CN111711171B - Power protection circuit and servo driver - Google Patents
Power protection circuit and servo driver Download PDFInfo
- Publication number
- CN111711171B CN111711171B CN202010559805.5A CN202010559805A CN111711171B CN 111711171 B CN111711171 B CN 111711171B CN 202010559805 A CN202010559805 A CN 202010559805A CN 111711171 B CN111711171 B CN 111711171B
- Authority
- CN
- China
- Prior art keywords
- voltage
- module
- power
- power supply
- diode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/04—Details with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Protection Of Static Devices (AREA)
Abstract
The embodiment of the invention discloses a power supply protection circuit and a servo driver. The power protection circuit includes: the device comprises a voltage sampling module, a logic judgment module and a power on-off control module; the voltage sampling module is used for collecting a first voltage of a first power supply end and sending the first voltage to the logic judgment module; the logic judgment module is used for sending a reverse connection fault signal to the power supply on-off control module when the first voltage is smaller than a first preset value; and the power supply on-off control module is used for controlling the power supply not to supply power to the circuit to be supplied according to the reverse connection fault signal. The power supply protection circuit provided by the embodiment of the invention is used for solving the problem that once the positive electrode and the negative electrode of a power supply are connected reversely in a direct current system, unpredictable dangers are generated.
Description
Technical Field
The embodiment of the invention relates to the technical field of power electronics, in particular to a power supply protection circuit and a servo driver.
Background
At present, many electronic products need an external power supply, and in all direct current input systems, the input power supply is direct current, and an important point different from a common alternating current input system is that the direct current input by the direct current system is required to be directional, and once the positive electrode and the negative electrode of the power supply are connected reversely, a phenomenon that a large area of the inside of the direct current system is burnt out easily occurs, and unpredictable dangers are generated.
Disclosure of Invention
The embodiment of the invention provides a power supply protection circuit and a servo driver, which are used for solving the problem that once the positive electrode and the negative electrode of a power supply are connected reversely in a direct current system, unpredictable dangers are generated.
In a first aspect, an embodiment of the present invention provides a power protection circuit, including: the device comprises a voltage sampling module, a logic judgment module and a power on-off control module;
the voltage sampling module is used for collecting a first voltage of a first power supply end and sending the first voltage to the logic judgment module;
the logic judgment module is used for sending a reverse connection fault signal to the power supply on-off control module when the first voltage is smaller than a first preset value;
and the power supply on-off control module is used for controlling the power supply not to supply power to the circuit to be supplied according to the reverse connection fault signal.
Optionally, the voltage sampling module includes at least two loads and a voltage sampling unit; the at least two loads include a first load and a second load; the first load and the second load have different voltage drops; a first end of the first load is electrically connected with the first power end and a first input end of the sampling unit respectively, a second end of the first load is electrically connected with a first end of the second load and a second input end of the voltage sampling unit respectively, and a second end of the second load is electrically connected with a second power end and a third input end of the voltage sampling unit respectively;
the voltage sampling module is further configured to collect a second voltage at a second end of the first load, and send the second voltage to the logic determination module;
the logic judgment module is further used for sending a too-low fault signal to the power supply on-off control module after the first voltage is determined to be greater than or equal to the first preset value and when the second voltage is determined to be smaller than a second preset value;
and the power supply on-off control module is used for controlling the power supply not to supply power to the circuit to be powered according to the over-low fault signal.
Optionally, the logic determining module is further configured to send an over-high fault signal to the power supply on-off control module after determining that the second voltage is greater than or equal to the second preset value and when determining that the second voltage is greater than a third preset value;
and the power supply on-off control module is used for controlling the power supply not to supply power to the circuit to be supplied according to the overhigh fault signal.
Optionally, the method further includes: the device comprises a rectification module and a voltage conversion module;
a first input end of the rectifying module is electrically connected with the first power supply end, a second input end of the rectifying module is electrically connected with the second power supply end, and an output end of the rectifying module is electrically connected with an input end of the voltage conversion module;
the output end of the voltage conversion module is electrically connected with the voltage sampling module and the logic judgment module respectively.
Optionally, the rectifying module includes a first diode, a second diode, a third diode and a fourth diode;
the cathode of the first diode is electrically connected with the first power end and the anode of the second diode respectively, the cathode of the second diode is electrically connected with the input end of the voltage conversion module and the cathode of the fourth diode respectively, the anode of the fourth diode is electrically connected with the cathode of the third diode and the second power end respectively, and the anode of the third diode and the anode of the first diode are grounded respectively.
Optionally, the voltage sampling module further includes a first protection unit and a first voltage drop cancellation unit;
the first protection unit is disposed between the first power source terminal and a first terminal of the first load;
the first voltage drop counteracting unit is arranged between the second power supply end and the second end of the second load;
wherein the first voltage is a voltage between the first load and the first protection unit.
Optionally, the first voltage drop canceling unit includes a fifth diode; the voltage drop of the third diode is the same as that of the fifth diode.
Optionally, the voltage sampling module further includes a second protection unit and a second voltage drop cancellation unit;
the second protection unit is arranged between the second power supply terminal and a second terminal of the second load;
the second voltage drop canceling unit is disposed between the first power terminal and a first terminal of the first load;
wherein the first voltage is a voltage between the first load and the second voltage drop canceling unit.
Optionally, the second voltage drop canceling unit includes a seventh diode; the voltage drop of the seventh diode is the same as that of the first diode.
