CN210803671U - Current detection and protection circuit of direct current motor - Google Patents
Current detection and protection circuit of direct current motor Download PDFInfo
- Publication number
- CN210803671U CN210803671U CN201921273128.XU CN201921273128U CN210803671U CN 210803671 U CN210803671 U CN 210803671U CN 201921273128 U CN201921273128 U CN 201921273128U CN 210803671 U CN210803671 U CN 210803671U
- Authority
- CN
- China
- Prior art keywords
- current
- circuit
- motor
- protection circuit
- current detection
- 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
Abstract
The utility model discloses a direct current motor's current detection and protection circuit, including accurate sampling resistance, current detection and protection circuit, high accuracy operational amplification circuit. The circuit is started along with a motor driving system, a precise sampling resistor samples the current of the motor in real time, and after the current is amplified by a current detection circuit for one time, the current passes through a current limiting protection circuit and is fed back to the motor driving system to realize current limiting protection; after the current after primary amplification is subjected to secondary filtering amplification through a high-precision operational amplification circuit, the current is detected at an AD sampling end and fed back to a motor driving circuit to realize the detection of the current; the adjustable resistor is added in the circuit, so that the current amplification factor and the current-limiting protection threshold value of the circuit can be adjusted according to actual requirements. The utility model discloses optimize the motor and make its setting at the most reasonable operating condition, reduce power consumption, prevent motor overload operation, avoid motor and other equipment to damage.
Description
Technical Field
The utility model relates to a current detection and protection circuit field especially relate to a direct current motor's current detection and protection circuit.
Background
The direct current motor has the characteristics of small volume, large torque, simple control and the like, and is widely applied to the field of industrial automation. However, in the application of the direct current motor, the speed of the encoder data of the motor is often detected to form speed closed-loop control, the current of the motor is generally not detected or is simply sampled and amplified, when the load is large, the motor cannot be in the most reasonable working state, the conditions of slow acceleration, hiccup running, motor overload, heating and the like occur, the electric energy loss is increased, and the motor and other equipment are damaged in severe cases.
Disclosure of Invention
The utility model aims at providing a direct current motor's current detection and protection circuit make the motor setting at the most reasonable operating condition, optimize the motor operation, reduce power consumption, prevent motor overload operation, avoid motor and other equipment to damage.
In order to realize the technical purpose, the utility model discloses a technical scheme does: a current detection and protection circuit of a direct current motor comprises a precise sampling resistor, a current detection and protection circuit and a high-precision operational amplification circuit.
Specifically, a current detection and protection circuit of a direct current motor is started along with a motor driving system, the current of the motor is sampled in real time through a precise sampling resistor, and after passing through a current detection circuit, the current passes through a current limiting protection circuit and is fed back to the motor driving system to realize current limiting protection; after the current is filtered and amplified by the high-precision operational amplifier circuit, the current is fed back to the motor driving circuit to realize the detection of the current.
The precision sampling resistor is formed by connecting two direct-insert sheet resistors with the resistance value of 0.01 omega, the power of 1W and the precision of +/-0.5% in parallel, one end of the precision sampling resistor is connected with the motor in series and is grounded, and the other end of the precision sampling resistor is connected with a current detection and protection circuit.
The current detection and protection circuit is formed by combining a rail-to-rail circuit, a high output current circuit, a two-way operational amplifier TS922 and resistors R3-R9, so that the operational amplification of the first-level large multiple of the sampling current and the current-limiting protection of the motor current are realized, wherein the R3 resistorThe value can be selected to be 4.7 Komega, the resistance value of R4 can be selected to be 10 Komega, one end of R3 is grounded after being connected with R4 in parallel, the other end of R5 is directly connected with the pin 2, R5 is an adjustable resistor, the first-stage operational amplification factor of the sampling current is adjustable, and the primary sampling voltage V is obtained through calculation1The output of the high-precision operational amplifier circuit is connected to the output of the high-precision operational amplifier circuit and then connected to the high-precision operational amplifier circuit; r6 and R7 in the current detection and protection circuit are adjustable resistors, so that the threshold voltage obtained by the pin 5 is adjustable when V is less than V1When the voltage value is less than or equal to the threshold voltage value of the pin 5, the pin 7 outputs a high level; when V is1When the voltage value is larger than the threshold voltage value of the pin 5, the pin 7 outputs low level, the motor is disabled, and current-limiting protection is realized.
