TWI481144B - Method of sensing current signal for supplying-end module of induction type power supply system - Google Patents

Description

Current signal detection method in power supply module of inductive power supply

The present invention relates to a current signal detecting method and a related power receiving module in a power supply module for an inductive power supply, and more particularly to detecting a current signal in a power supply module of an inductive power supply. Using the current and drive signal time difference to determine the load level and the presence of metal foreign matter, and to automatically extract the trigger level and current signal trigger to take out the data modulation signal, and analyze the difference between the half cycle current signals to extract the data modulation signal and related Power receiving module.

In the inductive power supply, in order to operate safely, it is necessary to confirm that the sensing area on the power supply coil is the correct power receiving device at the supply end, and to transmit power only when the power can be received, in order to recognize whether it is correct at the power supply end. The power receiving device needs to be identified by data transmission. The transmission of the data code is generated by the power supply terminal driving the power supply coil to generate resonance, transmitting electromagnetic energy to the power receiving end for power transmission, and when receiving power at the power receiving end, the impedance state on the receiving coil can be changed by the signal modulation technique, and then The feedback of the resonant carrier signal on the power supply coil is affected by the feedback. In the prior art, the voltage and current changes occurring on the resonant carrier on the coil need to be taken out by the voltage and current detecting circuit, and the voltage change after the removal needs to remove the resonant carrier from the high frequency alternating current signal through the low pass filter to extract the DC differential signal. It must also be converted to a voltage before it can be processed. The amount of change is very small, so the amplification signal is required to extract the modulated signal. In the Republic of China Patent Application No. 102115983, the signal analysis circuit mainly performs low-pass filtering and de-dc-level coupling, and combines the micro-modulation signal variation into a digital signal by using a circuit such as a comparator. These modulated signals are then interpreted by the software within the microprocessor for decoding.

However, the prior art still has some shortcomings: First, the amount of change in voltage and current is not clear enough and is not stable enough. When entering the signal analysis circuit at the back end, if the amplification ratio is insufficient, the small signal cannot be resolved, and the amplification ratio is too large and easy to mix. Noise, so the circuit is difficult to design and unreliable; second, the amount of voltage and current changes will vary due to different factors such as coil configuration and power transfer size, especially after power is increased, the modulation ratio (main resonant carrier and modulation) The ratio of signal depth will become smaller. If it is difficult to decode correctly, it will become difficult. Therefore, the signal cannot be modulated after being fully loaded. Third, since the signal needs to be filtered and then parsed, the modulation signal on the main resonant carrier changes through the filter. It takes several cycles for the change to occur, and the period of the modulation signal change must be greater than the time after the signal passes through the filter, so the rate at which the data is transmitted is limited. Fourth, the prior art can only be used for signal detection. It is impossible to know the load condition on the coil, such as whether the coil is full or if there is any metal foreign matter; fifth, the signal Analysis of circuits need to use a large number of electronic components, high cost, in addition, the more the parts will cause decreased reliability, a problem as long as one of the parts will cause circuit failure. In view of this, the prior art has been improved.

Therefore, the main object of the present invention is to provide a current signal detecting method and a corresponding power receiving module in a power supply module for an inductive power supply, which can detect a current signal in an inductive power supply. The current and drive signal time difference is used to interpret the load level and metal foreign matter, and the modulation signal is obtained by automatically adjusting the trigger level and the current signal, or by analyzing the difference of the half-cycle current signal to obtain the modulation signal.

The invention discloses a current signal detecting method for a power supply module of an inductive power supply, the power supply module comprising a power supply coil and a resonant capacitor, the method comprising connecting a current detecting component in series to the power feeding coil And obtaining a current signal corresponding to the power supply coil; and parsing the current signal to take out one of the inductive power supply One of the electrical modules.

The invention further provides a power supply module for an inductive power supply, comprising a power supply coil; a resonant capacitor; a current detecting component connected in series between the power supply coil and the resonant capacitor for obtaining a correspondence a current signal of the current of the power supply coil; and a control unit coupled to the current detecting component for analyzing the current signal to take out one of the power receiving modules of the inductive power supply.

10‧‧‧Power supply module

102‧‧‧Power supply coil

104‧‧‧Resonance capacitor

106‧‧‧ Current sensing components

108‧‧‧Control unit

110, 110A, 110B‧‧‧Power supply unit

S1‧‧‧current signal

121A, 121B‧‧‧ drive

123A, 123B‧‧‧Upper bridge switching components

124A, 124B‧‧‧ lower bridge switching components

210‧‧‧Power supply unit

220‧‧‧ display unit

230‧‧‧ Current Zero Comparator

T‧‧‧ switching cycle

702‧‧‧Signal interpretation circuit

A1, A2‧‧ amp amplifier

712, 714‧‧ ‧ level generator

722‧‧‧ positive half cycle comparator

724‧‧‧negative half-cycle comparator

VP‧‧‧ normal phase voltage signal

VN‧‧‧inverted voltage signal

VR1, VR2‧‧‧ reference voltage

R1, R2‧‧‧ output

1100‧‧‧Power Module

SP1‧‧‧ half-cycle current signal

SN1‧‧‧ negative half-cycle current signal

FIG. 1 is a schematic diagram of a power supply module according to an embodiment of the present invention.

Fig. 2 is a schematic view showing an embodiment of a power supply module of Fig. 1.

FIG. 3 is a schematic diagram showing the waveforms of the driving signal and the coil signal under the no-load of the inductive power supply according to the embodiment of the present invention.

FIG. 4 is a schematic diagram showing the waveforms of the inductive power supply with load driving signals and coil signals according to an embodiment of the present invention.

FIG. 5 is a schematic diagram showing the waveforms of the driving signal and the coil signal under full load of the inductive power supply according to the embodiment of the present invention.

FIG. 6 is a schematic diagram of driving signals and coil signals when a metal foreign object is placed on the power receiving end of the inductive power supply according to the embodiment of the present invention.

Figure 7 is a schematic diagram of another embodiment of a power supply module.

FIG. 8 is a schematic diagram showing the waveforms of the current signal and the positive half-cycle comparator output during the unmodulated period and during the modulation period according to the embodiment of the present invention.

FIG. 9 is a schematic diagram showing waveforms of current signals and positive half-cycle comparator output during signal modulation according to an embodiment of the present invention.

FIG. 10 is a schematic diagram showing the waveform of a current signal when noise is disturbed during signal modulation according to an embodiment of the present invention.

Figure 11 is a schematic diagram of a power receiving module having a half-wave signal modulation function.

FIG. 12 is a schematic diagram of a current signal during half-wave signal modulation according to an embodiment of the present invention.

Please refer to FIG. 1 , which is a schematic diagram of a power supply module 10 according to an embodiment of the present invention. As shown in FIG. 1 , the power supply module 10 is used for an inductive power supply, which includes a power supply coil 102 , a resonant capacitor 104 , a current detecting component 106 , a control unit 108 , and a power supply driving unit 110 . The power supply coil 102 can transmit energy to the power receiving end and receive a feedback signal from the power receiving end. The resonant capacitor 104 is used to resonate with the power supply coil 102 to generate alternating electromagnetic energy. The current detecting component 106 is connected in series between the power supply coil 102 and the resonant capacitor 104, and can be used to obtain a current signal S1 corresponding to the current of the power supply coil 102. In general, current sensing component 106 can be a current sense resistor, a Hall Effect Current Sensor, or other type of current detector. The control unit 108 is coupled to the current detecting component 106 and can be used to parse the current signal S1 to extract data of a power receiving module of the inductive power supply. The power supply driving unit 110 is used to drive the power supply coil 102 to transmit energy.

Compared with the prior art, the voltage signal or the current signal must be low-pass filtered before being analyzed. The power supply module 10 can directly analyze the current signal S1 and obtain the modulation signal without filtering, that is, the control unit 108 can directly Analyze the AC signal generated by the coil. However, in the AC signal, the method of taking out the accurate current value is very difficult, especially in the wireless charging system, the frequency of the alternating current component is high and the current is large, so it is not easy to handle. In this case, the modulation signal can be obtained by taking the method of generating the trigger signal by taking out the magnitude of the comparison current, and the load state can be read by the current direction detection.

