CN103412598A - Hall position signal current type transmission circuit of brushless DC (direct current) motor - Google Patents

Abstract

The invention discloses a Hall position signal current type transmission circuit of a brushless DC motor. The Hall position signal current type transmission circuit comprises two power modules, a Hall signal preceding stage processing module, a voltage and current signal conversion module and a signal isolation output module, wherein Hall signals are processed through the preceding stage processing module; the input of the voltage and current signal conversion module is an output of the Hall signal preceding stage processing module; the input of the signal isolation output module is the output of the voltage and current signal conversion module; isolation signal output signals are output voltage signals; and a control chip input interface can be directly accessed for signal processing. When the Hall position signal transmission circuit performs Hall signal long distance transmission, the Hall signals cannot be disturbed, the brushless motor is guaranteed to operate normally, the defect that the motor cannot operate normally due to the fact that a Hall interface circuit is disturbed frequently during long distance Hall signal transmission in the prior art is avoided, and accuracy and high anti-interference performance of signal transmission are realized.

Description

A kind of brshless DC motor hall sensor signal current conveying circuit

Technical field

The present invention relates to a kind of current conveying circuit, particularly relate to a kind of brshless DC motor hall sensor signal current conveying circuit.

Background technology

The application of brushless electric machine in industrial transmission at present is more and more extensive.Brushless electric machine generally all is equipped with hall position sensor, hall position sensor can detect the position of permanent magnet rotor with respect to the stator armature winding, thereby determine conducting order and the conduction angle of each power tube in driving circuit, thereby control the stator armature electric current, also just controlled the magnetic state of armature field, realize electronic commutation, guaranteed the normal operation of brushless electric machine.The Hall output signal is generally all the TTL signal, and signal amplitude is not more than 15V.And industrial environment forceful electric power signal now is many, environment is more severe, adds weather environment such as thunder and lightning etc., and these forceful electric power signals can be easy to weak electric signal is produced and disturbs, and hall signal also is easy to disturbed; Hall signal is in a single day disturbed, will send into rub-out signal to controller, causes the misoperation of motor maybe can't move.Interference phenomenon not obvious during general short-distance transmission hall signal, but while in a single day needing long Distance Transmission hall signal, interference phenomenon is just apparent in view, for example industrial some occasion need to be installed separately brushless electric machine and driver, this just needs long hall signal line, and driver will obtain reliable hall signal, just must consider the impact of disturbing, avoid the mistake commutation of software, thereby guarantee the normal operation of brushless electric machine.

Summary of the invention

While for the hall signal that overcomes the prior art existence, growing Distance Transmission, easily be disturbed and cause the abnormal defect of motor rotation, the present invention to propose a kind of brshless DC motor hall sensor signal current conveying circuit.During the long Distance Transmission of this transmission circuit, not disturbed by forceful electric power, the defect that has been subjected to external interference to cause motor not run well while having avoided transmission, and have low-power consumption, and stability is high, and circuit structure is simple, the advantage that reliability is strong.

The technical solution adopted for the present invention to solve the technical problems is: comprise for the power module I to Hall element and operational amplifier power supply, be used for the signal prime processing module that the hall signal of Hall element output is processed, for the voltage and current signal modular converter that the Voltage-output signal of signal prime processing module is carried out to conversion, be converted to voltage signal and realize the signal isolation output module that signal is isolated for the current signal by the output of voltage and current signal modular converter; For the power module II to the power supply of signal isolation output module output terminal; Described hall element output voltage Vi is connected to the ground of power module I by series resistor R1, resistance R 2; The dividing potential drop Ui of described resistance R 2 is connected to the in-phase input end of operational amplifier A 1 and operational amplifier A 2, and the inverting input of operational amplifier A 1 is connected to the ground of power module I by series resistor R3; The inverting input of operational amplifier A 1 is connected to the output terminal of operational amplifier A 1 by series resistor R4, the output terminal of operational amplifier A 1 is connected to the emitter of triode T by series resistor Rx, the inverting input of operational amplifier A 2 directly is connected to the emitter of triode T, the output terminal of operational amplifier A 2 is connected to the base stage of triode T by series resistor R5, the collector output signal of triode is the output current signal after conversion;

The input anode of described signal isolator spare P is connected to the collector of triode T, the input cathode of signal isolator spare P is connected to the ground of power module I, the output head anode of signal isolator spare P is connected to the anode of power module II by pull-up resistor R6, the negative pole of output end of signal isolator spare P directly is connected to the ground of power module II, and the output head anode of signal isolator spare P is drawn output voltage signal Vo;

The current signal io of described voltage and current signal modular converter output is directly proportional to input voltage Vi, current signal io and the resistance R x of the output of voltage and current signal modular converter are inversely proportional to, and output current io drives the output that rear class signal isolator spare P realizes voltage signal again.