Optionally, the voltage sampling module further includes a third protection unit;
the first end of the first load, the second end of the first load and the second end of the second load are respectively and electrically connected with the first end of the third protection unit, and the second end of the third protection unit is respectively and electrically connected with the first input end, the second input end and the third input end of the voltage sampling unit.
Optionally, the method further includes: an alarm module;
the alarm module is electrically connected with the logic judgment module.
In a second aspect, an embodiment of the present invention further provides a servo driver, including: the power protection circuit of the first aspect.
According to the technical scheme provided by the embodiment, the first voltage of the first power end is compared with the first preset value through the logic judgment module, when the first voltage is smaller than the first preset value, the anode and the cathode of the power supply are connected reversely, and at the moment, a reverse connection fault signal is sent to the power on-off control module, so that the power on-off control module controls the power supply not to supply power to the circuit to be supplied with power, and therefore the problem that once the anode and the cathode of the power supply are connected reversely in the direct current system in the prior art, a large area of the interior of the direct current system is burnt is solved; in addition, compared with the reverse connection prevention by using the unidirectional conduction characteristic of the diode, the power consumption of the power protection circuit provided by the embodiment is smaller when the power protection circuit is applied to a high-power device.
Drawings
Fig. 1 is a schematic structural diagram of a power protection circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another power protection circuit according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of another power protection circuit according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a partial structure of a power protection circuit according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of another power protection circuit according to an embodiment of the present invention;
fig. 6 is a schematic diagram of a partial structure of another power protection circuit according to an embodiment of the present invention;
fig. 7 is a schematic diagram of a partial structure of another power protection circuit according to an embodiment of the present invention;
FIG. 8 is a flow chart of logic determination of a logic determination module according to an embodiment of the present invention;
fig. 9 is a schematic structural diagram of a servo driver according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the 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 structures related to the present invention are shown in the drawings, not all of them.
Fig. 1 is a schematic structural diagram of a power protection circuit according to an embodiment of the present invention, and as shown in fig. 1, a power protection circuit 100 according to the embodiment includes: the device comprises a voltage sampling module 10, a logic judgment module 20 and a power on-off control module 30; the voltage sampling module 10 is configured to collect a first voltage at a first power end, and send the first voltage to the logic determining module 20; the logic judgment module 20 is configured to determine that when the first voltage is smaller than a first preset value, a reverse connection fault signal is sent to the power on-off control module 30; the power on-off control module 30 is used for controlling the power supply not to supply power to the circuit to be supplied according to the reverse connection fault signal.
Under normal conditions, the first power supply end P is connected with the positive electrode of the power supply, and the second power supply end N is connected with the negative electrode of the power supply.
Illustratively, the voltage value of the power supply is 30V, when the positive and negative poles of the power supply are connected in reverse, i.e. the first power supply terminal P is connected to the negative pole of the power supply, and the second power supply terminal N is connected to the positive pole of the power supply, the voltage of the first power supply terminal P is 0, and the voltage of the second power supply terminal N is 30V. The voltage sampling module 10 collects a voltage at the first power end P, that is, a first voltage, the first voltage at this time is 0, and sends the first voltage to the logic judgment module 30, and the logic judgment module 30 compares the first voltage with a first preset value, where the first preset value may be set according to a voltage value of a positive electrode of the power supply when the power supply is reversely connected, for example, the first preset value may be 0.01V, when it is determined that the first voltage is smaller than the first preset value, it indicates that the positive electrode and the negative electrode of the power supply are reversely connected, and at this time, a reverse connection fault signal is sent to the power supply on-off control module 30, so that the power supply on-off control module 30 controls the power supply not to supply power to the circuit to be supplied with power. Optionally, the voltage sampling module 10 may collect the first voltage of the first power source end P twice continuously, and average the collected first voltages twice, so as to prevent the detection accuracy from being affected by the existence of errors, and enhance the system reliability.
It should be noted that the first preset value may be set according to an actual situation, and this embodiment is not particularly limited as long as it is detected that the positive electrode and the negative electrode of the power supply are reversely connected.
Optionally, the logic determination module 20 may include, for example, a Micro Controller Unit (MCU), but the embodiment is not limited thereto as long as the logic determination can be performed. The power on-off control module 30 may include a switching element such as a relay, a transistor, or an MOS transistor, for example, and when the power on-off control module 30 is a switching element such as a relay, a transistor, or an MOS transistor, the reverse fault signal may be, for example, a high level or a low level.
According to the technical scheme provided by the embodiment, the first voltage of the first power end is compared with the first preset value through the logic judgment module, when the first voltage is smaller than the first preset value, the anode and the cathode of the power supply are connected reversely, and at the moment, a reverse connection fault signal is sent to the power on-off control module, so that the power on-off control module controls the power supply not to supply power to the circuit to be supplied with power, and therefore the problem that once the anode and the cathode of the power supply are connected reversely in the direct current system in the prior art, a large area of the interior of the direct current system is burnt is solved; in addition, compared with the reverse connection prevention by using the unidirectional conduction characteristic of the diode, the power consumption of the power protection circuit provided by the embodiment when applied to a high-power device is also smaller.
Optionally, fig. 2 is a schematic structural diagram of another power protection circuit provided in an embodiment of the present invention, and as shown in fig. 2, the voltage sampling module 10 includes at least two loads and a voltage sampling unit 11; the at least two loads include a first load 12 and a second load 13; the first load 12 and the second load 13 have different voltage drops; a first end of the first load 12 is electrically connected to the first power terminal P and a first input terminal of the voltage sampling unit 11, a second end of the first load 12 is electrically connected to a first end of the second load 13 and a second input terminal of the voltage sampling unit 11, and a second end of the second load 13 is electrically connected to the second power terminal N and a third input terminal of the voltage sampling unit 11; the voltage sampling module 10 is further configured to collect a second voltage at a second end of the first load 12, and send the second voltage to the logic determining module 20; the logic judgment module 20 is further configured to send an excessively low fault signal to the power on-off control module 30 after determining that the first voltage is greater than or equal to the first preset value and when determining that the second voltage is less than the second preset value; the power on-off control module 30 is used for controlling the power supply not to supply power to the circuit to be supplied according to the too low fault signal.