In an embodiment, the power supply module 10 can obtain a load information by changing the direction of the current to indicate the load state of the inductive power supply, and determine whether there is metal foreign matter at the load end of the inductive power supply. Please refer to FIG. 2, and FIG. 2 is a diagram of the power supply module 10 of FIG. Schematic diagram of the manner of application. In this example, the power supply driving unit 110 can perform full-bridge driving on the power supply coil 102. Therefore, the power supply driving unit 110 includes two parts of the power supply driving units 110A and 110B. The power supply driving unit 110A includes a driving device 121A and an upper bridge switching element. 123A and the lower bridge switching element 124A, and the power supply driving unit 12B includes a driving device 121B, an upper bridge switching element 123B, and a lower bridge switching element 124B. On the other hand, the power supply module 10 further includes a power supply unit 210 and a display unit 220. The operation mode of the power supply unit 210 and the display unit 220 has been disclosed in the former Patent Application No. 102115983, which is not described herein.

To obtain the load information of the inductive power supply, refer to the time point of the driving signal switching at the two ends of the power supply coil 102 and the time point at which the coil current is zeroed. Please refer to FIG. 3. FIG. 3 is a schematic diagram showing waveforms of driving signals A, B and coil signals under no-load of the inductive power supply according to an embodiment of the present invention. The driving signals A and B are control signals for controlling the power supply driving units 110A and 110B, respectively, which can drive the power feeding coil 102 and the resonant capacitor 104 to resonate through the internal components of the power supply driving units 110A and 110B. The third figure is a full-bridge drive, that is, the drive signals A and B are reversed switching signals. As shown in FIG. 3, the driving signals A and B are pulled on the power supply coil 102. Under no-load conditions, the current passing through the coil does not encounter resistance, and a triangular wave waveform is presented, and the current is in the power supply coil 102. And the resonant capacitor 104 alternately flows in both directions. When the current alternates in both directions, there is a time point in which there is no current, that is, the time point at which the current returns to zero. In each drive cycle T, the current is reset to zero. In the case of the driving signal A, when the driving signal A is at a high potential, it represents the force of the current pushing up. When the driving signal A falls to a low potential, the current also begins to change direction. At no load, the time during which the drive signal A switches the potential to zero current is approximately one quarter of the switching period T.

Please refer to FIG. 4, which is a schematic diagram of waveforms of the inductive power supply with load signals A, B and coil signals under load according to an embodiment of the present invention. As shown in Fig. 4, after the load is applied, since the power supply coil 102 and the resonant capacitor 104 resonate with the coil and the capacitor of the power receiving end, The change begins with the current. When the load is aggravated, the time point at which the current returns to zero gradually approaches the point in time at which the drive signal A switches to the low potential.

Please refer to FIG. 5. FIG. 5 is a schematic diagram of waveforms of driving signals A, B and coil signals under full load of the inductive power supply according to an embodiment of the present invention. When the inductive power supply is fully loaded, the power supply module 10 has the maximum thrust (ie, maximum energy transfer) to the power receiving end. After the maximum value is exceeded, the power and charging efficiency are reduced. As shown in Fig. 5, in the case of full load, the time point at which the drive signal A switches the potential will be approximately equal to the time point at which the current returns to zero. In addition, when the inductive power supply is overloaded, the time point at which the driving signal A switches the potential lags behind the time point at which the current returns to zero.

In this way, the control unit 108 can determine the load state of the inductive power supply according to the time difference between the time point when the driving signal A is switched from the high potential to the low potential and the time when the current returns to zero, thereby obtaining the load information. When the time difference between the time point at which the driving signal A switches the potential and the time at which the current returns to zero is approximately one quarter of the switching period T of the driving signal A, the control unit 108 determines that the load state of the inductive power supply is unloaded; When the time difference between the time point at which the driving signal A switches the potential and the time at which the current returns to zero is less than one quarter of the switching period T of the driving signal A, the control unit 108 determines that the inductive power supply has a load; and when the driving signal A switches the potential When the time difference between the time point and the time point at which the current returns to zero approaches zero, the control unit 108 determines that the inductive power supply is near the full load state. On the other hand, since the driving signal B and the driving signal A are mutually inverted voltage signals, it can also be judged according to the time point at which the driving signal B switches the potential and the time point at which the current returns to zero, and the determination mode and the driving signal are used as described above. The judgment of A is the same, and will not be described here.

In this example, the current detecting element 106 takes the time point at which the current returns to zero only in the direction of current conversion. In other words, the current detecting component 106 takes the direction of the current for signal interpretation, regardless of the magnitude of the current. Therefore, a current zero comparator 230 can be provided at the output of the current detecting component 106 to generate a corresponding output value according to the direction of the current. For example, when the current In the forward direction, the current zero comparator 230 can output 1 (high potential); when the current is reverse, the current zero comparator 230 outputs 0 (low potential), since the information required by the control unit 108 is current zero. At the point in time, there is no need to limit which direction is positive. In this way, the current zero comparator 230 can transmit the direction information of the current to the control unit 108 and eliminate the current magnitude. The control unit 108 can calculate the time point at which the current returns to zero according to the signal output by the current zero comparator 230.

It is worth noting that the current signal S1 is not necessarily transmitted in the form of current to the comparator or control unit at the back end, it may also be transmitted in voltage form, digital form or other form. For example, in the above embodiment, the current detecting component 106 may include a resistor connected in series between the power supply coil 102 and the resonant capacitor 104. The current signal S1 may be a result of subtracting the voltage across the resistor. The current detecting component 106 then transmits current signal S1 to current zero comparator 230 for comparison with zero potential. In this case, the current signal S1 is a voltage form signal corresponding to one of the coil currents, and the direction of the coil current is determined by comparison with the zero potential.

In one embodiment, the control unit 108 includes a timer for calculating the time difference between the time point at which the current returns to zero and the time point at which the drive signals A and B switch potentials. When the drive signals A and B switch potentials, the control unit 108 starts the timer and starts timing. When the current signal S1 is switched from 1 to 0 or from 0 to 1 (i.e., the time point at which the current returns to zero), the control unit 108 stops timing. Next, the control unit 108 can determine the load state of the inductive power supply according to the length of time obtained by the timer and the switching period T of the driving signals A and B.

Whether in the no-load, heavy-load or full-load state, the current on the power supply coil 102 is not easy to accurately determine, but there must be a zero-return intersection, which can be used to interpret the signal. In this case, since the signal does not need to be processed by the filter, there is no need to wait for the filter to process the signal before the signal is parsed, and the signal processing speed can be improved. In addition, compared to the prior art, the load condition on the detection coil must be limited by the analog amplifier or filter circuit design. The line current and voltage analysis can be calculated, and the present invention can analyze the load condition through the timer and use fewer parts, so it has the advantages of low cost and high reliability. According to the current signal processing technology, the speed and timing capability of the processor are much higher than that of the analog conversion processing circuit. Therefore, the processing of the control unit 108 can greatly improve the signal processing capability. In addition, the time difference interpretation method of the present invention can also be used to determine whether metal foreign matter is present at the load end.

Please refer to FIG. 6. FIG. 6 is a schematic diagram of driving signals A, B and coil signals when metal foreign objects are present at the power receiving end of the inductive power supply according to an embodiment of the present invention. As shown in Fig. 6, when there is a metal foreign object at the power receiving end, the power supply coil 102 generates a great current and voltage change. However, since the metal foreign matter cannot resonate with the power supply coil 102, the phase of the current is still the same as the no-load. The state, that is, the time at which the current returns to zero is still less than one quarter of the switching period T of the time point at which the driving signal A switches the potential. In this way, the control unit 108 can determine whether there is metal foreign matter at the power receiving end by the time point at which the current magnitude and the current return to zero are switched with respect to the driving signal A.

It should be noted that the present invention can obtain the data of the power receiving end without detecting the current change on the power supply coil. In the above embodiment, the obtained data may be related to the load information or whether there is metal foreign matter at the load end. News. However, in the wireless charging technology, the purpose of obtaining data is to determine whether the power receiving end is the correct power receiving device by the interpretation of the modulated data. Therefore, in the following embodiment, the current signal S1 obtained by the current detecting element 106 is interpreted by the modulation signal generated by the power receiving module to obtain the modulated data.

Please refer to FIG. 7 , which is a schematic diagram of another embodiment of the power supply module 10 . The structure of the power supply module 10 in FIG. 7 is similar to that of the power supply module 10 of FIG. 2, and therefore components and signals having the same functions are denoted by the same symbols. The main difference between the power supply module 10 of FIG. 7 and FIG. 2 is that the power supply module 10 of FIG. 7 further includes a signal interpretation circuit 702, and the signal interpretation circuit 702. The amplifiers A1 and A2, the level generators 712 and 714, the positive half cycle comparator 722 and the negative half cycle comparator 724 are included. The amplifiers A1 and A2 can receive the current signal S1, and respectively amplify the portion corresponding to the forward current and the reverse current in the current signal S1, and then convert them into a positive phase voltage signal VP and an inverted voltage signal VN, respectively. The amplifier A1 directly amplifies and converts a portion of the current signal S1 corresponding to the forward current into a positive phase voltage signal VP, and the amplifier A2 inverts a portion of the current signal S1 corresponding to the reverse current and then amplifies the same. An inverted voltage signal VN is generated. In general, since the current signal S1 obtained by the current detecting element 106 is small, it usually needs to be amplified before it can be processed. The inverted signal can be converted to a positive phase signal for signal processing by the backend processor. Level generators 712 and 714 are used to generate reference voltages VR1 and VR2, respectively. The positive half cycle comparator 722 compares the positive phase voltage signal VP and the reference voltage VR1, and triggers the positive half cycle portion of the modulated signal when the positive phase voltage signal VP is greater than the reference voltage VR1. The negative half cycle comparator 724 compares the inverted voltage signal VN and the reference voltage VR2, and triggers a negative half cycle portion of the modulated signal when the inverted voltage signal VN is greater than the reference voltage VR2.

Each time the power supply driving unit 110 is driven, the power supply coil 102 and the resonant capacitor 104 are pulled apart from each other to resonate, and an alternating current is generated. The current of the alternating current varies according to the sensing condition and the driving condition, and the change is converted into the current signal S1 through the current detecting component 106, and since the coil current and the current signal S1 are not low-pass filtered, the current signal S1 is The high frequency signal is not easily converted directly into a digital signal by an analog-to-digital converter (ADC). In this case, a discriminating level may be preset as the reference voltage VR1 or VR2, and the proportional or inverted voltage of the positive phase voltage signal VP is greater than the reference voltage VR1 during a specific period of one of the unmodulated signals of the power receiving module. The signal VN is greater than the ratio of the reference voltage VR2, and the reference voltage VR1 or VR2 is adjusted.

For example, in the positive half cycle signal analysis, please refer to FIG. 8. FIG. 8 is a diagram showing the output of the current signal S1 and the positive half cycle comparator 722 during the signal unmodulated period and the modulation period according to the embodiment of the present invention. Schematic diagram of the waveform of R1. As shown in Fig. 8, during the period when the power receiving module is not modulating the signal, the current signal S1 corresponding to the coil current fluctuates up and down with the noise or coil coupling condition. When the current signal S1 is greater than the reference voltage VR1, The half-cycle comparator 722 can output R1=1, and when the current signal S1 is less than the reference voltage VR1, the positive half-cycle comparator 722 can output R1=0. In this example, the control unit 108 can check whether each current signal S1 is greater than the reference voltage VR1 and trigger the positive half-cycle comparator 722 to generate an output result R1=1 during a specific period when the power receiving module does not modulate the signal. At the same time, calculate the ratio of the trigger in this specific period and produce the output result R1=1. When the ratio of the current signal S1 is high, the control unit 108 can increase the level of the reference voltage VR1 to reduce the trigger amount; when the ratio of the current signal S1 is low, the control unit 108 can lower the level of the reference voltage VR1. The trigger amount is increased; and in the case where the ratio of the current signal S1 is moderate, the control unit 108 maintains the level of the reference voltage VR1. For example, the control unit 108 can control the current signal S1 to trigger and output the ratio of R1=1 to fall between 70% and 80%. If it is determined that the ratio of the current signal S1 is greater than 80% during a period of time, the control unit 108 Increasing the level of the reference voltage VR1 to reduce the trigger amount of the subsequent current signal S1; if it is determined that the ratio of the current signal S1 triggering is less than 70% for a period of time, the control unit lowers the level of the reference voltage VR1 to improve the subsequent current signal The trigger amount of S1. In this way, when the system noise is large and the trigger amount is increased, the control unit 108 can increase the level of the reference voltage VR1 to reduce the trigger amount, thereby preventing the misinterpretation of the modulation signal caused by the noise.

Please refer to FIG. 9. FIG. 9 is a schematic diagram showing waveforms of the current signal S1 and the positive half-cycle comparator 722 output R1 during signal modulation according to an embodiment of the present invention. Fig. 9 is a view showing the waveform during the signal modulation in Fig. 8 for convenience of explanation. As described above, after the reference voltage VR1 is set, if the power receiving end does not modulate the signal, the ratio of the current signal S1 triggering and outputting R1=1 within any period of time should fall between 70% and 80%. If there is no trigger for a long period of time (that is, the output result R1 continues to be 0) or the trigger amount is very small, it means that the power receiving end has started to modulate the signal, as shown in Figure 9. During signal modulation, there will be a large amount of trigger (such as 70%~80%). The amount of triggering over a period of time is minimal (eg less than 20%). In this case, the control unit 108 can obtain the modulation signal according to the amount of the trigger amount in each period. In addition, during signal modulation, the level of the reference voltage VR1 can still be adjusted according to the trigger ratio during the period with a large trigger amount to eliminate noise interference when the system environment changes.

Please refer to FIG. 10. FIG. 10 is a schematic diagram showing the waveform of the current signal S1 when the noise is disturbed during signal modulation according to an embodiment of the present invention. As shown in Figure 10, when the inductive power supply is in operation, the signal may become cluttered due to system settings or environmental factors. In the prior art, the signal needs to be demodulated through the filter, and the signal caused by the noise. Jitter may make the demodulation result unclear. In contrast, with the embodiment of the present invention, an independent current signal S1 can be obtained for each driving cycle, and each current signal S1 can generate an explicit result with or without triggering, and the control unit 108 can compare according to the comparison. The output of the device is R1 or R2 to determine the condition of the signal modulation. In addition, the low-pass filter of the prior art requires more passive components (such as resistors, capacitors, or inductors) to be prone to errors, and the circuit of the present invention uses fewer components and is mainly a highly integrated product. The body circuit is therefore highly stable.

It should be noted that the present invention can directly obtain the modulation signal according to the change of the coil current without filtering the signal. In an embodiment, the control unit 108 can separately correct the current changes of the positive half cycle and the negative half cycle, respectively, and separate the portion of the current signal S1 corresponding to the forward current from the portion of the reverse current and generate a corresponding positive half cycle. After the current signal and the negative half-cycle current signal, the modulation signal is interpreted according to the difference between the two. In the Republic of China Patent Publication No. 201236304 and the Republic of China Patent Application No. 102115983, the power receiving module mainly modulates data by means of full wave signal modulation. The invention uses a half-wave signal modulation method to make a significant difference between the positive half-cycle current signal and the negative half-cycle current signal. For example, please refer to FIG. 11. FIG. 11 is a schematic diagram of a power receiving module 1100 having a half-wave signal modulation function. As shown in Fig. 11, the structure of the power receiving module 1100 is similar to the power receiving mode in the second picture of the former Chinese Patent Application No. 102115983. Group 20, so components and signals having the same function are denoted by the same symbols. The main difference between the power receiving module 1100 and the power receiving module 20 of the Republic of China Patent Application No. 102115983 is that the signal feedback circuit 23 of the power receiving module 1100 does not include the signal modulation resistor B3, the control diode B4, the Zener diode B5, and Switching element B6. Therefore, the power receiving module 1100 performs half-wave signal modulation only through the signal modulation resistor A3. Other modules and components of the power receiving module 1100 are disclosed in the Republic of China Patent Application No. 102115983, which is not described herein.

Please refer to FIG. 12, which is a schematic diagram of a current signal S1 when half-wave signal modulation is performed according to an embodiment of the present invention. As shown in FIG. 12, the current signal S1 can be disassembled into a forward and reverse portion according to the current direction to generate a positive half cycle current signal SP1 and a negative half cycle current signal SN1. During the unmodulated signal, the positive half cycle current signal SP1 and the negative half cycle current signal SN1 continue to generate a certain amount of change, which may be caused by load or noise, and is similar to the current caused by full wave signal modulation. Variety. When the power receiving end starts to perform half-wave signal modulation, the amount of change of the negative half-cycle current signal SN1 is significantly reduced, and the positive half-cycle current signal SP1 only slightly differs. In this case, the control unit 108 can perform signal analysis based on the signal difference between the positive half cycle current signal SP1 and the negative half cycle current signal SN1. For example, when the difference between the signal change amount of the positive half cycle current signal SP1 and the negative half cycle current signal SN1 exceeds a threshold value, the control unit 108 determines that the power receiving end is modulating the signal and starts reading the modulation signal. It should be noted that the signal feedback circuit at the power receiving end does not limit the phase of the half-wave modulation, so the amount of current signal S1 fed back to the power supply coil 102 may appear in the positive half cycle current signal SP1 or the negative half cycle current signal SN1. The control unit 108 only needs to find the difference between the two.