Described power module I and described power module II are two independent isolating power supplys, can not be altogether.

Beneficial effect

A kind of brshless DC motor hall sensor signal current conveying circuit that the present invention proposes, it comprises two power modules, a hall signal prime processing module, a voltage and current signal modular converter and a signal isolation output module, wherein hall signal is processed by the prime processing module, the output that is input as hall signal prime processing module of voltage and current signal modular converter, the output that is input as the voltage and current signal modular converter of signal isolation output module, the isolation signals output signal is output voltage signal, directly Access Control chip input interface carries out the signal processing, long Distance Transmission brushless motor Hall signal is when being subject to extraneous forceful electric power interference, hall signal can be not disturbed, the defect of having avoided the hall interface circuit of prior art usually easily to cause motor to run well because of interference effect when the long-distance transmissions hall signal, realized the accuracy of signal transmission, strong anti-interference, the hall sensor signal current conveying circuit is simple in structure, and has low in energy consumptionly, and stability is high, the advantage that reliability is strong.

The accompanying drawing explanation

Below in conjunction with drawings and embodiments, a kind of brshless DC motor hall sensor signal of the present invention current conveying circuit is described in further detail.

Fig. 1 is brshless DC motor hall sensor signal current conveying circuit module diagram of the present invention.

Fig. 2 is brshless DC motor hall sensor signal current conveying circuit figure of the present invention.

Embodiment

The present embodiment is a kind of brshless DC motor hall sensor signal current conveying circuit.The present embodiment has only provided the wherein circuit of a road hall sensor signal, and other two-way is identical with this transmission circuit.

Consult Fig. 1, brshless DC motor hall sensor signal current conveying circuit of the present invention, comprise for the power module I to Hall element 3 and operational amplifier power supply; Be used for the signal prime processing module 4 that the hall signal of Hall element 3 outputs is processed; For the voltage and current signal modular converter 5 that the Voltage-output signal of signal prime processing module 4 is carried out to conversion; For the current signal by 5 outputs of voltage and current signal modular converter, be converted to voltage signal and realize the signal isolation output module 6 that signal is isolated; For the power module II to the 6 output terminal power supplies of signal isolation output module; Wherein, giving the power module I of Hall element and operational amplifier power supply and the power module II to the power supply of signal isolation output module output terminal is two independent isolating power supplys, can not be altogether.

As shown in Figure 2, function realizing circuit figure of the present invention is by operational amplifier A 1, operational amplifier A 2, signal isolator spare P, PNP triode T, the first resistance R 1, the second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R x forms, circuit obtains in the following way: hall element output voltage Vi is connected to the ground of power module 1 by series resistor R1 and resistance R 2, by the in-phase input end of the voltage division signal Ui of resistance R 2 by series resistor R3 access operational amplifier A, the inverting input of operational amplifier A 1 is connected to the ground of power module 1 by series resistor R3, the inverting input of operational amplifier A 1 is connected to the output terminal of operational amplifier A 1 by series resistor R4, the output terminal of operational amplifier A 1 is connected to the emitter of triode T by series resistor Rx, the inverting input of operational amplifier A 2 directly is connected to the emitter of triode T, the output terminal of operational amplifier A 2 is connected to the base stage of triode T by series resistor R5, the collector output signal of triode is the output current signal after conversion.The current signal io of voltage and current signal modular converter output is directly proportional to input voltage Vi, and current signal io and the resistance R x of the output of voltage and current signal modular converter are inversely proportional to.Output current io drives the output that rear class signal isolator spare P realizes voltage signal again.

The relational expression step is as follows:

Making the voltage on operational amplifier A 1 in-phase input end is U _P1, the voltage on operational amplifier A 1 inverting input is U _N1, the voltage on operational amplifier A 2 in-phase input ends is U _P2, the voltage on operational amplifier A 2 inverting inputs is U _N2, the voltage on operational amplifier A 1 output terminal is U1, and on triode T emitter, voltage is U2, and the hall signal voltage of input is V _i, the voltage on R1, R2 dividing potential drop R2 is U _i, the electric current on Rx is i, and long Distance Transmission electric current is io, and signal isolator spare output voltage is Vo.Input with the pass of output signal is:

$U_i=V_i\×\frac{R2}{R1+R2}$

U _p1=U _n1=U _i

$U1=U_i\×\frac{R3+R4}{R3}$

U _p2=U _n2=U2=U _i

$U1-U2=U_i\×\frac{R3+R4}{R3}-U_i=\frac{R4}{R3}{U}_i$

$i=\frac{U1-U2}{\mathrm{Rx}}=\frac{R4}{R3\mathrm{Rx}}{U}_i,$ When being in the amplification duty, the PNP triode has: $i_o=\frac{\mathrm{\β}}{1+\mathrm{\β}}i\≈i;$

∴ $i_o=\frac{U1-U2}{\mathrm{Rx}}=\frac{R4}{R3*\mathrm{Rx}}{U}_i=\frac{R4R2}{R3*\mathrm{Rx}(R1+R2)}\×V_i$

By giving brshless DC motor, hall device and transmission circuit are powered, when brshless DC motor turns round, directly the Hall voltage signal of brshless DC motor output is connected to the input end of circuit after on 15V, drawing, the Hall voltage signal is through the voltage division processing of front stage circuits, signal after processing is again sent into the electric current and voltage modular converter, now voltage signal becomes current signal according to the relationship conversion of deriving, after processing again signal transmit, now that current signal transmits, strong anti-interference due to current delivery, thereby can realize long Distance Transmission, again by current signal transfer to rear class signal isolation module, it after isolation module, is output voltage signal, thereby can directly send into controller and carry out the signal processing.

A kind of device preferred version of the present embodiment:

Signal isolator spare is selected optocoupler PC817, amplifier is selected LM358, the PNP triode is selected 2SB449, R1=4k Ω, R2=R3=R4=1k Ω, Rx=1.5k Ω, R5=100 Ω, Vi=15V, during motor rotation, the current signal that the Hall voltage signal of 15V just can be exchanged into io=20mA transmits, and has strengthened the anti-interference of signal.The current signal of 20mA also can drive rear class optocoupler PC817 normal operation simultaneously, makes the rear class output voltage signal, has played buffer action, has also realized the transmitting of signal simultaneously.

Conclusion: output current size and Hall voltage signal V _iSize is directly proportional, and the output current size is inversely proportional to resistance R x resistance, by selecting the resistance of resistance R 1, R2, R3, R4, Rx, control the size of transmission current, and then can, by Current Control in rational scope, realize current delivery, and the delay of signal be very little.

Claims (2)

1. brshless DC motor hall sensor signal current conveying circuit is characterized in that: comprise Hall element, power module I, signal prime processing module, voltage and current signal modular converter, signal isolation output module, power module II,

Described hall element output voltage Vi is connected to the ground of power module I by series resistor R1, resistance R 2;

The dividing potential drop Ui of described resistance R 2 is connected to the in-phase input end of operational amplifier A 1 and operational amplifier A 2, and the inverting input of operational amplifier A 1 is connected to the ground of power module I by series resistor R3; The inverting input of operational amplifier A 1 is connected to the output terminal of operational amplifier A 1 by series resistor R4, the output terminal of operational amplifier A 1 is connected to the emitter of triode T by series resistor Rx, the inverting input of operational amplifier A 2 directly is connected to the emitter of triode T, the output terminal of operational amplifier A 2 is connected to the base stage of triode T by series resistor R5, the collector output signal of triode is the output current signal after conversion;

The input anode of described signal isolator spare P is connected to the collector of triode T, the input cathode of signal isolator spare P is connected to the ground of power module I, the output head anode of signal isolator spare P is connected to the anode of power module II by pull-up resistor R6, the negative pole of output end of signal isolator spare P directly is connected to the ground of power module II, and the output head anode of signal isolator spare P is drawn output voltage signal Vo;

The current signal io of described voltage and current signal modular converter output is directly proportional to input voltage Vi, current signal io and the resistance R x of the output of voltage and current signal modular converter are inversely proportional to, and output current io drives the output that rear class signal isolator spare P realizes voltage signal again.

2. brshless DC motor hall sensor signal current conveying circuit according to claim 1, it is characterized in that: described power module I and described power module II are two independent isolating power supplys, can not be altogether.

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