The high-precision operational amplifier circuit is formed by combining an ultra-low power operational amplifier LT1494 with high-precision specification indexes, resistors R14, R16, R17, R18 and R20, capacitors C6 and C7, wherein the resistance value of R18 can be 5K omega, the resistance value of R20 can be 10K omega, the resistance value of R16 can be 10K omega, and R17 is an adjustable resistor, so that V can be regulated by the aid of the adjustable resistor1The secondary accurate adjustment amplification can be carried out according to actual needs, and the amplified signal is output to a motor drive control circuit after being filtered, so that accurate detection of the current is completed.
According to the above technical scheme, the utility model provides a pair of direct current motor's current detection and protection circuit, real-time detection direct current motor's operating current to can be according to actual load's demand, adjustment detection current amplification and current-limiting protection current-limiting threshold value optimize and make the motor setting at the most reasonable operating condition, reduce the power consumption, prevent motor overload operation, avoid motor and other equipment to damage.
Drawings
Fig. 1 is a design diagram of the whole scheme of the present invention.
Fig. 2 is a schematic diagram of a current detection and protection circuit.
FIG. 3 is a schematic diagram of a high-precision operational amplifier circuit.
Detailed Description
In order to clearly illustrate the technical means, main features and effects of the present invention, the following will further illustrate the embodiments of the present invention with reference to the accompanying drawings.
The utility model discloses an overall scheme design is shown in fig. 1, a current detection and protection circuit of a direct current motor is started along with a motor driving system, the motor current is sampled in real time through a precise sampling resistor, and after passing through a current detection circuit, the current passes through a current-limiting protection circuit and is fed back to the motor driving system to realize current-limiting protection; after the current is filtered and amplified by the high-precision operational amplifier circuit, the current is fed back to the motor driving circuit to realize the detection of the current.
Specifically, a schematic diagram of the current detection and protection circuit is shown in fig. 2, wherein R5 is an adjustable resistor, so that the first-stage operational amplification factor of the sampling current is adjustable, and the once-sampling voltage V is obtained by calculation1(ii) a R6 and R7 in the current detection and protection circuit are adjustable resistors, so that the threshold voltage obtained by the pin 5 is adjustable when V is less than V1When the voltage value is less than or equal to the threshold voltage value of the pin 5, the pin 7 outputs a high level; when V is1When the voltage value is larger than the threshold voltage value of the pin 5, the pin 7 outputs low level, the motor is disabled, and current-limiting protection is realized.
Specifically, a schematic diagram of a high-precision operational amplifier circuit is shown in fig. 3, wherein R17 is an adjustable resistor, so that V is a resistance of the adjustable resistor1The secondary accurate adjustment amplification can be carried out according to actual needs, and the current is output after filtering, so that accurate detection of the current is completed.
The following is a specific embodiment of the present invention, in which R5 is set to 124K Ω, R6 is set to 27.4K Ω, R7 is set to 13.3K Ω, and R17 is set to 20K Ω.
The real-time current of the motor after the motor runs with a load is I, and the voltage obtained by sampling through a precision sampling resistor is 0.01/2 multiplied by I; in the current detection and protection circuit, the parallel resistance of R3 and R4 is set as R34Then amplify the voltage V once1＝0.01/2×I×(1+R5/R34) 0.19875 × I, the threshold voltage of pin 5 is 5/(R6+ R7) × R7 is 1.634(V), and the overload protection current threshold is 1.634/0.19875 ≈ 8.22(a), that is, when the motor operating current exceeds 8.22A, the current limit level is low, and the motor current limit protection is turned on; in the high-precision operational amplifier circuit, when the quadratic amplification factor is R20/(R18+ R20) × (R16+ R17)/R16 is 2, the final output voltage is V1×2＝0.3975×I。
The basic principles and main features of the invention and the advantages of the invention have been shown and described above. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the foregoing embodiments and descriptions are provided only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (3)
1. The utility model provides a current detection and protection circuit of direct current motor which characterized in that: the high-precision sampling resistor is formed by connecting two direct-insert sheet resistors with the resistance value of 0.01 omega, the power of 1W and the precision of +/-0.5% in parallel, one end of the high-precision sampling resistor is connected with a motor in series and grounded, and the other end of the high-precision sampling resistor is connected with the current detection and protection circuit; the current detection and protection circuit is formed by combining a rail-to-rail, a high-output current, a two-way operational amplifier TS922 and resistors R3-R9, wherein one end of R3 is connected with R4 in parallel, the other end of the R3 is directly connected with R5 and a pin 2, R5 is an adjustable resistor, voltage amplification output is connected with a high-precision operational amplification circuit, R6 and R7 are adjustable resistors, so that the threshold voltage obtained by a pin 5 is adjustable, and a pin 7 is controlled to output a level signal to a motor drive control circuit to realize current limiting protection; the high-precision operational amplification circuit is formed by combining an ultra-low power operational amplifier LT1494 with high-precision specification indexes, resistors R14, R16, R17, R18 and R20, capacitors C6 and C7, wherein R17 is an adjustable resistor, and the adjustable resistor is filtered and then output to a motor drive control circuit to finish accurate detection of the current.
2. The current detection and protection circuit of a dc motor according to claim 1, wherein: the resistance value of R3 in the current detection and protection circuit can be selected to be 4.7K omega, and the resistance value of R4 can be selected to be 10K omega.
3. The current detection and protection circuit of a dc motor according to claim 1, wherein: the R18 resistance value in the high-precision operational amplification circuit can be 5K omega, the R20 resistance value can be 10K omega, and the R16 resistance value can be 10K omega.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921273128.XU CN210803671U (en) | 2019-08-08 | 2019-08-08 | Current detection and protection circuit of direct current motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921273128.XU CN210803671U (en) | 2019-08-08 | 2019-08-08 | Current detection and protection circuit of direct current motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210803671U true CN210803671U (en) | 2020-06-19 |
Family
ID=71229422
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921273128.XU Active CN210803671U (en) | 2019-08-08 | 2019-08-08 | Current detection and protection circuit of direct current motor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210803671U (en) |
-
2019
- 2019-08-08 CN CN201921273128.XU patent/CN210803671U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106646248A (en) | BMS current detection and overcurrent protection circuit | |
| CN205015401U (en) | Electric automobile insulation resistance detection circuitry | |
| CN218614063U (en) | Force sensing electric clamping jaw driving circuit | |
| CN210803671U (en) | Current detection and protection circuit of direct current motor | |
| CN104374983A (en) | Current monitoring circuit | |
| CN116191348A (en) | Current sampling and overcurrent protection circuit, system and method based on negative feedback adjustment | |
| CN110134168B (en) | Engine power compensation system of air automobile | |
| CN106019945A (en) | Flywheel battery-used axial magnetic bearing anti-disturbance controller construction method | |
| CN203422416U (en) | High-end current detection circuit | |
| CN103913597B (en) | A kind of gyroaccelerometer float centering monitoring system | |
| CN106374742B (en) | Switching Power Supply output frequency adjusts circuit | |
| CN204993259U (en) | Servovalve amplifier | |
| CN213544659U (en) | Non-isolated direct current bus voltage detection circuit | |
| CN202978837U (en) | Differential motion ratio amplifying circuit | |
| CN205537689U (en) | Foil gage zero setting circuit | |
| CN113363951B (en) | Direct current residual current protector, protection method and direct current power supply system | |
| CN104748877B (en) | The linear signal Acquisition Circuit and its system of a kind of temperature sensor | |
| CN102969991A (en) | Low-offset automatic compensation circuit | |
| CN105119579B (en) | Servo valve amplifier | |
| CN102944744A (en) | Low-drift online impedance measurement circuit | |
| CN106292825B (en) | A kind of precision current source control circuit that dependent sensor is hindered suitable for grounding type | |
| CN209725379U (en) | For matching and being converted into the signal adapter of electrohydraulic servo valve operating current signal | |
| CN113740087A (en) | Elevator balance coefficient detection equipment | |
| CN207067832U (en) | A kind of bipolar current source | |
| CN101825659B (en) | Electric quantity signal online detecting method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |