CN201608517U - Motor overload protection circuit - Google Patents
Motor overload protection circuit Download PDFInfo
- Publication number
- CN201608517U CN201608517U CN2009202782968U CN200920278296U CN201608517U CN 201608517 U CN201608517 U CN 201608517U CN 2009202782968 U CN2009202782968 U CN 2009202782968U CN 200920278296 U CN200920278296 U CN 200920278296U CN 201608517 U CN201608517 U CN 201608517U
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- resistance
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- motor
- current
- operational amplifier
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- Control Of Electric Motors In General (AREA)
- Protection Of Generators And Motors (AREA)
Abstract
A motor overload protection circuit comprises a current sampling unit, a current signal processing unit and a voltage signal comparing unit, wherein the output end of the current sampling unit is connected with the input end of the current signal processing unit; the output end of the current signal processing unit is connected with the input end of the voltage signal comparing unit; the output end of the voltage signal comparing unit is connected with a controlled motor through a control computer; and the current sampling unit is arranged on a power supply line of the controlled motor. The motor overload protection circuit has the following advantages: when the controlled motor is in overload state, the control computer controls the motor to reduce speed till stop at fastest acceleration according to changes occurring on signal level, thus effectively avoiding the probable damages of power off to rotating mechanisms driven by the motor, or the motor.
Description
Technical field
The utility model relates to a kind of motor overload protection circuit, relate in particular to a kind of fast, can adjust the motor overload protection circuit of threshold value.
Background technology
Motor overload protection circuit commonly used at present is generally closed-loop control, when the motor overload, by the protection motor of cutting off the electricity supply automatically.Sometimes because need protection motor-driven rotating mechanism or motor itself; if when motor runs up, cut off the electricity supply; may cause damage to motor-driven rotating mechanism or motor, can only motor speed be reduced to by moderating process and stop, and prior art can't satisfy this requirement.
Summary of the invention
The utility model provides a kind of motor overload protection circuit that can be connected to the control computer; be intended to solve exist in the prior art when the motor overload; by the protection motor of cutting off the electricity supply automatically, may be to motor or the hurtful problem of motor-driven rotating mechanism.
The utility model is taked following technical scheme: comprise current sampling unit, current signal processing unit and voltage signal comparing unit, the output of current sampling unit is connected with the input of current signal processing unit, the output of this current signal processing unit is connected with the input of voltage signal comparing unit, and the output of this voltage signal comparing unit is connected with the Be Controlled motor by the control computer; Described current sampling unit is located in the supply line of this Be Controlled motor.
Described current sampling unit is a current sensor.
Described current signal processing unit comprises protective circuit, negative feedback amplifier circuit and the current rectifying and wave filtering circuit that connects successively, and this protective circuit is made of the opposite diode parallel connection of both direction; This negative feedback amplifier circuit comprises operational amplifier IC1 and the feedback resistance that is connected between its output and the negative input end constitutes, the negative input end of this operational amplifier IC1 is connected with the output of described current sensor, the positive input terminal ground connection of this operational amplifier IC1, the positive and negative input of this operational amplifier IC1 are connected with the two ends of the diode of described protective circuit respectively; This current rectifying and wave filtering circuit is made up of resistance R 1 and R2, diode D3 and capacitor C 1, be connected with an end of resistance R 2 and capacitor C 1 behind resistance R 1 and the diode D3 of the output of described operational amplifier IC1 by series connection, this link is as the output of this current signal processing unit, the other end ground connection of this resistance R 2 and capacitor C 1.
Described voltage signal comparing unit is made up of operational amplifier IC2, potentiometer VR1 and resistance R 3, the end of potentiometer VR1 is connected to positive source, another termination power cathode or ground connection of this potentiometer VR1, the centre tap of this potentiometer VR1 passes through resistance R 3 or directly is connected with the input of computing operational amplifier IC2, and another input of this computing operational amplifier IC2 is connected with the output of described current signal processing unit.
Output at described voltage signal comparing unit connects a level finishing circuit, this level finishing circuit comprises resistance R 4, R5, R6, diode D4 and voltage stabilizing didoe ZD1, resistance R 4 is connected with the end of resistance R 5, R6 with diode D4 series connection back, the other end of this resistance R 5, R6 is connected with negative pole with the positive pole of voltage stabilizing didoe ZD1 respectively, the negative pole of this voltage stabilizing didoe ZD1 is as the output of this level finishing circuit, and be connected the plus earth of this voltage stabilizing didoe ZD1 with described control computer.
The utility model has the advantages that: current sensor obtains corresponding current signal from supply line's up-sampling of Be Controlled motor, amplify and be converted to d. c. voltage signal through the overcurrent signal processing unit, and with d. c. voltage signal and reference voltage relatively by the voltage signal comparing unit, export the signal of corresponding high or low level, and output to the control computer, when the Be Controlled motor overload, the variation control motor that the control computer occurs according to the level of signal decelerates to the fastest acceleration and stops.The infringement of having avoided effectively cutting off the electricity supply and to have caused motor-driven rotating mechanism or motor.
Description of drawings
Fig. 1 is an overall circuit block diagram of the present utility model;
Fig. 2 is the circuit theory diagrams of the utility model embodiment.
Embodiment
Referring to Fig. 1, the utility model comprises current sampling unit 1, current signal processing unit 2, voltage signal comparing unit 3 and control computer 4, the output of current sampling unit 1 is connected with the input of current signal processing unit 2, the output of this current signal processing unit 2 is connected with the input of voltage signal comparing unit 3, and the output of this voltage signal comparing unit 3 is connected with Be Controlled motor 5 by control computer 4.Current sampling unit 1 is current sensor S1 (referring to Fig. 2), and this current sensor S1 is located at from the supply line of Be Controlled motor 5, obtains current signal from this supply line's sampling.The current signal processing unit 2 just current signal that obtains of current sensor sampling amplifies and is converted to d. c. voltage signal.Voltage signal comparing unit 3 amplifies the d. c. voltage signal that is converted to and reference voltage relatively, with the voltage of reference signal just not simultaneously, output signal level difference (high or low).The level signal of output is connected to control computer 4, and when Be Controlled motor 5 overload, variation control motor that control computer 4 occurs according to the level of signal 5 decelerates to the fastest acceleration and stops.Adopt conventional connected mode (controlling) between control computer 4 and the motor 5 by 6 pairs of motors 5 of electric machine controller.
Referring to Fig. 2, current sensor S1 adopts 1/2000 mutual inductance type current sensor, and the electric current of output is 1/2000 of a motor supply current.Current phase no requirement (NR) to current sensor S1.
The current rectifying and wave filtering circuit that current signal processing unit 2 is formed by integrated operational amplifier IC1, feedback resistance Rf, protection diode D1 and D2, by R1, R2, D3, C1 is formed.D1, D2 are the opposite diode of both direction, are connected the positive-negative input end of operational amplifier IC1, with protection IC1.Operational amplifier IC1 selects getting final product of general performance.The resistance of feedback resistance Rf can be determined according to actual needs, and output voltage V out=Rf*Iin, Iin are the output current of current sensor S1.The voltage of operational amplifier IC1 output is AC signal, advances the current rectifying and wave filtering circuit dress that resistance R 1, R2, diode D3, capacitor C 1 form and is changed to direct voltage, and therefore direct voltage direct ratio and alternating voltage also are proportional to the supply current of Be Controlled motor 5.The numerical value of R1, C1 can determine as required that R1*C1 is protection start-up time, and the big more protective circuit reaction of this value is slow more, and the more little protective circuit reaction of this value is fast more.
Voltage signal comparing unit 3 is by operational amplifier IC2 and provide the circuit (comprising potentiometer VR1, resistance R 3) of reference voltage to form.Operational amplifier IC2 selects getting final product of general performance.The two ends of potentiometer VR1 are connected respectively to positive supply feeder ear and negative supply feeder ear (or ground), and the centre tap output reference voltage is received the input of computing operational amplifier IC2 by resistance R 3 (or directly).Positive and negative input (or the negative, positive input that the direct voltage of current signal processing unit 2 outputs and reference voltage (end of resistance R 3) are connected on operational amplifier IC2 respectively, below analyzing to be input to positive and negative input is example), the level of operational amplifier IC2 output has reacted the direct voltage of current signal processing unit 2 outputs and the magnitude relationship of reference voltage.When 5 loads of Be Controlled motor increased, supply current also increased, and the direct voltage of corresponding current signal processing unit 2 outputs also increases, and when this voltage surpassed reference voltage, the level of operational amplifier IC2 output was by the low height that transfers to.Resistance R 4, R5 and diode D4, ZD1 put the level signal of operational amplifier IC2 output in order level level that control computer 4 can be accepted, and are transported to this control computer 4.
Claims (5)
1. motor overload protection circuit, it is characterized in that: comprise current sampling unit, current signal processing unit and voltage signal comparing unit, the output of current sampling unit is connected with the input of current signal processing unit, the output of this current signal processing unit is connected with the input of voltage signal comparing unit, and the output of this voltage signal comparing unit is connected with the Be Controlled motor by the control computer; Described current sampling unit is located in the supply line of this Be Controlled motor.
2. motor overload protection circuit according to claim 1 is characterized in that: described current sampling unit is a current sensor.
3. motor overload protection circuit according to claim 2, it is characterized in that: described current signal processing unit comprises protective circuit, negative feedback amplifier circuit and the current rectifying and wave filtering circuit that connects successively, and this protective circuit is made of the opposite diode parallel connection of both direction; This negative feedback amplifier circuit comprises operational amplifier (IC1) and the feedback resistance that is connected between its output and the negative input end constitutes, the negative input end of this operational amplifier (IC1) is connected with the output of described current sensor, the positive input terminal ground connection of this operational amplifier (IC1), the positive and negative input of this operational amplifier (IC1) are connected with the two ends of the diode of described protective circuit respectively; This current rectifying and wave filtering circuit is made up of resistance (R1, R2), diode (D3) and electric capacity (C1), the output of described operational amplifier (IC1) is connected with the end of resistance (R2) with electric capacity (C1) with diode (D3) back by the resistance (R1) of series connection, this link is as the output of this current signal processing unit, the other end ground connection of this resistance (R2) and electric capacity (C1).
4. motor overload protection circuit according to claim 1; it is characterized in that: described voltage signal comparing unit is by operational amplifier (IC2); potentiometer (VR1) and resistance (R3) are formed; one end of potentiometer (VR1) is connected to positive source; another termination power cathode or ground connection of this potentiometer (VR1); the centre tap of this potentiometer (VR1) passes through resistance (R3) or directly is connected with an input of computing operational amplifier (IC2), and another input of this computing operational amplifier (IC2) is connected with the output of described current signal processing unit.
5. motor overload protection circuit according to claim 1; it is characterized in that: the output at described voltage signal comparing unit connects a level finishing circuit; this level finishing circuit comprises resistance (R4; R5; R6); diode (D4) and voltage stabilizing didoe (ZD1); resistance (R4) is connected with diode (D4) afterwards and resistance (R5; R6) a end connects; this resistance (R5; R6) the other end is connected with negative pole with the positive pole of voltage stabilizing didoe (ZD1) respectively; the negative pole of this voltage stabilizing didoe (ZD1) is as the output of this level finishing circuit; and be connected the plus earth of this voltage stabilizing didoe (ZD1) with described control computer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009202782968U CN201608517U (en) | 2009-12-29 | 2009-12-29 | Motor overload protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009202782968U CN201608517U (en) | 2009-12-29 | 2009-12-29 | Motor overload protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201608517U true CN201608517U (en) | 2010-10-13 |
Family
ID=42953218
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009202782968U Expired - Lifetime CN201608517U (en) | 2009-12-29 | 2009-12-29 | Motor overload protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201608517U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104834343A (en) * | 2015-04-02 | 2015-08-12 | 来安县新元机电设备设计有限公司 | Load protection circuit and device |
-
2009
- 2009-12-29 CN CN2009202782968U patent/CN201608517U/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104834343A (en) * | 2015-04-02 | 2015-08-12 | 来安县新元机电设备设计有限公司 | Load protection circuit and device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20101013 |
|
| CX01 | Expiry of patent term |