TWI657636B - Power-supply device of induction type power supply system and nfc device identification method of the same - Google Patents

Abstract

A power supply device applied to an inductive power supply system includes a power supply coil, an auxiliary coil, a power supply drive module, an auxiliary drive module, a signal detection module, and a processing module. The power supply driving module drives the power supply coil to transmit a power signal. The auxiliary drive module drives the auxiliary coil to transmit a detection signal when the power supply drive module is in an inoperative state, and drives the auxiliary coil to transmit a data request signal. The signal detection module detects the reflection signal of the corresponding data request signal on the auxiliary coil after the data request signal. When the processing module judges that the signal detection module detects a reflection signal with data characteristics, it keeps the power supply driving module in an inoperative state.

Description

   Power supply device of inductive power supply system and identification method of near field communication device thereof   

The invention relates to an inductive power supply technology, and more particularly, to a power supply device applied to an inductive power supply system and a method for identifying a near field communication device thereof.

In the inductive power supply system, the power supply device drives the power supply coil to generate resonance after sending the electromagnetic energy, and then receives the electromagnetic energy generated by the power supply coil through resonance through the coil of the power receiving device to convert the energy into direct current. Power transmission.

In daily life, smart cards can communicate using technologies such as near field communication (NFC). However, most smart cards require only a small amount of electromagnetic energy to drive them. When the smart card receives excessive electromagnetic energy, it will cause chip damage. If the user inserts the smart card into the power supply coil of the power supply device of the inductive power supply system by mistake, and the power supply device is not provided with a detection mechanism, it will be easy to destroy the smart card chip when transmitting the power signal.

Therefore, how to design a new power supply device applied to an inductive power supply system and a method for identifying a near field communication device to solve the above-mentioned shortcomings is an urgent problem in the industry.

An object of the present invention is to provide a power supply device applied to an inductive power supply system, including: a power supply coil, an auxiliary coil, a power supply drive module, an auxiliary drive module, a signal detection module, and a processing module. The power supply driving module is electrically coupled to the power supply coil, and is configured to drive the power supply coil to transmit a power signal. The auxiliary drive module is electrically coupled to the auxiliary coil, and is configured to drive the auxiliary coil to transmit a detection signal with a frequency higher than the power signal at the first time when the power supply drive module is in an inoperative state, and after the first time, Drive the auxiliary coil to send a data request signal at the second time. The signal detection module is electrically coupled to the auxiliary coil, and is configured to detect a reflection signal corresponding to the data request signal on the auxiliary coil at a third time after the second time of transmitting the data request signal. The processing module determines whether the signal detection module has detected a reflective signal with a data characteristic, and further determines that the power supply driving module is in an inoperative state when the signal detection module detects a reflective signal with a data characteristic.

Another object of the present invention is to provide a near field communication device identification method applied to a power supply device of an inductive power supply system, including: an auxiliary drive module electrically coupled to an auxiliary coil, and electrically coupled to a power supply. When the power supply drive module of the coil is in a non-working state, the auxiliary coil is driven at a first time to transmit a detection signal having a higher frequency than the power signal, and the auxiliary coil is driven to transmit a data request signal at a second time after the first time; The detection module detects the reflection signal of the corresponding data request signal on the auxiliary coil at a third time after the second time of transmitting the data request signal; and enables the processing module to determine whether the signal detection module has detected a data characteristic. Reflected signal; and when the processing module determines that the signal detection module detects a reflected signal with data characteristics, the power supply driving module continues to be in an inoperative state.

The advantage of applying the present invention is that the power supply device uses an auxiliary drive module to transmit a high-frequency detection signal and a data request signal through an auxiliary coil, so that when the processing module determines that the signal detection module detects a reflection signal with data characteristics, Judging the existence of the smart card further disables the power supply driving module and prevents the smart card from being damaged by the power supply coil transmitting the power signal.

1‧‧‧ Inductive power supply system

100‧‧‧ Power supply device

102‧‧‧Power supply coil

104‧‧‧Auxiliary coil

106‧‧‧Power Drive Module

108‧‧‧ auxiliary drive module

110‧‧‧Signal Detection Module

112‧‧‧Processing Module

113A, 113B‧‧‧ Power Switching Elements

114A, 114B‧‧‧Power supply resonance capacitor

116A-116C‧‧‧Detect resonance capacitor

118A, 118B‧‧‧ resistance

120‧‧‧ Digital Analog Converter

122‧‧‧ Comparator

124‧‧‧Divided Voltage Module

130‧‧‧Microcontroller

140‧‧‧Power Supply

150‧‧‧ Power receiving device

152‧‧‧Power receiving coil

154‧‧‧Load Module

160‧‧‧Smart Card

162‧‧‧coil

164‧‧‧Chip Module

170‧‧‧tip module

DR‧‧‧Data Request Signal

DS‧‧‧ detection signal

PS‧‧‧ Power Signal

RS‧‧‧Reflected signal

T1‧‧‧ the first time

T2‧‧‧Second time

T3‧‧‧ Third time

V1‧‧‧ crest voltage

V2, V3‧‧‧value

Vd‧‧‧ Detection voltage

Vr‧‧‧ comparison result

Vref‧‧‧Reference voltage

300‧‧‧ section

Section 302‧‧‧

400‧‧‧Near field communication device identification method

401-411‧‧‧step

FIG. 1 is a block diagram of an inductive power supply system according to an embodiment of the present invention; FIG. 2 is a waveform of a detection voltage received by a comparator in an embodiment of the present invention; and FIG. 3A is an implementation of the present invention In the example, the waveform of the detection voltage and the comparison result is enlarged within T3 time; FIG. 3B is a waveform of the detection voltage and the comparison result being enlarged within T3 time according to another embodiment of the present invention; and FIG. 4 is In an embodiment of the present invention, a flowchart of a method for identifying a near field communication device is provided.

Please refer to Figure 1. FIG. 1 is a block diagram of an inductive power supply system 1 according to an embodiment of the present invention. The inductive power supply system 1 includes a power supply device 100 and a power receiving device 150. The power supply device 100 is configured to generate a power signal PS and wirelessly transmit the power signal PS to the power receiving device 150 to supply power to the power receiving device 150.

The power supply device 100 includes a power supply coil 102, an auxiliary coil 104, a power supply driving module 106, an auxiliary driving module 108, a signal detection module 110, and a processing module 112.

In an embodiment, the power supply driving module 106, the auxiliary driving module 108, the signal detection module 110, and the processing module 112 may be integrated into a single microcontroller 130, and the microcontroller 130 may be electrically coupled to The power supply 140 is configured to receive power from the power supply 140 and operate a module included therein. However, the present invention is not limited to this.

The power supply driving module 106 is electrically coupled to the power supply coil 102 and is configured to drive the power supply coil 102 to transmit a power signal PS. In one embodiment, the power supply driving module 106 is a pulse width modulator, and outputs different oscillation frequencies at different levels under the control of the processing module 112 to drive the power supply coil 102.

In one embodiment, the power supply device 100 further includes power supply resonance capacitors 114A and 114B and power switching elements 113A and 113B, which are electrically coupled to one of the two ends of the power supply coil 102 and the power supply drive module 106, respectively.

When the power supply driving module 106 is in the working state, the power signal PS will be transmitted to the power receiving device 150 in the above manner. In one embodiment, the power receiving device 150 includes a power receiving coil 152 and a load module 154. The power receiving coil 152 is configured to receive the power signal PS and is converted by the load module 154.

When the power supply driving module 106 is in a non-working state, the power supply coil 102 is stopped from being driven to further stop transmitting the power signal PS to the power receiving device 150.

The auxiliary driving module 108 is electrically coupled to the auxiliary coil 104 and is configured to drive the auxiliary coil 104 to transmit the detection signal DS at the first time when the power supply driving module 106 is in an inoperative state, and the first time after the first time. Send data request signal DR at two times. In one embodiment, the auxiliary driving module 108 is a pulse width modulator, and outputs different oscillation frequencies at different levels under the control of the processing module 112 to drive the auxiliary coil 104.

