A dynamometer circuit and fitness bike

Abstract

The present invention discloses a dynamometer circuit, which is applied to a fitness bike, and the fitness bike includes a generator. In this scheme, when a fitness person uses the fitness bike, the riding process causes the generator to generate electricity, and the alternating current generated by the generator is converted into direct current through a rectifier module, and the processor determines the power value through the first voltage signal at both ends of the current sampling resistor and the second voltage signal at the first end of the first resistor. It can be seen that this method can determine the amount of work done by the fitness person when using the fitness bike by setting simple components in the circuit, which reduces the cost of the fitness bike and can truly realize the promotion of civilian products; and when the fitness person uses the fitness bike to ride, the processor calculates the average power value by detecting the current and voltage emitted by the generator, and the error is small compared with the actual work done by the fitness person, and the accuracy of measuring power in this way is high. The present invention also discloses a fitness bike, which has the same beneficial effects as the above-mentioned dynamometer circuit.

Description

Technical Field

[0001] The invention relates to the field of electronic circuits and fitness equipment, in particular to a dynamometer circuit and a fitness bike. Background Art

[0002] With the significant improvement of people's living standards and the enhancement of health awareness, more and more people are engaged in fitness exercises. Among them, exercise bikes are widely loved by fitness enthusiasts due to their simple exercise methods, obvious exercise effects and low exercise risks.

[0003] When a fitness person uses an exercise bike for training, he usually evaluates the training effect of the fitness person by the power value calculated by the exercise bike. In the prior art, there are two ways for various types of exercise bikes to obtain power values:

[0004] First, the torque sensor installed on the exercise bike collects torque and other data, and then processes the collected data through software algorithms to obtain power values. However, this method is too expensive. The cost of a torque sensor accounts for more than 50% of the entire exercise bike, and it is impossible to truly promote civilian products.

[0005] Second, the calories consumed by the fitness user are calculated based on the current speed, resistance level and weight of the fitness user, and the power value is calculated based on the calories consumed by the fitness user and the fitness time. However, the power value calculated by this method has a large error compared with the actual power. Summary of the invention

[0006] The purpose of the present invention is to provide a dynamometer circuit and an exercise bike, which can determine the amount of work done by a fitness person when using the exercise bike by setting simple components in the circuit, thereby reducing the cost of the exercise bike and truly realizing the promotion of civilian products; and when a fitness person rides the exercise bike, a processor calculates an average power value by detecting the current and voltage emitted by a generator, and the error is small compared with the actual work done by the fitness person, and the power measured in this way has high accuracy.

[0007] In order to solve the above technical problems, the present invention provides a dynamometer circuit, which is applied to a fitness bike, wherein the fitness bike also includes a generator, and the dynamometer circuit includes:

[0008] A rectifier module whose input end is connected to the output end of the generator and whose negative output end is grounded, and is used to convert the alternating current output by the generator into direct current;

[0009] A current sampling resistor connected in series to the output loop of the rectifier module;

[0010] A current detection module having a positive input terminal connected to the second terminal of the current sampling resistor module, a negative input terminal connected to the first terminal of the current sampling resistor module, and an output terminal connected to the input terminal of the processor, and used to detect a first voltage signal at both ends of the current sampling resistor;

[0011] A voltage dividing module having a first end connected to the positive output end of the rectifier module and a second end connected to the first end of the first resistor and the processor;

[0012] The first resistor having a second end grounded;

[0013] The processor is used to determine a current sampling value of the direct current flowing through the current sampling resistor based on the first voltage signal, determine a voltage sampling value based on a second voltage signal at the first end of the first resistor, and determine a power value based on the current sampling value and the voltage sampling value.

[0014] Preferably, the current detection module includes:

[0015] a first operational amplifier resistor whose first end is connected to the second end of the current sampling resistor and whose second end is grounded;

[0016] An operational amplifier having a positive input terminal connected to the first end of the first operational amplifier resistor, a negative input terminal connected to the first end of the current sampling resistor, and an output terminal connected to the second end of the second operational amplifier resistor and the input terminal of the processor, and used to amplify the first voltage signal;

[0017] The second operational amplifier resistor has a first end connected to the negative input terminal of the operational amplifier.

[0018] Preferably, it also includes:

[0019] A first current limiting filter module, the input end of which is connected to the second end of the current sampling resistor, and the output end of which is connected to the first end of the first operational amplifier resistor and the positive input end of the operational amplifier, for limiting the current flowing through the loop and filtering the voltage signal at the second end of the current sampling resistor;

[0020] and / or, a second current limiting filter module having an input end connected to the first end of the current sampling resistor and an output end connected to the negative input end of the amplification module and the first end of the second operational amplifier resistor, for limiting the current flowing through the loop and filtering the voltage signal at the first end of the current sampling resistor;

[0021] And / or, a first protection module having an input end connected to the output end of the operational amplifier and an output end connected to the input end of the processor, is used to filter the amplified first voltage signal.

[0022] Preferably, it also includes:

[0023] A limiting module, the first end of which is connected to the first end of the first resistor and the second end of which is connected to the input end of the voltage follower, for limiting the second voltage signal;

[0024] A voltage follower whose input end is connected to the second end of the limiting module and whose output end is connected to the input end of the second protection module, and is used to stabilize and isolate the second voltage signal after limiting;

[0025] And / or, the second protection module, whose output end is connected to the input end of the processor, is used to filter the second voltage signal after voltage stabilization and isolation.

[0026] Preferably, it also includes:

[0027] a speed detection module having an input end connected to the input end of the rectifier module and an output end connected to the processor, for generating a speed pulse signal based on the alternating current generated by the generator;

[0028] The processor is further used to determine whether the generator is in working state based on the speed pulse signal.

[0029] Preferably, the speed detection module comprises:

[0030] a diode having an anode connected to the input end of the rectifier module and a common end serving as the input end of the speed detection module and a cathode connected to the first end of the second resistor, for generating pulsed direct current based on the alternating current output by the generator;

[0031] the second resistor having a first end connected to the cathode of the diode and a second end grounded;

[0032] A first switch module having a control end connected to the first end of the second resistor, a first end connected to the processor, and a second end connected to ground, and configured to control itself to be closed or opened based on the pulsed direct current;

[0033] A pull-up resistor having a first end connected to the first power source and a second end connected to the first end of the first switch module and the processor.

[0034] Preferably, it also includes:

[0035] A filter module having a first end connected to the positive output end of the rectifier module and a second end connected to the second end of the current sampling resistor, and used for filtering the direct current output by the rectifier module;

[0036] The resistance adjustment module, whose first end is connected to the first end of the filter module and whose second end is connected to the second end of the filter module, is used for controlling the load to perform corresponding resistance adjustment after receiving a resistance adjustment instruction.

[0037] Preferably, the resistance adjustment module comprises:

[0038] A second switch module, the control end of which serves as the input end of the resistance adjustment module, the first end of which is connected to the first end of the load, and the second end of which is grounded, is used to control the magnitude of the current in the circuit based on the resistance adjustment instruction, so that the load performs corresponding resistance adjustment according to the magnitude of the current;

[0039] a third resistor having a first end connected to the control end of the second switch module and a second end connected to the ground;

[0040] A freewheeling module having a positive electrode connected to the first end of the second switch module and a negative electrode connected to the second end of the load and the first end of the filter module.

[0041] Preferably, the processor is also used to enter the steps of determining a current sampling value of the direct current flowing through the current sampling resistor based on the first voltage signal and determining a voltage sampling value based on a second voltage signal at the first end of the first resistor when it is determined that the generator is in a working state.

[0042] Preferably, determining the power value based on the current sampling value and the voltage sampling value includes:

[0043] Calculate the average current value based on the current sampling values ​​within the preset time, and calculate the average voltage value based on the voltage sampling values ​​within the preset time;

[0044] The power value is determined based on the average voltage value and the average current value.

[0045] In order to solve the above technical problems, the present invention further provides a fitness bike, comprising a generator and the dynamometer circuit as described above.

[0046] The present invention provides a dynamometer circuit, which is applied to a fitness bike, and the fitness bike also includes a generator. In this scheme, when a fitness person uses the fitness bike, the riding process causes the generator to generate electricity, and the alternating current generated by the generator is converted into direct current through a rectifier module, and the processor determines the power value through the first voltage signal at both ends of the current sampling resistor and the second voltage signal at the first end of the first resistor. It can be seen that this method can determine how much work the fitness person does when using the fitness bike by setting simple components in the circuit, which reduces the cost of the fitness bike and can truly realize the promotion of civilian products; and when the fitness person uses the fitness bike to ride, the processor calculates the average power value by detecting the current and voltage generated by the generator, and the error is small compared with the actual work done by the fitness person, and the accuracy of measuring power in this way is high.