The voltage sampling unit 11 may include, for example, an Analog to Digital Converter (ADC), and the voltage sampling unit 11 converts the acquired signal into a signal that can be recognized by the logic determining module 30.
Specifically, the minimum voltage value required to be input by the circuit to be powered is U 1 That is, the power supply voltage of the circuit to be powered cannot be lower than this value, and if the power supply voltage is lower than this value, damage may be caused to the circuit to be powered. When the voltage value of the power supply is U 1 Of the first load 12Voltage at the second terminal
When the voltage at the second terminal of the first load 12 is less than
While, correspondingly, the voltage value of the power supply is less than U 1 So that the second preset value can be set to
U 2 At a second preset value, U 1 Minimum voltage value, U, required to be input for the circuit to be supplied 12 Is the voltage drop, U, of the first load 12 13 When the second voltage is lower than the second preset value, it indicates that the voltage value of the power supply is too low, which is the voltage drop of the second load 13.
Illustratively, the first load 12 is a first resistor, the second load 13 is a second resistor, the resistance of the first resistor is 11K Ω, the resistance of the second resistor is 1K Ω, and the required input voltage of the circuit to be powered can not be lower than 24V at the lowest, then if the input voltage difference of the circuit to be powered is 24V, the voltage value of the first end of the first resistor is 24V, and the voltage value of the second end of the first resistor is 24V
The second preset value may be, for example, 2V.
Specifically, in this embodiment, a first voltage is collected first, and the logic determination module 20 determines whether a second voltage at the second end of the first load 12 is smaller than a second preset value on the premise that the positive electrode and the negative electrode of the power supply are not connected reversely, and if the second voltage is smaller than the second preset value, which indicates that the voltage value of the power supply is too low, sends a too-low fault signal to the power supply on-off control module 20, so that the power supply on-off control module 20 controls the power supply not to supply power to the circuit to be powered.
The first load 12 and the second load 13 may be devices having a voltage difference, such as resistors. It should be noted that the number of loads is not limited in this embodiment.
According to the technical scheme, on the premise that the positive electrode and the negative electrode of the power supply are not reversed, whether the voltage value of the power supply is too low is judged by judging whether the second voltage is smaller than the second preset value or not, and compared with the method that whether the voltage value of the collected power supply is smaller than the set voltage value or not is directly judged.
On the basis of the above scheme, optionally, referring to fig. 2 continuously, the logic determining module 20 is further configured to determine that, after the second voltage is greater than or equal to the second preset value and it is determined that the second voltage is greater than the third preset value, send an excessive fault signal to the power on-off control module 30; the power on-off control module 30 is used for controlling the power supply not to supply power to the circuit to be powered according to the overhigh fault signal.
Specifically, the maximum voltage value required to be input by the circuit to be powered is U 3 That is, the power supply voltage of the circuit to be powered cannot be higher than this value, and if the power supply voltage is higher than this value, damage may be caused to the circuit to be powered. Then when the voltage value of the power supply is U 3 The voltage at the second terminal of the first load 12
When the voltage at the second terminal of the first load 12 is greater than
When the voltage value of the power supply is larger than U correspondingly 3 So that the third preset value can be set to
U 4 At a third preset value, U 3 Maximum voltage value, U, required for input to the circuit to be supplied 12 Is the voltage drop, U, of the first load 12 13 When the second voltage is greater than the third preset value, it indicates that the voltage value of the power supply is too high, which is the voltage drop of the second load 13.
Illustratively, the first load 12 is a first resistor, the secondThe two loads 13 are second resistors, the resistance of the first resistor is 11K Ω, the resistance of the second resistor is 1K Ω, the required input voltage of the circuit to be powered cannot be higher than 60V at the lowest, if the input voltage difference of the circuit to be powered is 60V, the voltage value of the first end of the first resistor is 60V, and the voltage value of the second end of the first resistor is 60V
The third preset value may be, for example, 5V.
Specifically, in this embodiment, it is first determined whether the positive electrode and the negative electrode of the power supply are connected reversely, then it is determined whether the voltage value of the power supply is too low, then it is determined whether the voltage value of the power supply is greater than a third preset value, when the second voltage is greater than the third preset value, an excessively high fault signal is sent to the power on-off control module 30, so that the power on-off control module 30 controls the power supply not to supply power to the circuit to be supplied, and when the second voltage is less than or equal to the third preset value, a normal signal is sent to the power on-off control module 30, so that the power on-off control module 30 controls the power supply to supply power to the circuit to be supplied.
According to the technical scheme, comprehensive logic judgment is performed, so that comprehensive protection effects of reverse connection protection of the input power supply, excessively low input voltage value and excessively high input voltage value are achieved, the accuracy of input fault detection is further improved, and high safety is achieved.