In one embodiment, the power supply device 100 further includes detecting resonance capacitors 116A-116C. Among them, the detection resonance capacitors 116A and 116B are electrically coupled between one of the two ends of the auxiliary coil 104 and the auxiliary drive module 108, and the detection resonance capacitor 116C is electrically coupled between the detection resonance capacitors 116A and 116B. . The detection resonance capacitors 116A-116C are configured to resonate with the auxiliary coil 104 when the auxiliary driving module 108 is driving.

In an embodiment, the power supply device 100 may optionally include a resistor 118A and a resistor 118B, which are connected in series with one of the two ends of the auxiliary coil 104 and the auxiliary driving module in series with the detection resonant capacitor 116A and the detection resonant capacitor 116B, respectively. 108, configured to limit the drive current of the 108 port of the auxiliary drive module to provide protection.

In one embodiment, the power signal PS generated by the power supply driving module 106 driving the power supply coil 102 operates at about 100 kHz, and the detection signal DS and the data request signal DR generated by the auxiliary driving module 108 driving the auxiliary coil 104. It works at about 13.56 MHz or 6.78 MHz. Therefore, the operating frequency band of the auxiliary coil 104 is higher than the operating frequency band of the power supply coil 102.

The signal detection module 110 is configured to detect the reflection signal RS corresponding to the data request signal DR on the auxiliary coil 104 at a third time after the second time. The auxiliary coil 104 overlaps the power supply coil 102 to facilitate detection of the power supply range of the power supply coil 102. In one embodiment, the signal detection module 110 includes a digital analog converter 120 and a comparator 122.

The digital-to-analog converter 120 is configured to generate a reference voltage Vref. The comparator is electrically coupled to the digital analog converter 120 and the auxiliary coil 104, and configured to receive the reference voltage Vref and the detection voltage Vd related to the auxiliary coil 104, so that the comparison result Vr between the reference voltage Vref and the detection voltage Vd Detects reflected signal RS.

In an embodiment, the power supply device 100 may optionally include a voltage dividing module 124 electrically coupled between the auxiliary coil 104 and the comparator 122. The detection voltage Vd received by the comparator 122 is a divided voltage of the voltage of the auxiliary coil 104. However, it should be noted that if the components of the signal detection module 110 have sufficient withstand voltage, the voltage of the auxiliary coil 104 can be directly received without going through the voltage dividing module 124 to be compared with the reference voltage Vref.

The processing module 112 determines whether the signal detection module 110 detects a reflective signal RS with data characteristics to determine whether there is a power supply range of the power supply coil 102 such as, but not limited to, the smart card 160 shown in FIG. 1 . It should be noted that although the smart card 160 is shown with other components in the inductive power supply system 1 in FIG. 1, the smart card 160 is not actually part of the inductive power supply system 1.

In an embodiment, the smart card 160 may be, for example, but not limited to, a module that communicates through near field communication technology. In one embodiment, the smart card 160 may include a coil 162 and a chip module 164. Among them, when the auxiliary driving module 108 drives the auxiliary coil 104 to transmit the detection signal DS and is received by the coil 162 of the smart card 160, it will provide a small amount of power to the smart card 160 to drive the chip module 164 in the smart card 160. Further, after receiving the data request signal DR through the coil 162, the smart card 160 can generate a modulated signal from the chip module 164 to the coil 162 according to the data request signal DR, and reflect it through the coil 162 to reflect the signal RS in the form of a reflected signal RS. Auxiliary coil 104.

When the processing module 112 determines that the signal detection module 110 detects a reflective signal RS with data characteristics, the power supply driving module 106 will continue to be in an inoperative state, so as to prevent the power supply driving module 106 from driving the power supply coil 102. The power signal PS caused damage to the smart card 160.

In one embodiment, the power supply device 100 may optionally include a prompt module 170. When the processing module 112 determines that the signal detection module 110 detects a reflected signal RS with data characteristics, the control prompt module 170 displays, for example, but not limited to, a display light, a buzzer, a speaker, a screen display, or the like. The combined method prompts the user to remove the smart card 160.

When the processing module 112 determines that the signal detection module 110 has not detected the reflected signal RS with data characteristics, the power supply driving module 106 will be placed in a working state to drive the power supply coil 102 to generate a power signal PS, and receive power. The device 150 provides power.

It should be noted that, in an embodiment, because the purpose of the processing module 112 is to provide a mechanism to prevent damage to the smart card 160, it is only necessary to determine whether the reflected signal RS has data characteristics by the signal detection module 110 No need to decode the reflected signal RS.

Please refer to Figure 2. FIG. 2 is a waveform of the detection voltage Vd received by the comparator 122 in an embodiment of the present invention.

The detection mechanism of the signal detection module 110 will be described in detail below with reference to FIG. 1 and FIG. 2.

As shown in FIG. 2, at the first time T1, the auxiliary driving module 108 drives the auxiliary coil 104 to transmit the detection signal DS, so that the comparator 122 of the signal detection module 110 is based on the detection voltage Vd and the reference voltage Vref. As a result of the comparison, the digital analog converter 120 is controlled by the feedback mechanism to track and lock the peak voltage V1 of the detection voltage Vd with the reference voltage Vref.

At the second time T2, the auxiliary driving module 108 drives the auxiliary coil 104 to transmit a data request signal DR. In one embodiment, the data request signal DR is generated by interleaving the driving of the auxiliary coil 104 and starting the driving of the auxiliary coil 104 a plurality of times. This data request signal DR will also be reflected in the detection voltage Vd received by the comparator 122.

When the smart card 160 exists, as described above, the tiny power of the detection signal is received through the coil 162 to drive the chip module 164 inside the smart card 160, so that the chip module 164 is modulated on the coil 162 to The modulated signal is reflected on the auxiliary coil 104 through a load reflection method to form a reflected signal RS, which is reflected on the detection voltage Vd.

In more detail, the reflection signal RS will modulate the amplitude of the detection voltage Vd during the third time T3, so that the amplitude of the detection voltage Vd will rise or fall. Therefore, at the third time T3, the digital analog converter 120 will fine-tune the reference voltage Vref up and down at a pitch value, so that the comparator 122 will perform a comparison between the detection voltage Vd and the fine-tuned reference voltage Vref. To detect whether the reflected signal RS has data characteristics.

In one embodiment, the value of the reference voltage Vref after fine adjustment is V2, and the value of the reference voltage Vref after fine adjustment is V3.

In an embodiment, because the location and distance of the smart card 160 are different, the amplitude of the detection voltage Vd may increase, and the amplitude of the detection voltage Vd may decrease. Therefore, the digital analog converter 120 can finely adjust the reference voltage Vref up and down, or optionally set two sets of signal detection modules 110 to fine-tune the reference voltage Vref of one set at the same time. , And let the reference voltage Vref of another group be fine-tuned downward to accelerate the detection process.

Please refer to Figure 3A. FIG. 3A is an enlarged waveform diagram of the detection voltage Vd and the comparison result Vr within T3 in an embodiment of the present invention. The detection voltage Vd is shown in a lighter gray, and the comparison result Vr is shown in a darker gray.

As shown in FIG. 3A, the digital-to-analog converter 120 first adjusts the value of the reference voltage Vref to V2. When there is a convex signal, an accidentally triggered section (that is, the comparison result of the comparator 122 includes a portion where the detection voltage Vd is greater than the reference voltage Vref) can be regarded as having data characteristics. If the entire section is not triggered (that is, the comparison result of the comparator 122 does not include the part where the detection voltage Vd is greater than the reference voltage Vref), it means that there is no data characteristic.

Therefore, in the section corresponding to the reference voltage Vref of FIG. 3A, since the amplitude of the detection voltage Vd is completely smaller than V2, the presence of the reflected signal RS is not detected.

Next, the digital-to-analog converter 120 adjusts the value of the reference voltage Vref down to V3. When there is a recessed signal, a section that has not been triggered accidentally (that is, the comparison result of the comparator 122 includes a portion where the detection voltage Vd is smaller than the reference voltage Vref) can be regarded as having data characteristics. If the entire section is triggered (that is, the comparison result of the comparator 122 does not include the part where the detection voltage Vd is smaller than the reference voltage Vref), it means that there is no data characteristic.

Therefore, in the section corresponding to the reference voltage Vref of FIG. 3A, the amplitude of the part of the detection voltage Vd will be smaller than V3, so there is a section 300 without a trigger. The processing module 112 determines that the signal detection module 110 detects the reflected signal RS according to the comparison result, and further determines that the smart card 160 exists.

Please refer to Figure 3B. FIG. 3B is a waveform diagram in which the detection voltage Vd is enlarged during T3 in another embodiment of the present invention. The detection voltage Vd is shown in a lighter gray, and the comparison result Vr is shown in a darker gray.

As shown in FIG. 3B, the digital-to-analog converter 120 first trims the value of the reference voltage Vref down to V3. When there is a recessed signal, a section that has not been triggered accidentally (that is, the comparison result of the comparator 122 includes a portion where the detection voltage Vd is smaller than the reference voltage Vref) can be regarded as having data characteristics. If the entire section is triggered (that is, the comparison result of the comparator 122 does not include the part where the detection voltage Vd is smaller than the reference voltage Vref), it means that there is no data characteristic.

Therefore, in the section corresponding to the reference voltage Vref of FIG. 3B, since the amplitude of the detection voltage Vd is completely greater than V3, the presence of the reflected signal RS is not detected.

Next, the digital-to-analog converter 120 fine-tunes the value of the reference voltage Vref to V2. When there is a convex signal, an accidentally triggered section (that is, the comparison result of the comparator 122 includes a portion where the detection voltage Vd is greater than the reference voltage Vref) can be regarded as having data characteristics. If the entire section is not triggered (that is, the comparison result of the comparator 122 does not include the part where the detection voltage Vd is greater than the reference voltage Vref), it means that there is no data characteristic.

Therefore, in the section corresponding to the reference voltage Vref of FIG. 3B, the amplitude of a part of the detection voltage Vd will be greater than V2, so there is a section 302 that is partially triggered. The processing module 112 determines that the signal detection module 110 detects the reflected signal RS according to the comparison result, and further determines that the smart card 160 exists.

The power supply device 100 of the present invention uses the auxiliary driving module 108 to transmit the high-frequency detection signal DS and the data request signal DR through the auxiliary coil 104, and in the manner described above, the reference voltage Vref is adjusted up and down to match the detection voltage Vd. By comparison, the effect of determining whether the signal detection module 110 has detected the reflected signal RS with data characteristics is achieved. When the processing module 112 determines that the signal detection module 110 detects a reflective signal RS with data characteristics, the power supply driving module 106 can be further disabled, and the low-frequency power signal PS generated by the power supply coil 102 can prevent the smart card 160. Cause damage.

Further, since the data request signal DR only needs to be generated in an analog manner, and there is no need to set a module that actually decodes the reflected signal RS, a simple circuit structure can be designed to be implemented and set at a lower cost.

Please refer to Figure 4. FIG. 4 is a flowchart of a near field communication device identification method 400 according to an embodiment of the present invention. The near field communication device identification method 400 can be applied to the power supply device 100 of the inductive power supply system 1 shown in FIG. 1. The near field communication device identification method 400 includes the following steps (it should be understood that the steps mentioned in this embodiment can be adjusted in accordance with the actual needs, except for those in which the order is specifically described, and may even be simultaneous or partial Perform both).

At step 401, detection is started.

At step 402, the auxiliary drive module 108 is caused to drive the auxiliary coil 104 to transmit a detection signal DS with a frequency higher than the power signal PS when the power supply drive module 106 is in an inoperative state.

In step 403, the signal detection module 110 is caused to track and lock the peak voltage V1 of the detection voltage Vd related to the auxiliary coil 104 according to the reference voltage Vref.

At step 404, the auxiliary driving module 108 is caused to drive the auxiliary coil 104 to transmit the data request signal DR at the second time.

In step 405, the digital-to-analog converter 120 is caused to adjust the value of the reference voltage Vref down from V1 to V3, and the signal detection module 110 compares the reference voltage Vref and the detection voltage Vd at a third time.

In step 406, the processing module 112 is caused to determine whether a reflection signal RS having a data characteristic is detected. When there is a recessed signal, an occasionally untriggered section will occur (that is, the comparison result of the comparator 122 includes a portion where the detection voltage Vd is smaller than the reference voltage Vref), which can be regarded as having data characteristics. If the entire section is triggered (that is, the comparison result of the comparator 122 does not include the part where the detection voltage Vd is smaller than the reference voltage Vref), it means that there is no data characteristic.

When the reflected signal RS is not detected, in step 407, the digital-to-analog converter 120 is configured to fine-tune the reference voltage Vref from V1 to V2, and the signal detection module 110 compares the reference voltage Vref at the third time. And the detection voltage Vd.

In step 408, the processing module 112 is caused to determine whether a reflection signal RS having a data characteristic is detected. When there is a convex signal, an accidentally triggered section (that is, the comparison result of the comparator 122 includes a portion where the detection voltage Vd is greater than the reference voltage Vref) can be regarded as having data characteristics. If the entire section is not triggered (that is, the comparison result of the comparator 122 does not include the part where the detection voltage Vd is greater than the reference voltage Vref), it means that there is no data characteristic.

When the processing module 112 determines that the reflected signal RS is not detected, in step 409, the processing module 112 determines that the smart card 160 is not detected. At this time, the processing module 112 can place the power supply driving module 106 in a working state to drive the power supply coil 102 to generate a power signal PS to supply power to the power receiving device 150.

When in step 406 or step 408, the processing module 112 determines that a reflected signal RS is detected, in step 410, the processing module 112 determines that a smart card 160 is detected and keeps the power supply driving module 106 inoperative. status. In step 411, the processing module 112 controls the prompt module 170 to prompt the user to remove the smart card 160.

In an embodiment, after step 411 ends, the process may return to step 401 to perform detection again, and achieve the purpose of continuous detection by polling.

The above descriptions are merely preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, and improvement made within the principles of the present invention shall fall within the protection scope of the present invention.

Claims (20)

A power supply device applied to an inductive power supply system includes: a power supply coil; an auxiliary coil; a power supply drive module electrically coupled to the power supply coil and configured to drive the power supply coil to transmit a power signal; The auxiliary driving module is electrically coupled to the auxiliary coil, and is configured to drive the auxiliary coil to transmit a detection signal at a first time when the power supply driving module is in an inoperative state, and at the first time The latter one drives the auxiliary coil to transmit a data request signal at a second time; a signal detection module is electrically coupled to the auxiliary coil and is configured to be one third after the second time to transmit the data request signal Time to detect a reflection signal corresponding to a data request signal on the auxiliary coil; and a processing module to determine whether the signal detection module detects the reflection signal having a data characteristic, and further determine the signal detection When the module detects the reflection signal having the data characteristics, the power supply driving module is kept in the inoperative state. The power supply device according to claim 1, wherein when the processing module determines that the signal detection module detects the reflected signal with data characteristics, it determines that a smart card is stored in a power supply range of the power supply coil. The power supply device according to claim 1, wherein the processing module does not decode the reflected signal. The power supply device according to claim 1, wherein the signal detection module comprises: a digital analog converter configured to generate a reference voltage; and a comparator electrically coupled to the digital analog converter and the auxiliary The coil is configured to receive the reference voltage and a detection voltage related to the auxiliary coil to detect the reflected signal. The power supply device according to claim 4, wherein the comparator is configured to control the digital analog converter with a feedback mechanism at the first time according to a first comparison result of the detection voltage and the reference voltage. The reference voltage tracks and locks a peak voltage, and the digital analog converter fine-tunes the reference voltage with a pitch value at the third time, so that the comparator compares the detected voltage and one of the reference voltages with a second comparison. As a result, the reflected signal is detected. The power supply device according to claim 5, wherein the digital analog converter fine-tunes the reference voltage upward at the third time with the interval value, and when the second comparison result includes a portion where the detection voltage is greater than the reference voltage trimmed When the reflected signal has the data characteristic, and when the second comparison result does not include a portion where the detection voltage is greater than the reference voltage for trimming, the reflected signal does not have the data characteristic. The power supply device according to claim 5, wherein the digital analog converter fine-tunes the reference voltage downward at the third time with the interval value, and when the second comparison result includes that the detection voltage is smaller than the reference voltage of the fine-tuning In some cases, the reflection signal has the data characteristic, and when the second comparison result does not include a portion in which the detection voltage is smaller than the reference voltage for trimming, the reflection signal does not have the data characteristic. The power supply device according to claim 4, further comprising a voltage dividing module, which is electrically coupled between the auxiliary coil and the comparator, and the detection voltage received by the comparator is one of the voltages of the auxiliary coil. Partial pressure. The power supply device according to claim 1, wherein the auxiliary driving module generates the data request signal by interleaving a plurality of times to stop driving and start driving the auxiliary coil. The power supply device according to claim 1, wherein when the processing module determines that the signal detection module does not detect the reflection signal having the data characteristic, the power supply driving module is placed in a working state to The power supply coil is driven to transmit the power signal. A method for identifying a near field communication device, which is applied to a power supply device of an inductive power supply system, includes: an auxiliary drive module electrically coupled to an auxiliary coil, and electrically coupled to one of a power supply coil When the power supply driving module is in an inoperative state, the auxiliary coil is driven at a first time to transmit a detection signal higher than one of the power signals, and the auxiliary coil is transmitted at a second time after the first time A data request signal; enabling a signal detection module to detect a reflection signal corresponding to the data request signal on the auxiliary coil at a third time after the second time transmitting the data request signal; and enabling a processing module The group determines whether the signal detection module detects the reflection signal having a data characteristic; and causes the processing module to cause the signal detection module to determine the reflection signal having the data characteristic to make the reflection signal The power supply drive module continues to be in this inoperative state. The identification method for a near field communication device according to claim 11, further comprising: when the processing module determines that the auxiliary driving module receives the reflected signal through the auxiliary coil, determines that there is a power supply range of the power supply coil A smart card. The method for identifying a near field communication device according to claim 11, further comprising: enabling the processing module not to decode the reflected signal. The method for identifying a near field communication device according to claim 11, further comprising: causing a digital analog converter of the signal detection module to generate a reference voltage; and causing a comparator of the signal detection module to receive the reference. The voltage and a detection voltage related to one of the auxiliary coils to detect the reflected signal. The identification method of a near field communication device according to claim 14, further comprising: enabling the comparator to control the digital at a first time based on a first comparison result of the detection voltage and the reference voltage by a feedback mechanism. The analog converter tracks and locks a peak voltage with the reference voltage; and causes the digital analog converter to fine-tune the reference voltage at the third time, so that the comparator is based on the detection voltage and one of the reference voltages. The second comparison result detects the reflected signal. The identification method of a near field communication device according to claim 15, wherein the digital analog converter fine-tunes the reference voltage upward at the third time with the interval value, and when the second comparison result includes the detection voltage is greater than the fine-tuned the When the reference voltage is part, the reflected signal has the data characteristics, and when the second comparison result does not include the part where the detection voltage is greater than the reference voltage for trimming, the reflected signal does not have the data characteristics. The identification method of a near field communication device according to claim 15, wherein the digital analog converter fine-tunes the reference voltage downward at the third time with the pitch value, and when the second comparison result includes that the detection voltage is less than the fine-tuned When the reference voltage is part, the reflected signal has the data characteristic, and when the second comparison result does not include the part where the detection voltage is smaller than the reference voltage for trimming, the reflected signal does not have the data characteristic. The method for identifying a near field communication device according to claim 11, further comprising: causing the comparator to receive a divided voltage of a voltage of the auxiliary coil as the detection voltage. The method for identifying a near field communication device according to claim 11, further comprising: interleaving the auxiliary driving module to repeatedly stop driving and start driving the auxiliary coil to generate the data request signal. The method for identifying a near field communication device according to claim 11, further comprising: when the processing module determines that the signal detection module has not detected the reflected signal having the data characteristic, the power supply driving module The group is in a working state to drive the power supply coil to transmit the power signal.