In summary, the power supply module of the present invention can provide a data receiving method. The method can detect the current change on the power supply coil, and obtain the data of the power receiving end without filtering. The data can include the load information of the inductive power supply, the information of the metal foreign object on the power receiving end, or the modulation generated by the power receiving module. Signals, etc. The invention directly processes each current signal, signal by the processor The resolution can be greatly improved, and the processing speed is also increased. At the same time, in the case where the filter is not used, there are fewer circuit components inside the power supply module, and thus it has the advantages of low cost and high reliability.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10‧‧‧Power supply module

102‧‧‧Power supply coil

104‧‧‧Resonance capacitor

106‧‧‧ Current sensing components

108‧‧‧Control unit

110‧‧‧Power supply unit

S1‧‧‧current signal

Claims (29)

A current signal detecting method for a power supply module of an inductive power supply, the power supply module includes a power supply coil and a resonant capacitor, the method comprising: serially connecting a current detecting component to the power supply coil and the Between the resonant capacitors, to obtain a current signal corresponding to the current of the power supply coil; and parsing the current signal to take out one of the power receiving modules of the inductive power supply; wherein the current detecting component obtains The current signal is used to determine the time point at which the current of the power supply coil is zeroed. The method of claim 1, wherein the step of parsing the current signal to retrieve the data of the power receiving module of the inductive power supply comprises: not filtering the current signal before the data is taken out. The method of claim 1, wherein the data includes a load information indicating whether a load state or a load side of the inductive power supply has metal foreign matter. The method of claim 3, wherein the step of parsing the current signal to extract the data of the power receiving module of the inductive power supply comprises: a time point according to the current of the power supply coil being zeroed and the power supply coil The time difference of one of the time points of the driving signal switching of the two ends determines the load state of the inductive power supply, and then the data is taken out. The method of claim 4, wherein the time difference between a time point at which the current of the power supply coil is zeroed and a time point at which the driving signals of the two ends of the power supply coil are switched is determined, and the load state of the inductive power supply is determined. The step of taking out the data includes: starting a timer and starting timing when the potential of the two ends of the power supply coil is switched; When the current of the power supply coil is zeroed, the timing of the timer is stopped; and the load of the inductive power supply is determined according to the length of time obtained by the timer and the switching period of the driving signals of the two ends of the power supply coil. status. The method of claim 4, wherein when the time difference is approximately one quarter of a driving signal switching period of the two ends of the power supply coil, determining that the load state of the inductive power supply is unloaded. The method of claim 4, wherein when the time difference is substantially zero, determining that the load state of the inductive power supply is full. The method of claim 1, wherein the data comprises a modulation signal generated by the power receiving module of the inductive power supply. The method of claim 8, wherein the step of parsing the current signal to extract the data of the power receiving module of the inductive power supply comprises: a portion of the current signal corresponding to a forward current and a The portions of the reverse current are separately amplified and converted into a positive phase voltage signal and an inverted voltage signal respectively; a first reference voltage and a second reference voltage are set; and the positive phase voltage signal and the first reference voltage are compared, Generating a positive half cycle portion of the modulated signal; and comparing the inverted voltage signal and the second reference voltage to generate a negative half cycle portion of the modulated signal. The method of claim 9, wherein the first reference voltage is based on a ratio of the positive phase voltage signal to the first reference voltage during a specific period of the unmodulated signal of the power receiving module. And adjusting, the size of the second reference voltage is adjusted according to a ratio of the inverted voltage signal to the second reference voltage in the specific period. The method of claim 10, wherein when the ratio of the positive phase voltage signal to the first reference voltage is greater than a first threshold value during the specific period, the magnitude of the first reference voltage is increased, and when the specific period is When the ratio of the positive phase voltage signal to the first reference voltage is less than a second threshold, the magnitude of the first reference voltage is decreased. The method of claim 10, wherein when the ratio of the inverted voltage signal to the second reference voltage is greater than a third threshold in the specific period, the size of the second reference voltage is increased, and when the specific period is When the ratio of the inverted voltage signal to the second reference voltage is less than a fourth threshold, the magnitude of the second reference voltage is decreased. The method of claim 8, further comprising: using the half-wave signal modulation method by the power receiving module of the inductive power supply to generate the modulation signal; and generating, corresponding to the modulation signal, the power supply coil The current signal is divided into a positive half cycle current signal and a negative half cycle current signal according to the current direction of the power supply coil. The method of claim 13, wherein the step of parsing the current signal to extract the data of the power receiving module of the inductive power supply comprises: the positive half cycle current signal and the negative half cycle current signal The difference in the amount of change is taken out of the data. A power supply module for an inductive power supply, comprising: a power supply coil; a resonant capacitor; a current detecting component connected in series between the power supply coil and the resonant capacitor for obtaining a current signal corresponding to a current of the power supply coil; and a control unit coupled to the The current detecting component is configured to parse the current signal to take out one of the power receiving modules of the inductive power supply; wherein the current signal obtained by the current detecting component is used to determine the current of the power supply coil Zero time point. The power supply module of claim 15, wherein the control unit does not filter the current signal before the data is taken out. The power supply module of claim 15, wherein the data includes a load information indicating whether a load state or a load side of the inductive power supply has metal foreign matter. The power supply module of claim 17, wherein the control unit determines the inductive power supply according to a time difference between a time point at which the current of the power supply coil is zeroed and a time point at which the driving signal of the two ends of the power supply coil is switched. The load state is further taken out of the data. The power supply module of claim 18, wherein the control unit comprises: a timer for calculating a time point at which the current of the power supply coil is zeroed and a time point at which the driving signals of the two ends of the power supply coil are switched The time difference is determined by the control unit determining the load state of the inductive power supply according to the time difference obtained by the timer and the switching period of the driving signals of the two ends of the power supply coil. The power supply module of claim 18, wherein the time difference is substantially at the two ends of the power supply coil When the driving signal switching period is one quarter, the load state of the inductive power supply is determined to be no-load. The power supply module of claim 18, wherein when the time difference is substantially zero, determining that the load state of the inductive power supply is full. The power supply module of claim 15, wherein the data includes a modulation signal generated by the power receiving module of the inductive power supply. The power supply module of claim 22, further comprising a signal interpretation circuit, the signal interpretation circuit comprising: a first amplifier and a second amplifier for using a portion of the current signal corresponding to a forward current And a portion of the reverse current is separately amplified and converted into a positive phase voltage signal and an inverted voltage signal; a first level generator and a second level generator are respectively configured to set a first reference a voltage and a second reference voltage; a positive half cycle comparator for comparing the positive phase voltage signal and the first reference voltage to generate a positive half cycle portion of the modulated signal; and a negative half cycle comparator And comparing the inverted voltage signal and the second reference voltage to generate a negative half cycle portion of the modulated signal. The power supply module of claim 23, wherein the first reference voltage is adjusted according to a ratio of the positive phase voltage signal to a ratio of the first reference voltage during a specific period of the unmodulated signal of the power receiving module, The magnitude of the second reference voltage is adjusted according to a ratio of the inverted voltage signal to the second reference voltage during the specific period. The power supply module of claim 24, wherein when the ratio of the positive phase voltage signal to the first reference voltage is greater than a first threshold value during the specific period, the size of the first reference voltage is increased, and when The magnitude of the first reference voltage is decreased when the ratio of the positive phase voltage signal to the first reference voltage is less than a second threshold value during a specific period. The power supply module of claim 24, wherein when the ratio of the inverted voltage signal to the second reference voltage is greater than a third threshold in the specific period, the size of the second reference voltage is increased, and when When the ratio of the inverted voltage signal to the second reference voltage is less than a fourth threshold in a specific period, the magnitude of the second reference voltage is decreased. The power supply module of claim 22, wherein the power receiving module of the inductive power supply uses a half wave signal modulation method to generate the modulated signal. The power supply module of claim 27, wherein the power supply module generates the current signal corresponding to the modulated signal, and the control unit divides the current signal into a positive half cycle current according to a current direction of the power supply coil. Signal and a negative half cycle current signal. The power supply module of claim 28, wherein the control unit extracts the data by a difference in the amount of change between the positive half cycle current signal and the negative half cycle current signal.