[0047] The present invention also provides a fitness bike having the same beneficial effects as the above dynamometer circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0049] Figure 1 A circuit diagram of a dynamometer circuit provided by the present invention;

[0050] Figure 2 A process flow chart of a processor in a dynamometer circuit provided by the present invention;

[0051] Figure 3 A circuit diagram of another dynamometer circuit provided by the present invention. DETAILED DESCRIPTION

[0052] The core of the present invention is to provide a dynamometer circuit and an exercise bike, which can determine the amount of work done by a fitness person when using the exercise bike by setting simple components in the circuit, thereby reducing the cost of the exercise bike and truly realizing the promotion of civilian products; and when a fitness person rides the exercise bike, the processor calculates the average power value by detecting the current and voltage emitted by the generator, and the error is small compared with the actual work done by the fitness person, and the power measured in this way has high accuracy.

[0053] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] Please refer to Figure 1 and Figure 2 , Figure 1 A circuit diagram of a dynamometer circuit provided by the present invention, Figure 2 A process flow chart of a processor in a dynamometer circuit provided by the present invention.

[0055] The dynamometer circuit is applied to a fitness bike, which also includes a generator. The dynamometer circuit includes:

[0056] A rectifier module 1 whose input end is connected to the output end of the generator and whose output negative end is grounded, is used to convert the alternating current output by the generator into direct current;

[0057] A current sampling resistor 2 connected in series to the output circuit of the rectifier module 1;

[0058] A current detection module 3 having a positive input terminal connected to the second terminal of the current sampling resistor 2 module, a negative input terminal connected to the first terminal of the current sampling resistor 2 module, and an output terminal connected to the input terminal of the processor 5, for detecting a first voltage signal at both ends of the current sampling resistor 2;

[0059] A voltage dividing module 4 having a first end connected to the positive output end of the rectifier module 1 and a second end connected to the first end of the first resistor R1 and the processor 5;

[0060] A first resistor R1 with a second end grounded;

[0061] Processor 5, used to implement steps S21 and S22;

[0062] S21: determining a current sampling value of the direct current flowing through the current sampling resistor 2 based on the first voltage signal, and determining a voltage sampling value based on a second voltage signal at the first end of the first resistor R1;

[0063] S22: Determine a power value based on the current sampling value and the voltage sampling value.

[0064] The applicant considers that when a fitness person uses an exercise bike for training, the training effect of the fitness person is usually evaluated by the power value calculated by the exercise bike. In the prior art, various fitness bikes usually obtain power values ​​by collecting torque and other data through a torque sensor installed on the fitness bike, and then the collected data is processed by a software algorithm to obtain the power value or calculate the power value based on the current speed, resistance level and weight of the fitness person. However, the method of setting a torque sensor is too expensive. The cost of a torque sensor accounts for more than 50% of the entire fitness bike, and it is impossible to truly promote civilian products; and the power value calculated by the method of calculating the power value based on the current speed, resistance level and weight of the fitness person is too large compared with the actual power.

[0065] In this embodiment, a dynamometer circuit is provided inside the fitness bike, including a rectifier module 1, a current sampling resistor 2, a current detection module 3, a voltage divider module 4, and a processor 5. When a fitness person uses the fitness bike, he or she performs work on the pedals of the fitness bike, so that the generator inside the fitness bike generates electricity. The alternating current generated by the generator is converted into direct current after passing through the rectifier module 1 to power the entire circuit. The processor 5 determines the current sampling value of the direct current flowing through the current sampling resistor 2 according to the first voltage signal at both ends of the current sampling resistor 2, and determines the voltage sampling value of the point according to the second voltage signal between the first resistor R1 and the voltage divider module 4, and then calculates the power value according to the current sampling value and the voltage sampling value.

[0066] It should be noted that the generator and the rectifier module 1 are connected via a VH3.96 socket, but the generator and the rectifier module 1 are not limited to being connected via a VH3.96 socket. This application does not make any special restrictions on the specific method and device used for the connection.

[0067] In addition, the rectifier module 1 here is a three-phase full-wave rectifier circuit, but the rectifier module 1 is not limited to a three-phase full-wave rectifier circuit, and the specific configuration of the rectifier module 1 is not particularly limited in this application.

[0068] In addition, considering the limited space inside the fitness bike, the current sampling resistor 2 is usually set as three 0.5R resistors connected in parallel. If a resistor with the same power as the three 0.5R resistors connected in parallel is set, the resistor will be very large. However, the current sampling resistor 2 is not limited to three 0.5R resistors connected in parallel, and the specific setting of the current sampling resistor 2 is not particularly limited in this application.

[0069] It should also be noted that the current detection module 3 here usually includes a voltage amplifier, which amplifies the first voltage signal at both ends of the current sampling resistor 2 through the voltage amplifier, so that the processor 5 calculates the current sampling value through the amplified first voltage signal, but the amplification of the first voltage signal at both ends of the current sampling resistor 2 is not limited to being implemented through the voltage amplifier, and this application does not make any special limitations here.

[0070] In addition, in order to obtain a suitable second voltage signal, the voltage divider module 4 here is usually three 270KΩ resistors connected in series, but the voltage divider module 4 is not limited to three 270KΩ resistors connected in series. The specific setting of the voltage divider module 4 is not particularly limited in this application.

[0071] In summary, this method can determine the amount of work done by a fitness person when using an exercise bike by setting simple components in the circuit, thereby reducing the cost of the exercise bike and truly promoting consumer products; and when a fitness person rides the exercise bike, the processor 5 calculates the average power value by detecting the current and voltage emitted by the generator, and the error is small compared with the actual work done by the fitness person, so the power measurement in this way has high accuracy.

[0072] Please refer to Figure 3 , Figure 3 A circuit diagram of another dynamometer circuit provided by the present invention.

[0073] Based on the above embodiments:

[0074] As a preferred embodiment, the current detection module 3 includes:

[0075] A first operational amplifier resistor R2 with a first end connected to the second end of the current sampling resistor 2 and a second end grounded;

[0076] An operational amplifier 31 having a positive input terminal connected to a first end of a first operational amplifier resistor R2, a negative input terminal connected to a first end of a current sampling resistor 2, and an output terminal connected to a second end of a second operational amplifier resistor R3 and an input terminal of a processor 5, for amplifying the first voltage signal;

[0077] A second operational amplifier resistor R3 having a first end connected to the negative input terminal of the operational amplifier 31 .

[0078] In order to adjust the first voltage signal to within the data range of the processor 5, in this embodiment, the current detection module 3 specifically includes a first operational amplifier resistor R2, a second operational amplifier resistor R3 and an operational amplifier 31. The processor 5 determines the current sampling value of the direct current flowing through the current sampling resistor 2 based on the first voltage signal amplified by the operational amplifier 31.

[0079] It should be noted that the first operational amplifier resistor R2 and the second operational amplifier resistor R3 are usually set to 100KΩ. When the first operational amplifier resistor R2 and the second operational amplifier resistor R3 are both 100KΩ, the amplification factor of the operational amplifier 31 is 100. For example, when the voltage across the current sampling resistor 2 is 2V, after amplification, the voltage output by the output end of the operational amplifier 31 is 200V.

[0080] Of course, the first operational amplifier resistor R2 and the second operational amplifier resistor R3 are not limited to 100KΩ, but are specifically set according to the actual required amplification factor of the second voltage signal, and the present application does not make any special limitation here.

[0081] In addition, the operational amplifier 31 here is usually set to LM358, where the positive input terminal of the operational amplifier 31 is pin 3 of LM358, the negative input terminal is pin 2 of LM358, and the output terminal is pin 1 of LM358, wherein the operational amplifier LM358 is powered by connecting pin 8 to a 5V power supply and pin 4 to ground.

[0082] Of course, the operational amplifier 31 here is not limited to LM358, and the present application does not make any special limitation on the specific model of the operational amplifier 31.

[0083] As a preferred embodiment, it also includes:

[0084] A first current limiting filter module 32 whose input end is connected to the second end of the current sampling resistor 2 and whose output end is connected to the first end of the first operational amplifier resistor R2 and the positive input end of the operational amplifier 31, is used to limit the current flowing through this loop and filter the voltage signal at the second end of the current sampling resistor 2;

[0085] And / or, a second current limiting filter module 33 whose input end is connected to the first end of the current sampling resistor 2 and whose output end is connected to the negative input end of the amplifier module and the first end of the second operational amplifier resistor R3, is used to limit the current flowing through this loop and filter the voltage signal at the first end of the current sampling resistor 2;

[0086] And / or, the first protection module 34 whose input end is connected to the output end of the operational amplifier 31 and whose output end is connected to the input end of the processor 5 is used to filter the amplified first voltage signal.

[0087] In order to make the first voltage signal collected by the current detection module 3 more accurate, and thus make the current sampling value obtained by the processor 5 based on the first voltage signal more accurate. In this embodiment, a first current limiting filter module 32 is provided at the positive input end of the operational amplifier 31, and / or a second current limiting filter module 33 is provided at the negative input end of the operational amplifier 31, and / or a first protection module 34 is provided at the output end of the operational amplifier 31. The first voltage signal collected by the current detection module 3 can be made more accurate, and thus make the current sampling value obtained by the processor 5 based on the first voltage signal more accurate.

[0088] It should be noted that the first current limiting filter module 32 here generally includes a first current limiting resistor whose first end is connected to the second end of the current sampling resistor 2, whose second end is connected to the first end of the first signal input resistor and the first end of the first filter capacitor, a first filter capacitor whose second end is grounded, and a first signal input resistor whose first end is connected to the second end of the first current limiting resistor and the first end of the first filter capacitor, and whose second end is connected to the positive input terminal of the operational amplifier 31.

[0089] Of course, the design of the first current limiting filter module 32 here is not limited to the above-mentioned method, and this application does not make any special limitation here.

[0090] In addition, the second current limiting filter module 33 here generally includes a second current limiting resistor having a first end connected to the first end of the current sampling resistor 2, a second end connected to the first end of the second signal input resistor and the first end of the second filter capacitor, a second filter capacitor having a second end grounded, and a second signal input resistor having a first end connected to the first end of the second filter module 10, a second end connected to the negative input end of the operational amplifier 31 and the first end of the second operational amplifier resistor R3.

[0091] Of course, the design of the second current limiting filter module 33 here is not limited to the above-mentioned method, and this application does not make any special limitation here.

[0092] In addition, the first protection module 34 here generally includes a third current limiting resistor having a first end connected to the output end of the operational amplifier 31, a third filter capacitor having a first end connected to the second end of the third current limiting resistor and a second end connected to ground, a fourth current limiting resistor having a first end connected to the first end of the third filter capacitor and a second end connected to the input end of the processor 5, a second diode having an anode connected to the second end of the fourth current limiting resistor and a cathode connected to a 5V power supply, and a third diode having a cathode connected to the second end of the fourth current limiting resistor and an anode connected to ground.

[0093] Of course, the design of the first protection module 34 here is not limited to the above-mentioned method, and this application does not make any special limitation here.

[0094] As a preferred embodiment, it also includes:

[0095] A limiting module 6 having a first end connected to the first end of the first resistor R1 and a second end connected to the input end of the voltage follower 7, for limiting the second voltage signal;

[0096] A voltage follower 7 whose input end is connected to the second end of the amplitude limiting module 6 and whose output end is connected to the input end of the second protection module 8 is used to stabilize and isolate the second voltage signal after amplitude limiting;

[0097] And / or, the second protection module 8 whose output terminal is connected to the input terminal of the processor 5 is used to filter the second voltage signal after voltage stabilization and isolation.

[0098] In order to make the second voltage signal obtained by the processor 5 more accurate, and thus make the voltage sampling value obtained by the processor 5 based on the second voltage signal more accurate. In this embodiment, a limiting module 6, a voltage follower 7 and a second protection module 8 are added, the limiting module 6 limits the second voltage signal, and then the voltage follower 7 stabilizes and isolates the second voltage signal after limiting, and finally the second protection module 8 filters the second voltage signal after stabilization and isolation, and the processor 5 determines the voltage sampling value based on the filtered second voltage signal. This method can make the second voltage signal obtained by the processor 5 more accurate, and thus make the voltage sampling value obtained by the processor 5 based on the second voltage signal more accurate.

[0099] It should be noted that the limiting module 6 here usually includes a fifth current limiting resistor whose first end is connected to the first end of the first resistor R1, a fourth filter capacitor whose first end is connected to the second end of the fifth current limiting resistor and whose second end is grounded, a fourth diode whose anode is connected to the first end of the fourth filter capacitor and the positive input end of the voltage follower 7 and whose cathode is connected to the negative input end of the voltage follower 7, and a fourth diode whose anode is connected to the negative input end of the voltage follower 7 and whose cathode is connected to the positive input end of the voltage follower 7.

[0100] Of course, the design of the limiting module 6 here is not limited to the above-mentioned method, and this application does not make any special limitation here.

[0101] It should also be noted that the second protection module 8 here usually includes a sixth current limiting resistor having a first end connected to the output end of the voltage follower 7, a fifth filter capacitor having a first end connected to the second end of the sixth current limiting resistor and a second end connected to ground, a sixth diode having an anode connected to the second end of the sixth current limiting resistor and a cathode connected to a 5V power supply, and a seventh diode having a cathode connected to the second end of the sixth current limiting resistor and an anode connected to ground.

[0102] Of course, the design of the second protection module 8 here is not limited to the above-mentioned method, and this application does not make any special limitation here.

[0103] In addition, the voltage follower 7 here is usually LM358, where the positive input end of the voltage follower 7 is pin 5 of LM358, the negative input end is pin 6 of LM358, and the output end is pin 7 of LM358, wherein the voltage follower LM358 is powered by connecting pin 8 to a 5V power supply and pin 4 to ground.

[0104] Of course, the voltage follower 7 here is not limited to LM358, and this application does not make any special limitation here.

[0105] As a preferred embodiment, it also includes:

[0106] A speed detection module 9 whose input end is connected to the input end of the rectifier module 1 and whose output end is connected to the processor 5, and is used to generate a speed pulse signal based on the alternating current generated by the generator;

[0107] The processor 5 is also used to determine whether the generator is in working state based on the speed pulse signal.

[0108] In order for the processor 5 to know whether there is a person using the fitness bike, that is, whether the generator in the fitness bike is running. In this embodiment, a speed detection module 9 is provided, which can generate a speed pulse signal according to the alternating current generated by the generator. When the processor 5 detects the speed pulse signal, it is determined that the generator is in a working state, that is, a person is using the fitness bike at this time; when the processor 5 does not detect the speed pulse signal, it is determined that the generator is not in a working state, that is, no person is using the fitness bike.

[0109] As a preferred embodiment, the speed detection module 9 includes:

[0110] A diode whose anode is connected to the input end of the rectifier module 1 and whose common end serves as the input end of the speed detection module 9 and whose cathode is connected to the first end of the second resistor, is used to generate pulsed direct current based on the alternating current output by the generator;

[0111] a second resistor having a first end connected to the cathode of the diode and a second end connected to ground;

[0112] A first switch module having a control end connected to a first end of a second resistor, a first end connected to the processor 5, and a second end connected to ground, and used for controlling itself to close or open based on pulsed direct current;

[0113] A pull-up resistor with a first end connected to the first power supply and a second end connected to the first end of the first switch module and the processor 5 .

[0114] On the basis of the above embodiment, this embodiment proposes an implementation of the speed detection module 9. In this embodiment, when the fitness person is using the fitness bike, the generator generates AC power. When the AC power voltage generated by the generator is positive, the diode is turned on, and the first switch module is turned on at this time, and the first terminal voltage of the first switch module is pulled down to the ground; when the AC power voltage generated by the generator is negative, the diode is disconnected, and the first switch module is disconnected at this time, and the first terminal voltage of the first switch module is pulled up by the pull-up resistor. It can be seen that the processor 5 can detect the speed pulse signal through this process.

[0115] It should be noted that, in order to prevent other interference signals from causing the first switch module to be misconnected, a second resistor with one end connected to the control end of the first switch module and the other end connected to the ground is provided in the present embodiment. When no fitness person is using the fitness bike, the second resistor pulls the control end of the first switch module down to the ground, so that the first switch module can always remain in the disconnected state.

[0116] In addition, the first switch module here is an NPN (Negative-Positive-Negative, negative-positive-negative) type transistor, but the first switch module is not limited to an NPN type transistor, and the present application does not make any special limitation here.

[0117] As a preferred embodiment, it also includes:

[0118] A filter module 10 having a first end connected to the positive output end of the rectifier module 1 and a second end connected to the second end of the current sampling resistor 2, for filtering the direct current output by the rectifier module 1;

[0119] The resistance adjustment module 11 , whose first end is connected to the first end of the filter module 10 and whose second end is connected to the second end of the filter module 10 , is used for controlling the load to perform corresponding resistance adjustment after receiving a resistance adjustment instruction.

[0120] In order to make the exercise bike more user-friendly, in this embodiment, a filtering module 10 and a resistance adjustment module 11 are provided. The alternating current generated by the generator is converted into direct current through the rectifying module 1. The direct current is filtered through the filtering module 10 and then enters the resistance adjustment circuit. The fitness person can adjust the resistance of the exercise bike pedal by means of a manual knob or the like to achieve different exercise effects.

[0121] It should be noted that the filtering module 10 here usually includes two capacitors connected in parallel, which are respectively used to filter out high-frequency components and low-frequency components in the clutter. The specific model of the capacitor is not particularly limited in this application.

[0122] As a preferred embodiment, the resistance adjustment module 11 includes:

[0123] A second switch module having a control end as an input end of the resistance adjustment module 11, a first end connected to a first end of a load, and a second end grounded, for controlling the magnitude of the current in the circuit based on the resistance adjustment instruction, so that the load performs corresponding resistance adjustment according to the magnitude of the current;

[0124] A third resistor having a first end connected to the control end of the second switch module and a second end connected to the ground;

[0125] A freewheeling module having a positive electrode connected to a first end of the second switch module and a negative electrode connected to a second end of the load and a first end of the filter module 10 .

[0126] Based on the above embodiments, this embodiment proposes an implementation of the resistance adjustment module 11. In this embodiment, when the fitness person increases the resistance by manually turning a knob or the like, the duty cycle of the pulse input from the input end of the adjustment module increases, so that the conduction angle of the second switch module increases, thereby increasing the output current of the second switch module, and the load performs corresponding resistance adjustment according to the magnitude of the current.

[0127] It should be noted that, in order to prevent other interference signals from causing the second switch module to be misconnected, a third resistor is provided in the present embodiment, one end of which is connected to the control end of the second switch module and the other end is grounded. When there is no pulse current at the input end of the resistance adjustment module 11, the third resistor pulls the control end of the second switch module down to the ground, so that the second switch module can always remain in the disconnected state.

[0128] In addition, the load here usually refers to the pedal in the exercise bike, and an electromagnet is usually provided in the pedal. When the fitness person increases the resistance by means of a manual knob or the like, the duty cycle of the pulse current input from the input end of the resistance adjustment module 11 will increase, thereby increasing the conduction angle of the second switch module, and then increasing the output current of the second switch module. When the current of the input load increases, the magnetic force of the electromagnet increases, thereby achieving the effect of increasing the pedal resistance in the exercise bike.

[0129] As a preferred embodiment, the processor 5 is further configured to enter a step based on S21 when determining that the generator is in the working state.

[0130] Considering that the speed pulse signal can be used to determine whether the generator of the fitness bike is in working state, that is, the speed pulse signal can be used to determine whether a fitness person is using the fitness bike. In this embodiment, the processor 5 determines whether the speed detection module 9 detects the speed pulse signal. If the speed pulse signal is detected, the processor 5 enters the step of determining the current sampling value of the direct current flowing through the current sampling resistor 2 based on the first voltage signal, determining the voltage sampling value based on the second voltage signal at the first end of the first resistor R1, and determining the power value based on the current sampling value and the voltage sampling value; if the processor 5 does not detect the speed pulse signal, the current current sampling value and the voltage sampling value are saved, and the processor 5 returns to the step of determining whether the speed detection module 9 detects the speed pulse signal.

[0131] As a preferred embodiment, determining the power value based on the current sampling value and the voltage sampling value includes:

[0132] S221: Calculating an average current value based on current sampling values ​​within a preset time, and calculating an average voltage value based on voltage sampling values ​​within a preset time;

[0133] S222: Determine a power value based on the average voltage value and the average current value.

[0134] In this embodiment, the power value is determined based on the current sampling value and the voltage sampling value. Specifically, the average current value is calculated based on the current sampling value within a preset time, the average voltage value is calculated based on the voltage sampling value within a preset time, and then the power value is determined based on the average voltage value and the average current value.

[0135] The present invention also provides a fitness bike, comprising a generator and the dynamometer circuit as described above.

[0136] For an introduction to the fitness bike provided by the present invention, please refer to the above-mentioned embodiments of the invention, and the present invention will not be described in detail here.

[0137] It should be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0138] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

Claims

1. A dynamometer circuit, applied to a fitness bike, the fitness bike also comprising a generator, characterized in that: include: A rectifier module whose input end is connected to the output end of the generator and whose negative output end is grounded, and is used to convert the alternating current output by the generator into direct current; A current sampling resistor connected in series to the output loop of the rectifier module; A current detection module having a positive input terminal connected to the second terminal of the current sampling resistor module, a negative input terminal connected to the first terminal of the current sampling resistor module, and an output terminal connected to the input terminal of the processor, and used to detect a first voltage signal at both ends of the current sampling resistor; A voltage dividing module having a first end connected to the positive output end of the rectifier module and a second end connected to the first end of the first resistor and the processor; The first resistor having a second end grounded; The processor is configured to determine a current sampling value of the direct current flowing through the current sampling resistor based on the first voltage signal, determine a voltage sampling value based on a second voltage signal at the first end of the first resistor, and determine a power value based on the current sampling value and the voltage sampling value; Determining a power value based on the current sampling value and the voltage sampling value includes: Calculate the average current value based on the current sampling values ​​within the preset time, and calculate the average voltage value based on the voltage sampling values ​​within the preset time; The power value is determined based on the average voltage value and the average current value.