Optionally, fig. 3 is a schematic structural diagram of another power protection circuit provided in the embodiment of the present invention, and as shown in fig. 3, the power protection circuit 100 provided in the embodiment of the present invention further includes: a rectification module 40 and a voltage conversion module 50; a first input end of the rectifying module 40 is electrically connected with the first power supply end P, a second input end of the rectifying module 40 is electrically connected with the second power supply end N, and an output end of the rectifying module 40 is electrically connected with an input end of the voltage conversion module 50; the output end of the voltage conversion module 50 is electrically connected to the voltage sampling module 10 and the logic determination module 20, respectively.
Specifically, the direction of the output current of the output end of the rectifying module 40 is fixed no matter the first power supply end P and the second power supply end N have any direction of current input through the rectifying module 40, and even if the positive electrode and the negative electrode of the power supply are reversely connected, the voltage sampling module 10 and the logic judgment module 20 can normally work, so that the comprehensive protection effects of reverse connection of the input power supply, over-low input voltage value and over-high input voltage value can be achieved when the positive electrode and the negative electrode of the power supply are reversely connected. The voltage conversion module 50 can convert the voltage provided by the power supply to convert the specific voltage used by the voltage sampling module 10 and the logic determination module 20, so as to supply power to the voltage sampling module 10 and the logic determination module 20.
Optionally, the voltage converting module 50 may be implemented by, for example, a chip with a model number of SX3700 or a chip with a model number of XD308H, and the like, where the voltage converting module 50 has a function of converting a high voltage into a low voltage, and the chip is characterized in that an input end can receive a high voltage of several hundred volts, and an amplitude of the low voltage at an output end can be adjusted according to a requirement by using peripheral parameters. Illustratively, the voltage conversion module 50 is a chip of type SX3700, which outputs, for example, 5V after performing voltage conversion, and is used to supply power to the voltage sampling module 10 and the logic determination module 20.
In this embodiment, through setting up independent rectifier module and voltage conversion module for also can normally work under the condition that the positive negative pole of power connects conversely, for voltage sampling module and logic judgment module power supply, possess very strong power adaptability, provide the guarantee for the logic judgment of voltage sampling module and logic judgment module.
Optionally, fig. 4 is a schematic diagram of a partial structure of a power protection circuit according to an embodiment of the present invention, and as shown in fig. 4, the rectifying module 40 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4; a cathode of the first diode D1 is electrically connected to the first power terminal P and an anode of the second diode D2, respectively, a cathode of the second diode D2 is electrically connected to the input terminal of the voltage conversion module 50 and a cathode of the fourth diode D4, respectively, an anode of the fourth diode D4 is electrically connected to a cathode of the third diode D3 and the second power terminal N, respectively, and an anode of the third diode D3 and an anode of the first diode D1 are grounded, respectively.
The rectifying module 40 is composed of a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4. It is understood that the rectifying module 40 is not limited to this structure as long as the direction of the output current of the rectifying module 40 is fixed regardless of the input of the current of any direction at the first power terminal P and the second power terminal N.
Optionally, with reference to fig. 4, for example, the power protection circuit 100 may further include a filter capacitor C1, where a first electrode of the filter capacitor C1 is electrically connected to the output terminal of the voltage conversion module 50, and a second electrode of the filter capacitor C1 is grounded, and is configured to filter the voltage value output by the voltage conversion module 50, so as to improve reliability of the circuit.
Optionally, fig. 5 is a schematic structural diagram of another power protection circuit provided in an embodiment of the present invention, and as shown in fig. 5, the voltage sampling module 10 further includes a first protection unit 14 and a first voltage drop canceling unit 15; the first protection unit 14 is disposed between the first power source terminal P and the first terminal of the first load 12; the first voltage drop canceling unit 15 is disposed between the second power terminal N and the second terminal of the second load 13; the first voltage is a voltage between the first load 12 and the first protection unit 14.
In consideration of the voltage difference caused by the forward voltage drop of the diode conduction in the rectifier module, the voltage sampling unit 11 may have a negative value, which may cause the voltage sampling unit 11 to be damaged. Therefore, in the present embodiment, the first voltage drop canceling unit 15 is disposed between the second power end N and the second end of the second load 13, and when a forward power is input, the first voltage drop canceling unit 15 cancels a voltage difference caused by a forward voltage drop caused by conduction of a diode in the rectifier module, so as to avoid a problem that the voltage sampling unit 11 is damaged due to a negative value possibly occurring in the sampling voltage unit 11. Further, by disposing the first protection unit 14 between the first load 12 and the first power source terminal P, a problem that the voltage sampling unit 11 is damaged when the first power source terminal P inputs a negative voltage, that is, a negative value may occur in the voltage sampling unit 11, is avoided.
Optionally, the first voltage drop canceling unit 15 includes a fifth diode; the voltage drop of the third diode is the same as that of the fifth diode. Alternatively, the first protection unit 14 may include, for example, a sixth diode.
The functions of the first protection unit 14 and the first voltage drop canceling unit 15 will be further explained when the first voltage drop canceling unit 15 includes a fifth diode and the first protection unit 14 includes a sixth diode, wherein the first load 12 is taken as the first resistor R1 and the second load 13 is taken as the second resistor R2, but the invention is not limited thereto. It should be noted that fig. 6 shows only a part of the devices, not all of the devices, in order to clearly express the functions of the first protection unit 14 and the first voltage drop canceling unit 15.
