power input 10 through surge clamping protection module 1, reduce the interference of surge to power signal, power signal passes through common mode filter module 2 again, common mode filter module 2 can absorb electric fast transient pulse voltage and electrostatic discharge voltage in the power signal, power signal passes through differential mode filter module 3, can reduce power signal's literal wave, and through voltage stabilizing module 4, carry out stable output to power signal, realize PLC power front end power signal's EMC protection, the anti-electromagnetic interference ability of PLC power has been improved.
The PLC power front end EMC protection circuit that this embodiment provided does not receive surge interference through surge clamping protection module protection power, absorbs electric fast transient pulse voltage and electrostatic discharge voltage through common mode filter module, reduces the Wen wave of power through differential mode filter module to stabilize the voltage of power output through voltage stabilizing module, solved current PLC controller in complicated industrial environment, easily received electromagnetic interference's problem, improve the anti-electromagnetic interference ability of PLC power.
Optionally, fig. 2 is a schematic structural diagram of another PLC power front end EMC protection circuit provided by an embodiment of the present invention. On the basis of the above embodiment, referring to fig. 2, the surge clamp protection module 1 includes a first diode 11 and a varistor 12; an anode of the first diode 11 is electrically connected to a first end of the varistor 12 and a positive input terminal 13 and a positive output terminal 14 of the surge clamp protection module 1, and a cathode of the first diode 11 is electrically connected to a second end of the varistor 12 and a negative input terminal 15 and a negative output terminal 16 of the surge clamp protection module 1.
Specifically, the first diode 11 may be a zener diode, and the first diode 11 plays a role of voltage stabilization. The voltage dependent resistor 12 performs a primary clamping function on the surge voltage inputted from the outside, and can absorb the energy of the surge voltage.
Optionally, fig. 3 is a schematic structural diagram of another PLC power front end EMC protection circuit provided by an embodiment of the present invention. On the basis of the above embodiment, referring to fig. 3, the common mode filter module 2 includes a first inductor 21, a first capacitor 22, a second capacitor 23, a third capacitor 24, a fourth capacitor 25, a fifth capacitor 26, and a sixth capacitor 27; the first end 211 of the first inductor 21 is electrically connected to the positive input end 28 of the common-mode filter module 2, the second end 212 of the first inductor 21 is electrically connected to the negative input end 29 of the common-mode filter module 2, the third end 213 of the first inductor 21 is electrically connected to the positive output end 20 of the common-mode filter module 2, and the fourth end 214 of the first inductor 21 is electrically connected to the negative output end 200 of the common-mode filter module 2; the first end 211 of the first inductor 21 is electrically connected to the second end 212 of the first inductor 21 through the first capacitor 22, the first end 211 of the first inductor 21 is grounded through the fourth capacitor 25, and the second end 212 of the first inductor 21 is grounded through the third capacitor 24; the third terminal 213 of the first inductor 21 is electrically connected to the fourth terminal 214 of the first inductor 21 through the second capacitor 23, the third terminal 213 of the first inductor 21 is grounded through the sixth capacitor 27, and the fourth terminal 214 of the first inductor 21 is grounded through the fifth capacitor 26.
Specifically, the first inductor 21 may absorb interference energy, the first capacitor 22 and the second capacitor 23 may perform a filtering function, and the third capacitor 24, the fourth capacitor 25, the fifth capacitor 26, and the sixth capacitor 27 provide an energy discharge path, which may discharge interference to the ground, so as to facilitate suppression of conducted interference and radiated interference.
Optionally, fig. 4 is a schematic structural diagram of another PLC power front end EMC protection circuit provided in the embodiment of the present invention. On the basis of the above embodiment, referring to fig. 4, the differential mode filtering module 3 includes a second inductor 31, a second capacitor 23, a seventh capacitor 32, and an eighth capacitor 33; the first end 311 of the second inductor 31 is electrically connected to the first end 231 of the second capacitor 23 and the positive input end 34 of the differential mode filter module 3, and the second end 312 of the second inductor 31 is electrically connected to the first end 321 of the seventh capacitor 32, the first end 331 of the eighth capacitor 33 and the output end 35 of the differential mode filter module 3; the second terminal 232 of the second capacitor 23, the second terminal 322 of the seventh capacitor 32 and the second terminal 332 of the eighth capacitor 33 are grounded.
Specifically, the second inductor 31, the second capacitor 23, the seventh capacitor 32 and the eighth capacitor 33 form a differential mode pi-type filter circuit, which is beneficial to reducing the ripple of the power supply signal.
Optionally, fig. 5 is a schematic structural diagram of another PLC power front end EMC protection circuit provided in the embodiment of the present invention. On the basis of the above embodiment, referring to fig. 5, the voltage stabilizing module 4 includes a first switching tube 41, a second switching tube 42, a third switching tube 43, a first resistor 44, a second resistor 45, a third resistor 46, and a fourth resistor 47; the first end 411 of the first switching tube 41 is electrically connected to the first end 421 of the second switching tube 42, the first end 461 of the third resistor 46, and the input end 48 of the voltage stabilizing module 4; the second end 412 of the first switch tube 41 is electrically connected to the first end 441 of the first resistor 44 and the output end 49 of the voltage stabilizing module 4; the control end 413 of the first switch tube 41 is electrically connected with the second end 422 of the second switch tube 42; the control terminal 423 of the second switch tube 42 is electrically connected to the second terminal 462 of the third resistor 46 and the first terminal 471 of the fourth resistor 47; the second terminal 472 of the fourth resistor 47 is electrically connected to the first terminal 431 of the third switching tube 43, the second terminal 432 of the third switching tube 43 is grounded, the control terminal 433 of the third switching tube 43 is electrically connected to the second terminal 442 of the first resistor 44 and the first terminal 451 of the second resistor 45, and the second terminal 452 of the second resistor 45 is grounded.
Specifically, the first resistor 44 and the second resistor 45 are used for setting a specific regulated voltage value of the EMC protection circuit at the front end of the PLC power supply, and when the voltage of the power supply signal is lower than a set value, the power supply voltage regulation function is not triggered, and the power supply signal is directly output; when the voltage of the power signal is higher than the set value, the third switching tube 43 is turned on, the third resistor 46 and the fourth resistor 47 perform a voltage division function, the second switching tube 42 is turned on, so that the first switching tube 41 is turned off, and at this time, the voltage stabilizing module 4 does not output the power signal; the first resistor 44 and the second resistor 45 have no current passing through, the third switch tube 43 is turned off, the third resistor 46 and the fourth resistor 47 have no current passing through, and the second switch tube 42 is turned off, so that the first switch tube 41 is turned on, and the voltage stabilizing module 4 outputs a power supply signal.
For example, the first switch tube 41 may be a P-MOS tube, the second switch tube 42 may be a PNP transistor, and the third switch tube 43 may be an NPN transistor. When the voltage of the power supply signal is lower than a set value, the power supply voltage stabilization function is not triggered, and the power supply signal is directly output; when the voltage of the power signal is higher than the set value, the voltage Vb at the control terminal 433 of the third switching tube 43, i.e., the base, is higher than the voltage Ve at the second terminal 432 of the third switching tube 43, i.e., the emitter, the third switching tube 43 is turned on, so that the third resistor 46 and the fourth resistor 47 perform voltage division, the voltage Vb at the control terminal 423 of the second switching tube 42, i.e., the base, is lower than the voltage Ve at the second terminal 422 of the second switching tube 42, i.e., the emitter, the second switching tube 42 is turned on, so that the control terminal 413 of the first switching tube 41, i.e., the gate G, is shorted with the first terminal 411, i.e., the drain D, of the first switching tube 41, and the voltage V between the control terminal 413 of the first switching tube 41, i.e., the gate GGS<2.5V, the first switch tube 41 is turned off, at this time, the voltage stabilizing module 4 does not output the power supply signal, at this time, the divided voltage of the first resistor 44 and the second resistor 45 is reduced to be insufficient to open the third switch tube 43, so that the third switch tube 43 is turned off, the voltage Vb of the control terminal 423, i.e., the base, of the second switch tube 42 is not less than the voltage Ve of the second terminal 422, i.e., the emitter, of the second switch tube 42, the second switch tube 42 is turned off, the level of the control terminal 413, i.e., the gate G, of the first switch tube 41 is changed to the low level, the control terminal 413, i.e., the gate G, of the first switch tube 41 is disconnected from the first terminal 411, i.e., the drain D, the second terminal 412, i.e., the source, of the first switch tube 41 is connected to.
Optionally, with continued reference to fig. 5, the voltage stabilizing module 4 may further include a tenth capacitor 40 and an eleventh capacitor 400, a first end of the tenth capacitor 40 and a first end of the eleventh capacitor 400 are electrically connected to the output end 49 of the voltage stabilizing module 4, a second end of the tenth capacitor 40 and a second end of the eleventh capacitor 400 are grounded, and the output voltage signal is filtered to obtain the set stabilized voltage value.
Optionally, with continued reference to fig. 5, the voltage stabilizing module 4 may further include a twelfth capacitor 402 and a voltage stabilizing diode 401, where the twelfth capacitor is connected between the first end 411 and the control end 413 of the first switch tube 41, and is used for filtering the power signal. The anode of the zener diode 401 is electrically connected to the second end 422 of the second switching tube 42, the cathode of the zener diode 401 is electrically connected to the first end 421 of the second switching tube 42, and the zener diode 401 functions to stabilize voltage.
Optionally, fig. 6 is a schematic structural diagram of another PLC power front end EMC protection circuit provided in the embodiment of the present invention. On the basis of the above embodiment, referring to fig. 6, the PLC power front end EMC protection circuit 8 further includes an anti-reverse module 5, the surge clamp protection module 1 is electrically connected to the power input terminal 10 through the anti-reverse module 5, and the anti-reverse module 5 is used for reducing the voltage drop of the power supply and preventing the positive electrode and the negative electrode of the power supply from being reversely connected.
Specifically, the arrangement enables the power supply signal to enter the surge clamping protection module 1 through the reverse connection prevention module 5, so that the voltage drop of the power supply signal is reduced while the positive electrode and the negative electrode of the power supply are prevented from being reversely connected, and the power loss of the power supply is reduced.
Optionally, fig. 7 is a schematic structural diagram of another PLC power front end EMC protection circuit provided in the embodiment of the present invention. On the basis of the above embodiment, referring to fig. 7, the reverse connection preventing module 5 includes a fourth switch tube 51, a fifth switch tube 52 and a fifth resistor 53; a first end 531 of the fifth resistor 53 is electrically connected to the positive input end 101 of the power input end 10 and the positive output end 54 of the reverse-connection prevention module 5, and a second end 532 of the fifth resistor 53 is electrically connected to the control end 513 of the fourth switching tube 51 and the control end 523 of the fifth switching tube 52; the first end 511 of the fourth switching tube 51 is electrically connected to the negative input end 102 of the power input end 10, the second end 522 of the fourth switching tube 51 is electrically connected to the first end 521 of the fifth switching tube 52, and the second end 522 of the fifth switching tube 52 is electrically connected to the negative output end 55 of the anti-reverse connection module 5.
Specifically, the fourth switching tube 51 and the fifth switching tube 52 may be N-MOS tubes. When the first terminal of the fifth resistor 53 is connected to the powerWhen the positive input terminal 101 of the source is electrically connected, the fifth resistor 53 divides the voltage so that the voltage V between the control terminal 513 of the fourth switching transistor 51, i.e. the gate G, and the second terminal 512 of the fourth switching transistor 51, i.e. the source SGS>0, the fourth switching tube 51 is turned on, and the voltage V between the control terminal 523 of the fifth switching tube 52, i.e. the gate G, and the first terminal 521 of the fifth switching tube 52, i.e. the source SGS>0, the fifth switching tube 52 is conducted, and the negative input end 102 of the power supply is electrically connected with the surge clamping protection module 1; if the first terminal 531 of the fifth resistor 53 is electrically connected to the negative input terminal 102 of the power supply, the voltage at the second terminal 532 of the fifth resistor 53 is at a low level, so that the voltage V between the control terminal 513 of the fourth switch tube 51, i.e. the gate, and the second terminal 512 of the fourth switch tube 51, i.e. the source S, is set to be at the low levelGS<0, the fourth switching tube 51 is turned off, and the voltage V between the control terminal 523 of the fifth switching tube 52, i.e. the gate G, and the first terminal 521 of the fifth switching tube 52, i.e. the source SGS<0, the fifth switching tube 52 is cut off, and the voltage signal input by the positive input end 101 of the power supply cannot be input to the surge clamping protection module 1, so that the situation that the positive and negative power supplies are connected with a reverse burning circuit is avoided, and meanwhile, compared with the mode of connecting a diode reversely, the voltage drop of the power supply voltage is reduced, and the power consumption is reduced.
Optionally, the reverse connection prevention module 5 may include a self-recovery fuse 56, the self-recovery fuse 56 is connected between the positive input terminal 101 of the power input terminal 10 and the positive output terminal 54 of the reverse connection prevention module 5, and the self-recovery fuse 56 is configured to activate when the current exceeds the limit current value, so as to perform overcurrent protection on the PLC power supply front end EMC protection circuit.
Optionally, fig. 8 is a schematic structural diagram of another PLC power front end EMC protection circuit provided in the embodiment of the present invention. On the basis of the above embodiment, referring to fig. 8, the PLC power front end EMC protection circuit 8 further includes a soft-off protection module 6, the soft-off protection module 6 is electrically connected to the voltage stabilizing module 4, and the soft-off protection module 6 is configured to perform software shutdown on the power supply.
Specifically, the software can be set to close the power supply, so that the hard switch is prevented from being suddenly powered off, and the system data loss fault and the malfunction fault are reduced.
Optionally, fig. 9 is a schematic structural diagram of another PLC power front end EMC protection circuit provided in the embodiment of the present invention. On the basis of the above embodiment, referring to fig. 9, the soft-off protection module 6 includes a sixth switching tube 61, a second diode 62, a third diode 63, a sixth resistor 64, a seventh resistor 65, an eighth resistor 66, and a ninth resistor 67; the first end 611 of the sixth switching tube 61 is electrically connected to the first end 671 of the ninth resistor 67, the second end 672 of the ninth resistor 67 is electrically connected to the first end 661 of the eighth resistor 66 and the control end 413 of the first switching tube 41, the second end 662 of the eighth resistor 66 is electrically connected to the input end 48 of the regulator module 4, and the second end 612 of the sixth switching tube 61 is grounded; the control terminal 613 of the sixth switching tube 61 is electrically connected to the cathode of the second diode 62 and the cathode of the third diode 63, the anode of the second diode 62 is electrically connected to the system hardware switch 68 through the sixth resistor 64, and the anode of the third diode 63 is electrically connected to the system soft switch 69 through the seventh resistor 65.
Specifically, with reference to fig. 9, the sixth switch tube 61 may be a triode, the system hardware switch 68 may be a high level or a low level, and the system hardware switch 68 may be set to be a high level when being turned on, and the system hardware switch 68 is set to be a low level when being turned off, for example, the sixth switch tube 61 may be an NPN type triode, the system hardware switch 68 is set to be a high level when being turned on, and the system soft switch 69 is set to be a high level when being turned on. When the system hardware switch 68 is turned on, a high level signal of the system hardware switch 68 passes through the sixth resistor 64 and the second diode 62, so that the sixth switching tube 61 is turned on, and at this time, the eighth resistor 66 and the ninth resistor 67 divide the voltage of the power supply signal, so that the voltage of the control end 413, i.e., the gate G, of the first switching tube 41 is lower than the voltage of the first end 411, i.e., the drain D, of the first switching tube 41, the level of the gate G of the first switching tube 41 becomes a low level, the gate G of the first switching tube 41 is disconnected from the drain D of the first switching tube 41, the second end 412, i.e., the source S and the drain D, of the first switching tube 41 are turned on, the voltage stabilizing module 4 outputs the power supply signal, and the connection terminal 100 outputs the power supply signal to the; when the system hardware switch 68 is turned off, a low level signal of the system hardware switch 68 passes through the sixth resistor 64 and the second diode 62, so that the sixth switching tube 61 is turned off, the system soft switch 69 is set to turn on the system soft switch 69, when the system soft switch 69 is triggered, the high level signal of the system soft switch 69 passes through the seventh resistor 65 and the third diode 63, so that the sixth switching tube 61 is turned on, the second end 412, i.e., the source S, of the first switching tube 41 is turned on with the first end 411, i.e., the drain D, of the first switching tube 41, and the voltage stabilizing module 4 outputs a power supply signal, so that the system hardware switch 68 can be prevented from being triggered due to sudden power failure of the system hardware switch 68, and system data loss faults and malfunction faults can be reduced.
Optionally, with continued reference to fig. 9, the soft-off protection module 6 may include a ninth capacitor 60, the ninth capacitor 60 is connected between the control terminal 613 of the sixth switching tube 61 and the second terminal 612 of the sixth switching tube 61, and the ninth capacitor 60 performs a filtering function.
Fig. 10 is a schematic structural diagram of a PLC power supply according to an embodiment of the present invention. On the basis of above-mentioned embodiment, see fig. 10, the embodiment of the utility model provides a PLC power 7 that still provides, including above-mentioned arbitrary embodiment PLC power front end EMC protection circuit 8, have above-mentioned arbitrary embodiment PLC power front end EMC protection circuit 8's beneficial effect, no longer describe herein.
It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.
Claims (10)
1. A PLC power supply front end EMC protection circuit characterized by comprising:
the device comprises a surge clamping protection module, a common mode filtering module, a differential mode filtering module and a voltage stabilizing module;
the surge clamping protection module is electrically connected with the input end of the power supply and is used for protecting the power supply from surge interference;
the common-mode filtering module is electrically connected with the surge clamping protection module and the differential-mode filtering module and is used for absorbing electric fast transient pulse voltage and electrostatic discharge voltage; the differential mode filtering module is used for reducing the text wave of the power supply;
the voltage stabilizing module is electrically connected with the differential mode filtering module and is used for stabilizing the voltage output by the power supply.
2. The EMC protection circuit of claim 1, wherein the surge clamp protection module includes a first diode and a varistor;
the anode of the first diode is electrically connected with the first end of the piezoresistor and the anode input end and the anode output end of the surge clamping protection module, and the cathode of the first diode is electrically connected with the second end of the piezoresistor and the cathode input end and the cathode output end of the surge clamping protection module.
3. The EMC protection circuit of claim 1,
the common mode filtering module comprises a first inductor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a sixth capacitor;
a first end of a first inductor is electrically connected with a positive input end of the common mode filtering module, a second end of the first inductor is electrically connected with a negative input end of the common mode filtering module, a third end of the first inductor is electrically connected with a positive output end of the common mode filtering module, and a fourth end of the first inductor is electrically connected with a negative output end of the common mode filtering module;
the first end of the first inductor is electrically connected with the second end of the first inductor through the first capacitor, the first end of the first inductor is grounded through the fourth capacitor, and the second end of the first inductor is grounded through the third capacitor;
the third end of the first inductor is electrically connected with the fourth end of the first inductor through the second capacitor, the third end of the first inductor is grounded through the sixth capacitor, and the fourth end of the first inductor is grounded through the fifth capacitor.
4. The EMC protection circuit of claim 1,
the differential mode filtering module comprises a second inductor, a second capacitor, a seventh capacitor and an eighth capacitor;
a first end of the second inductor is electrically connected with a first end of the second capacitor and a positive input end of the differential mode filtering module, and a second end of the second inductor is electrically connected with a first end of the seventh capacitor, a first end of the eighth capacitor and an output end of the differential mode filtering module; a second terminal of the second capacitor, a second terminal of the seventh capacitor, and a second terminal of the eighth capacitor are grounded.
5. The EMC protection circuit of claim 1,
the voltage stabilizing module comprises a first switching tube, a second switching tube, a third switching tube, a first resistor, a second resistor, a third resistor and a fourth resistor;
the first end of the first switching tube is electrically connected with the first end of the second switching tube, the first end of the third resistor and the input end of the voltage stabilizing module; the second end of the first switching tube is electrically connected with the first end of the first resistor and the output end of the voltage stabilizing module;
the control end of the first switch tube is electrically connected with the second end of the second switch tube; the control end of the second switch tube is electrically connected with the second end of the third resistor and the first end of the fourth resistor;
the second end of the fourth resistor is electrically connected with the first end of the third switching tube, the second end of the third switching tube is grounded, the control end of the third switching tube is electrically connected with the second end of the first resistor and the first end of the second resistor, and the second end of the second resistor is grounded.
6. The EMC protection circuit of claim 1, further comprising: an anti-reverse module;
the surge clamping protection module is electrically connected with the input end of the power supply through the reverse connection prevention module, and the reverse connection prevention module is used for reducing the voltage drop of the power supply and preventing the positive electrode and the negative electrode of the power supply from being reversely connected.
7. The EMC protection circuit of claim 6,
the reverse connection preventing module comprises a fourth switching tube, a fifth switching tube and a fifth resistor;
a first end of the fifth resistor is electrically connected with a positive input end of the power supply and a positive output end of the reverse connection prevention module, and a second end of the fifth resistor is electrically connected with a control end of the fourth switching tube and a control end of the fifth switching tube;
the first end of the fourth switch tube is electrically connected with the negative input end of the power supply, the second end of the fourth switch tube is electrically connected with the first end of the fifth switch tube, and the second end of the fifth switch tube is electrically connected with the negative output end of the reverse connection prevention module.
8. The EMC protection circuit of claim 5, further comprising: and the soft-off protection module is electrically connected with the voltage stabilizing module and is used for carrying out software shutdown on the power supply.
9. The EMC protection circuit of claim 8,
the soft-off protection module comprises a sixth switching tube, a second diode, a third diode, a sixth resistor, a seventh resistor, an eighth resistor and a ninth resistor;
a first end of the sixth switching tube is electrically connected with a first end of the ninth resistor, a second end of the ninth resistor is electrically connected with a first end of the eighth resistor and a control end of the first switching tube, a second end of the eighth resistor is electrically connected with an input end of the voltage stabilizing module, and a second end of the sixth switching tube is grounded; the control end of the sixth switching tube is electrically connected with the cathode of the second diode and the cathode of the third diode, the anode of the second diode is electrically connected with the system hardware switch through the sixth resistor, and the anode of the third diode is electrically connected with the system soft switch through the seventh resistor.
10. A PLC power supply characterized by comprising the PLC power supply front end EMC protection circuit of any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021781992.3U CN212305141U (en) | 2020-08-24 | 2020-08-24 | PLC power front end EMC protection circuit and PLC power |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021781992.3U CN212305141U (en) | 2020-08-24 | 2020-08-24 | PLC power front end EMC protection circuit and PLC power |
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| Publication Number | Publication Date |
|---|---|
| CN212305141U true CN212305141U (en) | 2021-01-05 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
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| CN202021781992.3U Active CN212305141U (en) | 2020-08-24 | 2020-08-24 | PLC power front end EMC protection circuit and PLC power |
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| Country | Link |
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| CN (1) | CN212305141U (en) |
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