1 P/00/009A Section 29 AUSTRALIA Patents Act 1990 INNOVATION PATENT SPECIFICATION Invention Title: DISCHARGING CIRCUIT FOR CONTROLLING SPEED OF BRUSHED DC TUBULAR MOTOR AND CONTROL CIRCUIT THEREOF Applicant: Hangzhou Shtech Co., Ltd The invention is described in the following statement: 7019 2 Discharge Loop for Controlling Speed of Brushed DC Tubular Motor and Control Circuit Thereof 5 This application is a divisional of PCT/CN2010/076599 filed on 3 September 2010, the contents of which are to be taken as incorporated herein by this reference. Technical Field: The invention generally relates to a discharge loop for controllin; the speed of a 10 brushed Direct Current tubular motor and a speed control circuit formed therefrom, which are mainly used to realize a smooth and steady decline of an object which is suspended on the brushed direct current tubular motor, the invention belongs to the man facturing field of control circuits for the brushed direct current tubular motor. 15 Background Art At present, the brushed direct current tubular motor in the pric-r art operates in accordance with output power characteristic when being used for lifting or hoisting an object. Although the object is quite steady in the lifting process, it cannot realize a uniform and steady decline in the declining process when the object drags the motor owing to the 20 accelerating decline of the object based on the characteristics of the brushed direct current tubular motor. For example, when the brushed direct current tubular motor is used for a shutter door, some danger occur inevitably since the shutter door declines in an accelerating manner while dragging the brushed direct current tubular motor. Therefore, the traditional brushed direct current tubular motors can only generate an output torque in a small range, for 25 example, the brushed direct current tubular motor with the diameter of 45mm has only 8Nm torque, so the brushed direct current tubular motor cannot be applied wit lin a large torque output range. Summary of the invention 30 Design objective: in order to prevent the deficiencies in the prior art, the invention provides a discharge loop for controlling the speed of a brushed direct current tubular motor and a speed control circuit formed therefrom, which can achieve a smooth and steady decline of the object when it is suspended on the brushed direct current tubular mot:>r. Design scheme: in order to reach the above design objective, the present invention 35 provides a control circuit, which can not only realize normal up-and-doNn control of the brushed direct current tubular motor, but also realize ultra-large torque con rol of the brushed direct current tubular motor, thus the acceleration problem of the brushed direct current C \poftwordSPEC-938307 doc 3 tubular motor in the declining process in the case of large load is effectively solved and uniform and stable decline is maintained. The brushed direct current tubular motor generates different moments in the processes of lifting and declining an object, a moment in the same direction with the rotation 5 of the motor is generated in the process of lifting the object, while a moment in the direction opposite to the rotation of the motor, i.e. a brake moment is generated in the process of declining the object, and this brake moment is equal to the moment generated by the object under the action of gravity, so the resultant moment is zero which realizes a uniform decline of the object. When the moment generated by the object under the action of gravity is larger 10 than the brake moment generated by the brushed direct current tubular motor, the brushed direct current tubular motor is in the discharge state, and the object will create accelerated speed in the declining process, thus the speed becomes progressively faster. In order to control the speed of the brushed direct current tubular motor and keep uniform and stable operation of the motor, a resistor (a discharge resistor) is conrected in series in 15 the control circuit for the brushed direct current tubular motor to form the discharge loop. When the object is lifted by the brushed direct current tubular motor, the discharge loop is disconnected; when the object is declined by the brushed direct current ubular motor, the discharge loop is disconnected if the moment generated by the object under the action of gravity is still smaller than the maximal brake moment generated by the brushed direct 20 current tubular motor; if the moment generated by the object under the Ection of gravity is larger than the maximal brake moment generated by the brushed direct current tubular motor, the discharge loop starts operating to increase the brake moment, and the rioment generated under the action of gravity and the brake moment generated by the brushed direct current tubular motor are kept in balance, thus the brushed direct current tubular motor declines 25 uniformly and steadily. Technical solution 1: A method for controlling the speed of a brushed direct current tubular motor, the signal sampled by the sampling circuit from the brushed direct current tubular motor is amplified by the amplification circuit and then follows through thD voltage follower circuit to control the discharge loop to work or not, thus the brushed direct current tubular 30 motor is controlled to decline uniforinly and steadily. When the object