Referring to fig. 6, when a forward power is input, i.e., the first power terminal P is connected to the positive power source, and the second power terminal N is connected to the negative power source, a voltage drop, for example, V, exists due to the diodes (including the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, the fifth diode D5, the sixth diode D6, and the seventh diode D7 and the eighth diode D8 mentioned in the following embodiments, which are not described in detail in the following embodiments) such that the voltage drop is V F The anode of the diode is necessarily higher than the cathode potential of the diode by V as long as the diode is in forward conduction F . As shown in fig. 6, when a forward power is input, the second diode D2 and the third diode D3 in the rectifier module are turned on to form a circuit, since the middle electrode of the voltage conversion module 50 is a ground pin, that is, a 0-potential point in the whole circuit, that is, the anode of the third diode D3, then, since the potential difference between the two ends of the third diode D3 is V F Then the potential at the second power supply terminal N is 0V-V F ＝-V F If the potential difference between the first power source terminal P and the second power source terminal N is Δ U, the potential at the first power source terminal P is Δ U + U n ＝ΔU-V F (ii) a When the forward power is input, the fifth diode D5 and the sixth diode D6 are turned on, and the voltage difference across the fifth diode D5 and the sixth diode D6 is also V F So the potential at the point between the fifth diode D5 and the second resistor R2 is U n ＝-V F +V F 0V, and the potential between the sixth diode D6 and the first resistor R1 is U p ＝ΔU-V F -V F That isThe point between the first resistor R1 and the second resistor R2 is at a potential of
If the fifth diode D5 is not provided between the second resistor R2 and the second power source terminal N, the potential of the point between the fifth diode D5 and the second resistor R2 is U n ＝-V F The voltage collected by the voltage sampling unit 11 will be a negative value, resulting in damage to the voltage sampling unit 11; if the sixth diode D6 is not provided between the first resistor R1 and the first power source terminal P, when the input of the first power source terminal P is a negative voltage, the voltage sampled by the voltage sampling unit 11 is a negative value, resulting in damage to the voltage sampling unit 11.
Optionally, with continued reference to fig. 5, the voltage sampling module 10 further includes a second protection unit 16 and a second voltage drop canceling unit 17; the second protection unit 16 is disposed between the second power terminal N and the second terminal of the second load 13; the second voltage drop canceling unit 17 is disposed between the first power terminal P and the first terminal of the first load 12; the first voltage is a voltage between the first load 12 and the second voltage drop canceling unit 17.
In consideration of the voltage difference caused by the forward voltage drop of the diode conduction in the rectifier module, the voltage sampling unit 11 may have a negative value, which may cause the voltage sampling unit 11 to be damaged. Therefore, in the present embodiment, by disposing the first power source terminal P between the first power source terminal P and the first end of the first load 12, and when a negative power source is input, the second voltage drop counteracting unit 17 counteracts the voltage difference caused by the positive voltage drop of the diode in the rectifier module, so as to avoid the problem that the voltage sampling unit 11 is damaged due to the negative value of the voltage sampling unit 11. In addition, by disposing the second protection unit 16 between the second power terminal N and the second terminal of the second load 13, a problem that the voltage sampling unit 11 is damaged when the second power terminal N inputs a negative voltage, i.e., a negative value may occur in the voltage sampling unit 11, is avoided.
Optionally, the second voltage drop canceling unit 17 includes a seventh diode; the voltage drop of the seventh diode is the same as that of the first diode. Alternatively, the second protection unit 16 may protect, for example, the eighth diode.
The functions of the second protection unit 16 and the second voltage drop canceling unit 17 will be further explained when the second voltage drop canceling unit 17 includes a seventh diode and the second protection unit 16 includes an eighth diode, wherein the first load 12 is taken as the first resistor R1 and the second load 13 is taken as the second resistor R2, but the present application is not limited thereto. It should be noted that fig. 7 only shows a part of the devices, not all the devices, in order to clearly express the functions of the second protection unit 16 and the second voltage drop canceling unit 17.
Referring to fig. 7, when a negative power is input, i.e. the first power terminal P is connected to the negative electrode of the power supply, and the second power terminal N is connected to the positive electrode of the power supply, as shown in fig. 7, at this time, due to the reverse direction of the power supply, the first diode D1 and the fourth diode D4 of the rectifying module are conducted in the forward direction to form a path, which is also the ground 0 potential of the middle electrode of the voltage converting module 50, and is the anode of the first diode D1 at this time. Since the voltage difference across the first diode D1 is also V F Then the potential at the first power supply terminal P is 0-V F ＝-V F The potential at the second power supply terminal N is DeltaU-V F (ii) a When a negative power is input, the seventh diode D7 and the eighth diode D8 are turned on, and the potential of a point between the seventh diode D7 and the first resistor R1 is U p ＝-V F +V F The potential at the point between the eighth diode D8 and the second resistor R2 is U, 0V n ＝ΔU-V F -V F Potential of a point between the first resistor R1 and the second resistor R2
If the seventh diode D7 is not provided between the first resistor R1 and the first power source terminal P, the potential of the point between the seventh diode D7 and the first resistor R1 is U p ＝-V F The voltage collected by the voltage sampling unit 11 will be a negative value, resulting in damage to the voltage sampling unit 11; if between the second resistor R1 and the second power supply terminal NThe eighth diode D8 is not provided, and when the input of the second power terminal N is a negative voltage, the voltage sampled by the voltage sampling unit 11 is a negative value, resulting in damage to the voltage sampling unit 11.
Optionally, with continued reference to fig. 2, the voltage sampling module 10 further includes a third protection unit 16; a first end of the first load 12, a second end of the first load 12, and a second end of the second load 13 are electrically connected to a first end of a third protection unit 16, respectively, and a second end of the third protection unit 16 is electrically connected to a first input end, a second input end, and a third input end of the voltage sampling unit 11, respectively.