2. The dynamometer circuit according to claim 1, characterized in that: The current detection module comprises: a first operational amplifier resistor whose first end is connected to the second end of the current sampling resistor and whose second end is grounded; An operational amplifier having a positive input terminal connected to the first end of the first operational amplifier resistor, a negative input terminal connected to the first end of the current sampling resistor, and an output terminal connected to the second end of the second operational amplifier resistor and the input terminal of the processor, and used to amplify the first voltage signal; The second operational amplifier resistor has a first end connected to the negative input terminal of the operational amplifier.

3. The dynamometer circuit according to claim 2, characterized in that: Also includes: A first current limiting filter module, the input end of which is connected to the second end of the current sampling resistor, and the output end of which is connected to the first end of the first operational amplifier resistor and the positive input end of the operational amplifier, for limiting the current flowing through the loop and filtering the voltage signal at the second end of the current sampling resistor; and / or, a second current limiting filter module having an input end connected to the first end of the current sampling resistor and an output end connected to the negative input end of the amplification module and the first end of the second operational amplifier resistor, for limiting the current flowing through the loop and filtering the voltage signal at the first end of the current sampling resistor; And / or, a first protection module having an input end connected to the output end of the operational amplifier and an output end connected to the input end of the processor, is used to filter the amplified first voltage signal.

4. The dynamometer circuit according to claim 1, characterized in that: Also includes: A limiting module, the first end of which is connected to the first end of the first resistor and the second end of which is connected to the input end of the voltage follower, for limiting the second voltage signal; A voltage follower whose input end is connected to the second end of the limiting module and whose output end is connected to the input end of the second protection module, and is used to stabilize and isolate the second voltage signal after limiting; And / or, the second protection module, whose output end is connected to the input end of the processor, is used to filter the second voltage signal after voltage stabilization and isolation.

5. The dynamometer circuit according to claim 1, characterized in that: Also includes: a speed detection module having an input end connected to the input end of the rectifier module and an output end connected to the processor, for generating a speed pulse signal based on the alternating current generated by the generator; The processor is further used to determine whether the generator is in working state based on the speed pulse signal.

6. The dynamometer circuit according to claim 5, characterized in that: The speed detection module comprises: a diode having an anode connected to the input end of the rectifier module and a common end serving as the input end of the speed detection module and a cathode connected to the first end of the second resistor, for generating pulsed direct current based on the alternating current output by the generator; the second resistor having a first end connected to the cathode of the diode and a second end grounded; A first switch module having a control end connected to the first end of the second resistor, a first end connected to the processor, and a second end connected to ground, and configured to control itself to be closed or opened based on the pulsed direct current; A pull-up resistor having a first end connected to the first power source and a second end connected to the first end of the first switch module and the processor.

7. The dynamometer circuit according to claim 1, characterized in that: Also includes: A filter module having a first end connected to the positive output end of the rectifier module and a second end connected to the second end of the current sampling resistor, and used for filtering the direct current output by the rectifier module; The resistance adjustment module, whose first end is connected to the first end of the filter module and whose second end is connected to the second end of the filter module, is used for controlling the load to perform corresponding resistance adjustment after receiving a resistance adjustment instruction.

8. The dynamometer circuit according to claim 7, characterized in that: The resistance adjustment module comprises: A second switch module, the control end of which serves as the input end of the resistance adjustment module, the first end of which is connected to the first end of the load, and the second end of which is grounded, is used to control the magnitude of the current in the circuit based on the resistance adjustment instruction, so that the load performs corresponding resistance adjustment according to the magnitude of the current; a third resistor having a first end connected to the control end of the second switch module and a second end connected to the ground; A freewheeling module having a positive electrode connected to the first end of the second switch module and a negative electrode connected to the second end of the load and the first end of the filter module.

9. The dynamometer circuit according to claim 5, characterized in that: The processor is also used to enter the steps of determining a current sampling value of the direct current flowing through the current sampling resistor based on the first voltage signal and determining a voltage sampling value based on a second voltage signal at the first end of the first resistor when it is determined that the generator is in a working state.

10. A fitness bike, comprising a generator, characterized in that: It also includes the dynamometer circuit according to any one of claims 1 to 9.

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