is lifted by the motor, the discharge loop is disconnected; when the object is declined by the mctor, the discharge loop is disconnected if the moment generated by the object under the action of gravity is still smaller than the maximal brake moment generated by the motor; if the morient generated by the object under the action of gravity is larger than the maximal brake moment generated by 35 the motor, the discharge loop starts operating to increase the brake moment , and the moment generated under the action of gravity and the brake moment generated by :he brushed direct current tubular motor are kept in balance, thus the brushed direct current tubular motor C pof\word\SPEC-93807doc 4 declines uniformly and steadily. Technical solution 2: A discharge loop for controlling the speed of a bruE hed direct current tubular motor, which comprises a control circuit for the brushed direct current tubular motor, characterized in that, a resistor is connected in series between the outpu: end of a control 5 loop of the control circuit for the brushed direct current tubular motor and the cathode of a power supply to form the discharge loop when the motor generates power. The discharge loop is composed of resistors R1 and R2, capacitor C5 and a triode Q1, the collector of Q1 is connected with one end of R2, the anode of C5, the anode of a direct current power supply as well as one end of R5 in a sampling circuit, the other end of R2 is connected with the cathode 10 of C5, one end of R1 as well as the cathode of the direct current power supply, and the other end of R1 is connected with the emitter of Q1. Technical solution 3: A speed control circuit configured by the discharge loop for a brushed direct current tubular motor, comprising the brushed direct current tubular motor, a signal sampled by the sampling circuit from the brushed direct current tubular motor is 15 transmitted to the input end of an amplification circuit, the signal output end of the amplification circuit is connected with the signal input end of a voltage follower circuit, the signal output end of the voltage follower circuit is connected with the signal input end of the discharge loop, and the signal output end of the discharge loop is connectec with the brushed direct current tubular motor. The sampling circuit is composed of resistors R3, R4, R5 and R6, 20 diodes D4 and D5 and a rectifier bridge D1, the junction point of the resistors R3 and R4 is connected with one end of a resistor R7 in the amplification circuit, the jurction point of the resistors R5 and R6 is connected with one end of a resistor R9 in the amplification circuit, and the junction point of the resistors R4 and R6 is connected with the ground in parallel. Compared with the background art, the present invention has the follcwing advantages 25 that: 1. the brushed direct current tubular motor of the present invention can ascend and decline uniformly and steadily when being used for lifting and declining the object in a high torque output range, while the traditional brushed direct current tubular motor can only output a low torque in a small range; and 2), the circuit has the advantages of novel design, simplicity, reliability and good control effect, for example, the control torque of the brushed 30 direct current tubular motor with the diameter of 45mm can be up to 50Nm after the technical solution of this application is adopted, so an unexpected technical effect is achieved. Brief Description of the Drawings FIG.1 is a schematic diagram of a discharge loop for controlling ihe speed of the 35 brushed direct current tubular motor configured by a Darlington transistor. FIG.2 is a schematic diagram of a discharge loop for controlling Ihe speed of the brushed direct current tubular motor configured by a relay. C:,pol11dSPEC-9IN307doc 5 FIG.3 is a schematic block diagram of a speed control circuit for the brushed direct current tubular motor configured by the discharge loop. FIG.4 is a principle diagram of a speed control circuit for the speEd of the brushed direct current tubular motor configured by the discharge loop. 5 FIG.5 is an application schematic diagram of the speed control circLiit for the brushed direct current tubular motor. Detailed Description of the Embodiments Example 1: Refer to attached figure 1. A discharge loop for controlling the speed of a 10 brushed direct current tubular motor, comprising a control circuit for the brushed direct current tubular motor, a resistor is connected in series between the output end of a control loop of the control circuit for the brushed direct current tubular motor and the cathode of a power supply to form the discharge loop when the motor generates power. The discharge loop is composed of resistors R1 and R2, capacitor C5 and a triode Q1, the collector of Q1 s connected with 15 one end of R2, the anode of C5, the anode of a direct current power supply as well as one end of R5 in a sampling circuit, the other end of R2 is connected with the cathode of C5, one end of R1 as well as the cathode of the direct current power supply, and the other end of R1 is connected with the emitter of Q1. The triode Q1 is a Darlington transistor. Example 2: refer to Fig.2 which is based on the Example 1. The discharge loop during 20 power generation of the motor is configured by connecting a resistor between the output terminal of a relay and the cathode of the power supply. Example 3: Refer to attached figure 3 and 4. A speed control circuit ;onfigured by the discharge loop for a brushed direct current tubular motor, comprising the brushed direct current tubular motor, a signal sampled by the sampling circuit from the brusied direct current 25 tubular motor is transmitted to the input end of an amplification circuit (two ends of the motor are connected with one sampling circuit in parallel), the signal output end of the amplification circuit is connected with the signal input end of a voltage follower circuit, the signal output end of the voltage follower circuit is connected with the signal input end of the discharge loop, and the signal output end of the discharge loop is connected with the brushed direct current 30 tubular motor. The sampling circuit is composed of resistors R3, R4, R5 arid R6, diodes D4 and D5 and a rectifier bridge D1, the junction point of the resistors R3 and R4 is connected with one end of a resistor R7 in the amplification circuit, the junction point of the resistors R5 and R6 is connected with one end of a resistor R9 in the amplification circuit, and the junction point of the resistors R4 and R6 is connected with the ground in parallel. The amplification 35 circuit is composed of resistors R7, R8, R9 and R10 and an operational amplifier Al (LM358), one end of the resistor R7 is connected with the junction point of the resitors R3 and R4, while the other end is connected with the pin 2 of the operational amplifier Al and one end of C pofword\SPEC-938307doc 6 the resistor R8, the other end of R8 is connected with the pin 1 of the opera ional amplifier Al and the pin 5 of a operational amplifier A2 (LM358) in the voltage followed circuit, the other end of R9 is connected with one end of R10 and the pin 3 of Al, and the ol her end of R10 is grounded. The voltage follower circuit is composed of the operational amplifier A2, and the 5 pin 6 and the pin 7 of A2 are connected with the base of the triode in the discharge loop. Shown as Fig. 5, in the operating process of the motor, the motor rotates forward to drag the object upwards and rotates reversely to make the object decline downward. Shown as FIG.4, a voltage at the power input end AB of the brushed direct curren: tubular motor is sampled by a controller, the voltage at the point a after the division of the re 3istors R3 and R4 10 is input to the pin 2 of the operational amplifier Al, and the voltage sampled at two ends of the brushed direct current tubular motor is rectified by the rectifier bridge D1, the voltage at the point b after the division of the resistors R5 and R6 is input to the pin 3 of the operational amplifier Al. The resistors R7, R8, R9 and R10 and the operational amplifier Al form a differential amplification circuit, the operational amplifier A2 forms a vcltage follower. In 15 addition, R2, C5, Q1 and R1 form the discharge loop when the motor generates power, and the generated power is consumed by the resistor R1. When the brushed direct current tubular motor rotates forward to drag the object upwards, owing to the absence of a discharge state, a voltage difference is. present between the voltage at the input end of a sampling point and the voltages at two ends of the brushed 20 direct current tubular motor, thus resulting in a voltage difference between the voltage at the point a and the voltage at the point b. Since the voltage at the point a is higher than the voltage at the point b, the operational amplifier Al outputs a low level voltage which is input to Q1 via the voltage follower, thus Q1 is turned off which cause the discharge loop to be out of operation; 25 When the brushed direct current tubular motor declines together with an object, if the load is quite light, the moment generated by the object under the action of gravity is smaller than the brake moment generated by the brushed direct current tubular motor, in this case, the brushed direct current tubular is still not in the discharge state, the voltage at the point a is still higher than the voltage at the point b, the operational amplifier Al outputs a low level 30 voltage which is input to Q1 via the voltage follower, thus Q1 is turned off which also cause the discharge loop to be out of operation; When the brushed direct current tubular motor declines together with an object , if the load is quite heavy, the moment generated by the object under the action >f gravity is larger than the brake moment generated by the brushed direct current tubular motor, the motor 35 operates in a discharge state, in this case, the voltage at two ends of the brushed- direct current tubular motor is higher than the voltage at the power input end of he brushed direct current tubular motor, and after the voltages sampled at these two positiors were divided by C \poftwordtSPEC-938307doc 7 the resistor, the voltage at the point b is higher than the voltage at the point a, the operational amplifier Al outputs a high level voltage, which is input to Q1 via the voltage follower, thus Q1 is turned on which causes the discharge loop to start operating, which means the discharge machine carries loads, so that motor speed decreases. After the motor speed decreases, the 5 voltage at two ends of the brushed direct current tubular motor decreases as well. When the voltage at two ends of the brushed direct current tubular motor decreases until to be balance with the voltage at the input end, the operational amplifier Al outputs a low level voltage which makes Q1 turn off, so the discharge loop is disconnected. As the object declines, the discharge loop operates in a periodical way, as a result, a uniform and steady decline of the 10 brushed direct current tubular motor can be maintained. Example 5: according to the example 1-4, a method for controlling the speed of a brushed direct current tubular motor, characterized in that, the signal sampled by the sampling circuit from the brushed direct current tubular motor is amplified bV the amplification circuit and then follows through the voltage follower circuit to control the discharge loop to 15 operate or not, thus the brushed direct current tubular motor is controlled tc. decline uniformly and steadily. When an object is lifted by the motor, the discharge loop is disconnected; when the object is declined by the motor, the discharge loop is disconnected if the moment generated by the object under the action of gravity is still smaller than the maxir-ral brake moment 20 generated by the motor; if the moment generated by the object under the action of gravity is larger than the maximal brake moment generated by the motor, the discharge loop starts operating to increase the brake moment, and the moment generated under the action of gravity and the brake moment generated by the motor are kept in balance, thus the motor declines uniformly and steadily. 25 After a voltage is sampled at the power input end AB of the brushed direct current tubular motor and divided by the resistors R3 and R4, the voltage at the joint poin: a of the resistors R3 and R4 is input to the pin 2 of the operational amplifier Al. The voltage sampled at two ends of the brushed direct current tubular motor is rectified by the rectifier bridge Dl, the voltage at the point b obtained by the division of the resistors R5 and R6 is input to the pin 3 30 of the operational amplifier Al. Through the differential amplification circuit and a voltage follower, the power generated by the discharge loop is consumed by the resistor R1. When the brushed direct current tubular motor rotates forward to drag the object upwards, a voltage difference is present between the voltage at the input end of a sampling point and the voltages at two ends of the brushed direct current tubular motor, thus resulting 35 in a voltage difference between the voltage at the point a and the voltage at the point b. When the voltage at the point a is higher than the voltage at the point b, the operational amplifier Al outputs a low level voltage which is input to Ql via the voltage follower, thus Ql is turned off C:pofword\SPEC-93830Tdc 8 which cause the discharge loop to be out of operation; When the brushed direct current tubular motor declines together with an object, if the load is quite light, the moment generated by the object under the action of gravity is smaller than the brake moment generated by the brushed direct current tubular motor, the brushed 5 direct current tubular is still not in the discharge state. In this case, the voltage at the point a is still higher than the voltage at the point b, the operational amplifier Al outputs a low level voltage which is input to Q1 via the voltage follower, thus Q1 is turned off which also causes the discharge loop to be out of operation; When the brushed direct current tubular motor declines together with an object , if the 10 load is quite heavy, the moment generated by the object under the action cf gravity is larger than the brake moment generated by the brushed direct current tubular m tor, the brushed direct current tubular motor operates in a discharge state. In this case, the voltage at two ends of the brushed direct current tubular motor is higher than the voltage at the power input end of the brushed direct current tubular motor. After the voltages sampled at these two 15 positions were divided by the resistor, the voltage at the point b is higher than the voltage at the point a, the operational amplifier Al outputs a high level voltage, which 's input to Q1 via the voltage follower, thus Q1 is turned on which causes the discharge loop to start operating, which means the discharge machine carries loads, so that the speed of the brushed direct current tubular motor decreases. After the speed of the brushed direct current tubular motor 20 decreases, the voltage at two ends of the brushed direct current tubular motor decreases as well. When the voltage at two ends of the brushed direct current tubular motc r decreases until to be balance with the voltage at the input end, the operational amplifier Al outputs a low level voltage which makes Q1 turn off, so the discharge loop is disconnected. As the object declines, the discharge loop operates in a periodical way, as a result, a uniform and steady 25 decline of the brushed direct current tubular motor can be maintained. It needs to be understood that: although the present invention is described in detail by above embodiments, however, such description is merely a simply descriptive, not limitative, to the design concept of the present invention, and any combination, addition or modification which do not go beyond the design concept of the present invention shall fail in the scope of 30 the present invention. C \polbod\SPEC-938307 doc