The third protection unit 16 may include a current-limiting resistor or a clamping diode, for example, and due to the existence of the third protection unit 16, when a higher voltage is input to the first power source terminal P and the second power source terminal N, the voltage sampling unit 11 is not damaged. For example, the voltage sampling unit 11 is an ADC chip, and the maximum voltage range allowed to be input by the ADC chip can reach 0 to 5V under the condition of 5V power supply, and due to the third protection unit 16, when the input voltage is higher, saturation occurs, and the ADC chip is not damaged.
Optionally, with continued reference to fig. 1, the power protection circuit 100 further includes: an alarm module 60; the alarm module 60 is electrically connected with the logic judgment module 20. The user is prompted by the alarm module 60.
The alarm module 60 may include, for example, an LED indicator light. For example, when the logic determination module 20 determines that different faults (power supply is connected reversely, power supply voltage is too low, or power supply voltage is too high), different LED indicator lamps are controlled to be turned on to indicate which kind of fault the current input is, and meanwhile, a fault signal is sent to the power supply on-off control module 30, so that the power supply on-off control module 30 controls the power supply not to supply power to the circuit to be supplied with power; if no fault exists, the indicator light is not lightened, and meanwhile, a normal signal is sent to the power supply on-off control module 30, so that the power supply on-off control module 30 controls the power supply to supply power to the circuit to be powered.
On the basis of the above embodiments, in order to clearly show the whole principle process of the present application, the present application will be exemplified with reference to specific examples in order to illustrate the present applicationMore conveniently and clearly describing the following examples, the circuit to be powered is a servo driver, the voltage sampling unit 11 is an ADC chip, the chip allows the maximum input voltage to reach 0-5V in the case of 5V power supply, the first load 12 is a first resistor R1 with a resistance value of 11k Ω, the second load 13 is a second resistor R2 with a resistance value of 1k Ω, the rectifying module 40 includes a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4, the first voltage drop canceling unit 15 includes a fifth diode D5, the first protection unit 14 includes a sixth diode D6, the second protection unit 16 includes an eighth diode D8, the second voltage drop canceling unit 17 includes a seventh diode D7, and the forward conduction voltage drop V of the selected diodes D1-D8 F For example, 0.7V, the following example is not intended to limit the present application.
It is assumed that the servo driver requires that the input voltage must not be lower than 24V at minimum and must not exceed 60V at maximum, otherwise, undervoltage and overvoltage alarms are respectively performed.
Due to the arrangement of the rectifying module 40 and the voltage converting module 50, the voltage difference between the first power supply terminal P and the second power supply terminal N can be stably output 5V as long as it exceeds about 8V (the actual value depends on the selected chip model), regardless of whether the first power supply terminal P and the second power supply terminal N have reverse connection faults or not.
In case one, assuming that the positive and negative electrodes of the power supply are reversed, referring to fig. 7, for example, the first power supply terminal P is connected to the negative electrode of the power supply, the second power supply terminal N is connected to the positive electrode of the power supply, and the power supply voltage difference is 30V, the potential of the point between the sixth diode D6 and the first resistor R1 is U p ＝-V F +V F 0V. The potential of the point between the eighth diode D8 and the second resistor R2 is U n ＝ΔU-V F -V F 30-0.7-28.6V, the potential at the point between the first resistor R1 and the second resistor R2
At this time, due to U Z And U n Has exceeded the sampling range of the ADC and thus its sampling value is the maximum value. So at this time U p ＝0V，U Z Maximum, U n And maximum.
And in the second case, if the positive electrode and the negative electrode of the power supply are not reversed and the input voltage difference is 30V, continuing to refer to FIG. 6, U n The voltage is 0V; u shape p ＝ΔU-V F -V F ＝30-0.7-0.7＝28.6V，
So at this time U p Maximum, U Z Is 2.38V, U n ＝0V。
And in case three, assuming that the positive electrode and the negative electrode of the power supply are not reversed, the input voltage difference is 24V, and continuing to refer to fig. 6, then Un is 0V, U p ＝ΔU-V F -V F ＝24-0.7-0.7＝22.6V，
So at this time U p Maximum, U Z Is 1.88V, U n ＝0V。
And in case four, assuming that the positive electrode and the negative electrode of the power supply are not reversed, the input voltage difference is 60V, and continuing to refer to fig. 6, Un is equal to 0V, U p ＝ΔU-V F -V F ＝60-0.7-0.7＝58.6V，
So at this time U p Maximum, U Z Is 4.88V, U n ＝0V。
From the above description of the case 4, the following table 1 can be obtained, in which the sampled values of the point voltages in four different cases are listed.
TABLE 1 Voltage sampling values at various points under different input conditions
| U p | U Z | U n | |
| Positive and negative are connected inversely | 0 | Maximum of | Maximum of |
| Low voltage | Maximum of | Less than 1.88 |
0 |
| Over-voltage | Maximum of | Greater than 4.88 |
0 |
| Normal voltage | Maximum of | Greater than 1.88V and less than 4.88 |
0 |
The logic judgment module acquires the sampling value U of the current ADC p 、U a 、U n Then, the determination may be made according to the following process, wherein fig. 8 is a logic determination flowchart of a logic determination module provided in an embodiment of the inventionWherein the first voltage is a set relatively small voltage value, such as 0.01V, below which the value of the voltage taken is zero; the second preset value is a set threshold value which is too low, and as in the above example, the sampling value corresponding to 24V is 1.88V, here, the second preset value can be set to 1.8V, and if the sampling value is lower than 1.8V, the input voltage is considered to be lower than 24V; the third preset value is a set voltage too high threshold, and 60V corresponds to a sample value of 4.88V as in the above example, where the third preset value can be set to 4.95V, and an input voltage higher than 60V is considered to be higher than 4.95V. When the logic judgment module judges the input fault, different LED indicating lamps are controlled to be lightened to indicate the current input fault, and a fault signal is sent to the power supply on-off control module 30 at the same time, so that the power supply on-off control module 30 controls the power supply not to supply power to the circuit to be powered; if no fault exists, the indicator lamp is not lightened, and a normal signal is sent to the power on-off control module 30 at the same time, so that the power on-off control module 30 controls the power supply to supply power to the circuit to be powered. For the control of the LED indicator, a general high-level LED lamp lighting mode may be used, and the specific circuit connection is not described herein again. In addition, for the processing flow of the logic judgment module, a time delay link can be added or data can be subjected to average processing to enhance the anti-interference performance of sampling, prevent false triggering and enhance the reliability of the system.
The embodiment of the present invention further provides a servo driver, and fig. 9 is a schematic structural diagram of a servo driver provided in the embodiment of the present invention. As shown in fig. 9, the servo driver 200 includes the power protection circuit 100 in the above embodiment, and therefore the servo driver 200 provided in the embodiment of the present invention also has the beneficial effects described in the above embodiment, and the description thereof is omitted here.
It should be noted that the present invention is not limited to the field of dc servo drivers, and can be applied to almost all dc input devices.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. 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 some detail by the above embodiments, the invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the invention, and the scope of the invention is determined by the scope of the appended claims.
Claims (10)
1. A power protection circuit, comprising: the device comprises a voltage sampling module, a logic judgment module and a power on-off control module;
the voltage sampling module is used for collecting a first voltage of a first power supply end and sending the first voltage to the logic judgment module;
the logic judgment module is used for sending a reverse connection fault signal to the power supply on-off control module when the first voltage is smaller than a first preset value;
the power supply on-off control module is used for controlling a power supply not to supply power to a circuit to be supplied according to the reverse connection fault signal;
the voltage sampling module comprises at least two loads and a voltage sampling unit; the at least two loads comprise a first load and a second load; the first load and the second load have different voltage drops; a first end of the first load is electrically connected with the first power end and a first input end of the sampling unit respectively, a second end of the first load is electrically connected with a first end of the second load and a second input end of the voltage sampling unit respectively, and a second end of the second load is electrically connected with a second power end and a third input end of the voltage sampling unit respectively;
the voltage sampling module is further configured to collect a second voltage at a second end of the first load, and send the second voltage to the logic determination module;
the logic judgment module is further used for sending a low fault signal to the power supply on-off control module after the first voltage is determined to be greater than or equal to the first preset value and when the second voltage is determined to be smaller than a second preset value;
the power supply on-off control module is used for controlling the power supply not to supply power to the circuit to be powered according to the over-low fault signal;
the voltage sampling module also comprises a first protection unit and a first voltage drop offset unit;
the first protection unit is disposed between the first power source terminal and a first terminal of the first load;
the first voltage drop counteracting unit is arranged between the second power supply end and the second end of the second load;
wherein the first voltage is a voltage between the first load and the first protection unit.
2. The power protection circuit according to claim 1, wherein the logic determining module is further configured to send an excessive fault signal to the power on-off control module when it is determined that the second voltage is greater than or equal to the second preset value and it is determined that the second voltage is greater than a third preset value;
and the power supply on-off control module is used for controlling the power supply not to supply power to the circuit to be supplied according to the overhigh fault signal.
3. The power protection circuit of claim 1, further comprising: the device comprises a rectifying module and a voltage conversion module;
a first input end of the rectifying module is electrically connected with the first power supply end, a second input end of the rectifying module is electrically connected with the second power supply end, and an output end of the rectifying module is electrically connected with an input end of the voltage conversion module;
the output end of the voltage conversion module is electrically connected with the voltage sampling module and the logic judgment module respectively.
4. The power protection circuit of claim 3, wherein the rectification module comprises a first diode, a second diode, a third diode, and a fourth diode;
the cathode of the first diode is electrically connected with the first power supply end and the anode of the second diode, the cathode of the second diode is electrically connected with the input end of the voltage conversion module and the cathode of the fourth diode, the anode of the fourth diode is electrically connected with the cathode of the third diode and the second power supply end, and the anode of the third diode and the anode of the first diode are grounded.
5. The power protection circuit according to claim 4, wherein the first voltage drop canceling unit includes a fifth diode; the voltage drop of the third diode is the same as that of the fifth diode.
6. The power protection circuit according to claim 4, wherein the voltage sampling module further comprises a second protection unit and a second voltage drop cancellation unit;
the second protection unit is arranged between the second power supply terminal and the second terminal of the second load;
the second voltage drop canceling unit is disposed between the first power terminal and a first terminal of the first load;
wherein the first voltage is a voltage between the first load and the second voltage drop canceling unit.
7. The power protection circuit according to claim 6, wherein the second voltage drop canceling unit includes a seventh diode; the voltage drop of the seventh diode is the same as that of the first diode.
8. The power protection circuit of claim 1, wherein the voltage sampling module further comprises a third protection unit;
the first end of the first load, the second end of the first load and the second end of the second load are respectively and electrically connected with the first end of the third protection unit, and the second end of the third protection unit is respectively and electrically connected with the first input end, the second input end and the third input end of the voltage sampling unit.
9. The power protection circuit of claim 1, further comprising: an alarm module;
the alarm module is electrically connected with the logic judgment module.
10. A servo driver comprising the power protection circuit of any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010559805.5A CN111711171B (en) | 2020-06-18 | 2020-06-18 | Power protection circuit and servo driver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010559805.5A CN111711171B (en) | 2020-06-18 | 2020-06-18 | Power protection circuit and servo driver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111711171A CN111711171A (en) | 2020-09-25 |
| CN111711171B true CN111711171B (en) | 2022-08-19 |
Family
ID=72541450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010559805.5A Active CN111711171B (en) | 2020-06-18 | 2020-06-18 | Power protection circuit and servo driver |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111711171B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114460834B (en) * | 2021-12-24 | 2024-06-14 | 东莞市李群自动化技术有限公司 | Power supply device, automatic control equipment and control method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006018923A1 (en) * | 2004-08-17 | 2006-02-23 | Rohm Co., Ltd | Power supply apparatus |
| WO2009089665A1 (en) * | 2008-01-15 | 2009-07-23 | Shenzhen Skyworth-Rgb Electronic Co., Ltd | Protection device for supply circuit with positive and negative double power |
| WO2013013415A1 (en) * | 2011-07-28 | 2013-01-31 | 深圳市良辉科技有限公司 | Ground wire safe voltage control system |
| CN205583659U (en) * | 2016-01-26 | 2016-09-14 | 广州视源电子科技股份有限公司 | Switching power supply circuit |
| CN106026358A (en) * | 2016-06-23 | 2016-10-12 | 京东方科技集团股份有限公司 | Automatic power supply switching apparatus and method, and power supply system |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010104075A (en) * | 2008-10-21 | 2010-05-06 | Yutaka Denki Seisakusho:Kk | Power supply circuit |
| CN104426139A (en) * | 2013-08-30 | 2015-03-18 | 深圳市海洋王照明工程有限公司 | Anti-reverse battery charging protecting circuit |
| CN204903740U (en) * | 2015-08-21 | 2015-12-23 | 湖北三江航天红峰控制有限公司 | Power detecting circuit |
| CN205987136U (en) * | 2016-08-30 | 2017-02-22 | 广州小百合信息技术有限公司 | Television board card power supply protection circuit |
| CN106848998B (en) * | 2017-02-28 | 2019-05-24 | 浙江大华技术股份有限公司 | A kind of power output protection circuit and device |
| CN108879648A (en) * | 2017-05-15 | 2018-11-23 | 华为技术有限公司 | A kind of power protecting circuit |
| CN109950879B (en) * | 2019-02-28 | 2020-05-19 | 珠海格力电器股份有限公司 | Charging protection device and method for power utilization circuit and circuit with charging protection function |
-
2020
- 2020-06-18 CN CN202010559805.5A patent/CN111711171B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006018923A1 (en) * | 2004-08-17 | 2006-02-23 | Rohm Co., Ltd | Power supply apparatus |
| WO2009089665A1 (en) * | 2008-01-15 | 2009-07-23 | Shenzhen Skyworth-Rgb Electronic Co., Ltd | Protection device for supply circuit with positive and negative double power |
| EP2178184A1 (en) * | 2008-01-15 | 2010-04-21 | Shenzhen Skyworth-RGB Electronic Co., Ltd. | Protection device for supply circuit with positive and negative double power |
| WO2013013415A1 (en) * | 2011-07-28 | 2013-01-31 | 深圳市良辉科技有限公司 | Ground wire safe voltage control system |
| CN205583659U (en) * | 2016-01-26 | 2016-09-14 | 广州视源电子科技股份有限公司 | Switching power supply circuit |
| CN106026358A (en) * | 2016-06-23 | 2016-10-12 | 京东方科技集团股份有限公司 | Automatic power supply switching apparatus and method, and power supply system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111711171A (en) | 2020-09-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9621068B2 (en) | Load driving circuit and method thereof | |
| US9401705B2 (en) | Gate driving device | |
| CN109342973B (en) | Direct current power supply input state monitoring circuit and system | |
| US9667055B2 (en) | Over-voltage protection apparatus and method of operating the same | |
| CN202373957U (en) | Over-voltage and under-voltage protection circuit | |
| US10257908B2 (en) | LED device protection circuit and method thereof | |
| KR20090086331A (en) | Lighting control unit for vehicle lighting fixture | |
| US9300198B2 (en) | Semiconductor device, including temperature sensing circut | |
| GB2468000A (en) | Over-current protection circuit and motor controller | |
| US20200403397A1 (en) | Switching controller with adaptive overheating protection | |
| US7369382B2 (en) | Integrated circuit with an undervoltage detector | |
| US11418023B2 (en) | Current protection circuit and method for high voltage system | |
| US20120092800A1 (en) | Circuit for detecting over-voltage and over-current | |
| CN108933527A (en) | Output over-voltage for converter is protected | |
| CN111711171B (en) | Power protection circuit and servo driver | |
| JP2011067037A (en) | Overvoltage protection circuit | |
| CN110829364A (en) | Electric leakage protection circuit, electric leakage protection device and electric equipment | |
| CN108181501B (en) | Current signal acquisition circuit with protective action | |
| WO2008021440A2 (en) | Buck converter fault detection method | |
| US20230353046A1 (en) | Totem pole power factor correction circuit | |
| US9013171B2 (en) | Method and apparatus for detecting a zero-voltage condition across four quadrant switches | |
| CN105720554B (en) | Overvoltage protection and its operating method | |
| JP5048458B2 (en) | Battery charger | |
| CN109361195A (en) | A kind of protection circuit against input over-voltage and power-supply system | |
| TW202017295A (en) | Power converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |