Function test circuit of intelligent television box

Abstract

The utility model relates to the technical field of testing, and discloses a function test circuit of a smart television box. The function test circuit comprises a signal acquisition circuit, a voltage selection circuit, a demodulation circuit, a short circuit test circuit and a control circuit. The signal acquisition circuit is configured to acquire a polarization voltage signal, a USB voltage signal and a communication carrier signal of the smart television box, and the control circuit receives the polarization voltage signal or the USB voltage signal output by the voltage selection circuit to output a corresponding voltage test result. And the short-circuit test circuit receives the analog Diseqc signal output by the demodulation circuit, encodes the analog Diseqc signal to output a corresponding signal encoding result, and outputs a corresponding signal short-circuit test result when the short-circuit test circuit is in short-circuit connection with the polarization voltage signal, the USB voltage signal and the communication carrier signal. According to the embodiment of the invention, the accuracy and the test efficiency of the function test of the smart television box can be improved.

Description

Technical Field

[0001] The present application relates to the field of testing technology, and in particular to a functional testing circuit for a smart TV box. Background Art

[0002] Smart TV boxes have been widely used. In order to better meet people's requirements for TV signal quality, each smart TV box must undergo rigorous testing before leaving the factory.

[0003] In the related art, the functional testing of smart TV boxes is all done manually by testers, that is, the testers connect the smart TV boxes to a dedicated demodulation module, which includes 22kHz demodulation and DiSEqc signal demodulation. By changing the on and off states of the channels, the testers use a multimeter to measure whether the offset voltage is output through the specified channel, thereby determining whether the satellite module functions properly.

[0004] The above method is completely dependent on manual operation of each device, so the test efficiency is low. At the same time, the test results are completely determined by manual subjective judgment, so the test results are unstable and have low accuracy. Utility Model Content

[0005] The purpose of this application is to provide a functional test circuit for a smart TV box, aiming to improve the accuracy and test efficiency of the functional test of the smart TV box.

[0006] The present application embodiment provides a functional test circuit for a smart TV box, including:

[0007] A signal acquisition circuit, used to connect to the smart TV box, and configured to acquire a polarization voltage signal, a USB voltage signal, and a communication carrier signal of the smart TV box;

[0008] A voltage selection circuit, connected to the signal acquisition circuit, configured to access the polarization voltage signal and the USB voltage signal, and output the polarization voltage signal or the USB voltage signal;

[0009] A demodulation circuit, connected to the signal acquisition circuit, configured to parse the communication carrier signal to parse out an analog Diseqc signal from the communication carrier signal;

[0010] a short-circuit test circuit, connected to the signal acquisition circuit, and configured to short-circuit the polarization voltage signal and the communication carrier signal; and

[0011] The control circuit is connected to the voltage selection circuit, the demodulation circuit and the short-circuit test circuit, and is configured to receive the polarization voltage signal or the USB voltage signal to output a corresponding voltage test result, receive the analog Diseqc signal and encode it to output a corresponding signal encoding result, and output a corresponding signal short-circuit test result when the polarization voltage signal and the communication carrier signal are short-circuited.

[0012] In some embodiments, the signal acquisition circuit includes a first signal acquisition subcircuit and a second signal acquisition subcircuit;

[0013] The first signal acquisition subcircuit is used to connect to the LNB tuner of the smart TV box, and is configured to collect the polarization voltage signal from the LNB tuner of the smart TV box and collect the communication carrier signal from the communication carrier interface of the smart TV box;

[0014] The second signal acquisition subcircuit is used to connect to the USB interface of the smart TV box and is configured to acquire the USB voltage signal from the USB interface of the smart TV box.

[0015] In some embodiments, the voltage selection circuit includes a selection switch and a first voltage regulator tube;

[0016] The first connection end of the selection switch is connected to the polarization voltage signal through the signal acquisition circuit, the second connection end of the selection switch is connected to the USB voltage signal through the signal acquisition circuit, the common connection end of the selection switch is connected to the control circuit, the first end of the first voltage regulator is connected to the common connection end of the selection switch, and the second end of the first voltage regulator is grounded.

[0017] In some embodiments, the demodulation circuit includes a signal amplification subcircuit, an envelope detection subcircuit, and a signal output subcircuit;

[0018] The signal amplification subcircuit is connected to the communication carrier signal through the signal acquisition circuit, and is configured to amplify the communication carrier signal and output the amplified communication carrier signal;

[0019] The envelope detection subcircuit is connected to the signal amplification subcircuit and is configured to perform waveform conversion on the amplified communication carrier signal and output the waveform-converted communication carrier signal;

[0020] The signal output subcircuit is connected to the envelope detection subcircuit and is configured to parse out the analog Diseqc signal from the communication carrier signal after the waveform conversion.

[0021] In some embodiments, the signal amplification subcircuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a second capacitor, a third capacitor and a first transistor, the base of the first transistor is respectively connected to one end of the first capacitor, one end of the second resistor and one end of the fourth resistor, the collector of the first transistor is respectively connected to one end of the third resistor and one end of the third capacitor, the emitter of the first transistor is respectively connected to one end of the fifth resistor and one end of the second capacitor, the other end of the first capacitor is connected to one end of the first resistor, the other end of the first resistor is respectively connected to the other end of the second resistor, the other end of the third resistor and the signal acquisition circuit, and the other end of the fourth resistor, the other end of the fifth resistor and the other end of the second capacitor are grounded;

[0022] The envelope detection subcircuit comprises a sixth resistor, a seventh resistor, a fourth capacitor, a fifth capacitor, a first diode and a second diode, wherein a cathode of the first diode and an anode of the second diode are respectively connected to the other end of the third capacitor, an anode of the second diode is respectively connected to one end of the sixth resistor and one end of the fourth capacitor, the other end of the sixth resistor is respectively connected to one end of the seventh resistor and one end of the fifth capacitor, and a cathode of the first diode, the other end of the fourth capacitor and the other end of the fifth capacitor are grounded;

[0023] The signal output subcircuit includes an eighth resistor, a ninth resistor, a sixth capacitor and a second transistor, the base of the second transistor is respectively connected to the other end of the seventh resistor and one end of the eighth resistor, the collector of the second transistor is respectively connected to the control circuit and one end of the ninth resistor, the other end of the ninth resistor is respectively connected to a DC source and one end of the sixth capacitor, and the emitter of the second transistor, the other end of the eighth resistor and the other end of the sixth capacitor are grounded.

[0024] In some embodiments, the short circuit test circuit includes a key switch and a second voltage regulator tube;

[0025] The first end of the key switch and the first end of the second voltage regulator are connected to the signal acquisition circuit, and the second end of the key switch and the second end of the second voltage regulator are grounded.

[0026] In some embodiments, the functional testing circuit of the smart TV box further includes a display;

[0027] The display is connected to the control circuit and is configured to receive the test result signal output by the control circuit to display corresponding test result content.

[0028] In some embodiments, the functional testing circuit of the smart TV box further includes a power supply circuit, which is configured to step down and convert an external power supply into direct current with a target voltage.

[0029] In some embodiments, the control circuit is a microprocessor.

[0030] The beneficial effects of the present application are as follows: a polarization voltage signal or a USB voltage signal is accessed by a voltage selection circuit, a communication carrier signal is demodulated by a demodulation circuit to obtain an analog Diseqc signal, a polarization voltage signal, a USB voltage signal and a communication carrier signal are short-circuited by a short-circuit test circuit, a control circuit is used to receive the voltage signal output by the voltage selection circuit to output a corresponding voltage test result, an analog Diseqc signal is received and encoded to output a corresponding signal encoding result, and a corresponding signal short-circuit test result is output when the polarization voltage signal and the communication carrier signal are short-circuited, thereby realizing rapid testing of various functions of the smart TV box and improving the accuracy and efficiency of the functional testing of the smart TV box. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a functional test circuit of a smart TV box provided in the first embodiment of the present application.

[0032] Figure 2 It is a structural diagram of a functional test circuit of a smart TV box provided in the second embodiment of the present application.

[0033] Figure 3 It is a schematic diagram of the structure of a voltage selection circuit provided in one embodiment of the present application.

[0034] Figure 4 It is a structural schematic diagram of a short-circuit test circuit provided in one embodiment of the present application.

[0035] Figure 5 It is a structural schematic diagram of a demodulation circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] It should be noted that the terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or circuits is not necessarily limited to those steps or circuits clearly listed, but may include other steps or circuits that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0039] An embodiment of the present application provides a functional testing circuit for a smart TV box.

[0040] See also Figure 1 In one embodiment, the functional test circuit of the smart TV box includes a signal acquisition circuit 10, a voltage selection circuit 20, a demodulation circuit 30, a short circuit test circuit 40 and a control circuit 50.

[0041] The signal acquisition circuit 10 is used to connect to the smart TV box, and the signal acquisition circuit 10 is configured to collect the polarization voltage signal, USB voltage signal and communication carrier signal of the smart TV box. The voltage selection circuit 20 is connected to the signal acquisition circuit 10, and the voltage selection circuit 20 is configured to access the polarization voltage signal and the USB voltage signal, and output the polarization voltage signal or the USB voltage signal. The demodulation circuit 30 is connected to the signal acquisition circuit 10, and the demodulation circuit 30 is configured to parse the communication carrier signal to parse the analog Diseqc signal from the communication carrier signal. The short-circuit test circuit 40 is connected to the signal acquisition circuit 10, and the short-circuit test circuit 40 is configured to short-circuit the polarization voltage signal and the communication carrier signal. The control circuit 50 is connected to the voltage selection circuit 20, the demodulation circuit 30 and the short-circuit test circuit 40, and the control circuit 50 is configured to receive the polarization voltage signal or the USB voltage signal to output the corresponding voltage test result, receive the analog Diseqc signal and encode it to output the corresponding signal encoding result, and output the corresponding signal short-circuit test result when the polarization voltage signal and the communication carrier signal are short-circuited.

[0042] When collecting signals from the smart TV box, the signal collection circuit 10 is connected to the LNB tuner and the USB interface of the smart TV box, collects polarization voltage signals and communication carrier signals through the LNB tuner, and collects USB voltage signals through the USB interface.

[0043] When the voltage signal of the smart TV box is tested, the voltage selection circuit 20 is provided with two voltage access branches, and one of the two voltage access branches is opened. When the voltage access branch is opened, the accessed voltage signal is output to the control circuit 50. One voltage access branch is connected to the polarization voltage signal from the signal acquisition circuit 10, and the other voltage access branch is connected to the USB voltage signal from the signal acquisition circuit 10. The control circuit 50 performs voltage detection on the voltage signal output by the voltage selection circuit 20, that is, when the voltage selection circuit 20 outputs the polarization voltage signal, the control circuit 50 performs voltage detection on the polarization voltage signal, and when the voltage selection circuit 20 outputs the USB voltage signal, the control circuit 50 performs voltage detection on the USB voltage signal, and the control circuit 50 outputs the corresponding voltage test result.

[0044] When the Diseqc signal test is performed on the smart TV box, the demodulation circuit 30 performs signal amplification, envelope detection and signal simulation processing on the communication carrier signal in turn, so as to demodulate the communication carrier signal and output it as an analog Diseqc signal of a rectangular wave signal. The control circuit 50 receives the analog Diseqc signal and encodes it, and outputs the corresponding signal encoding result, so that the tester can judge whether the DISEQC signal is normal according to the signal encoding result. Specifically, the frequency of the analog Diseqc signal is the frequency of the communication carrier signal, and the duty cycle of the analog Diseqc signal (that is, the proportion of high-level signals in each cycle of the rectangular wave signal) is characterized as the performance of the DISEQC signal in the communication carrier signal. In other words, the smart TV and the output communication carrier signal contain the DISEQC signal. If the duty cycle of the demodulated signal is within the preset duty cycle range, it means that the DISEQC signal is normal. Among them, the preset duty cycle range and the preset frequency are set by the R&D personnel according to the needs.

[0045] When performing a signal short-circuit test on the smart TV box, the short-circuit test circuit 40 accesses the polarization voltage signal and the communication carrier signal from the signal acquisition circuit 10 to short-circuit the polarization voltage signal and the communication carrier signal. The control circuit 50 monitors the state of the smart TV box to determine whether the smart TV box enters the corresponding short-circuit protection state to test the short-circuit protection function of the smart TV box. After the short-circuit test is completed, the short-circuit test circuit 40 restores the normal signal flow of the polarization voltage signal and the communication carrier signal.

[0046] See also Figure 2In some embodiments, the signal acquisition circuit 10 includes a first signal acquisition subcircuit 11 and a second signal acquisition subcircuit 12. The first signal acquisition subcircuit 11 is used to connect to the LNB tuner of the smart TV box, and the first signal acquisition subcircuit 11 is configured to collect polarization voltage signals from the LNB tuner of the smart TV box and to collect communication carrier signals from the communication carrier interface of the smart TV box. The second signal acquisition subcircuit 12 is used to connect to the USB interface of the smart TV box, and the second signal acquisition subcircuit 12 is configured to collect USB voltage signals from the USB interface of the smart TV box.

[0047] See also Figure 3 In some embodiments, the voltage selection circuit 20 includes a selection switch S1 and a first voltage regulator ZD1. The first connection end of the selection switch S1 is connected to the polarization voltage signal through the signal acquisition circuit 10, and the second connection end of the selection switch S1 is connected to the USB voltage signal through the signal acquisition circuit 10. The common connection end of the selection switch S1 is connected to the control circuit 50, and the first end of the first voltage regulator ZD1 is connected to the common connection end of the selection switch S1, and the second end of the first voltage regulator ZD1 is grounded. Specifically, when it is necessary to perform voltage detection on the polarization voltage signal, the selection switch S1 connects its first connection end and the control circuit 50, so that the polarization voltage signal is connected to the control circuit 50 through the selection switch S1, and voltage detection is performed in the control circuit 50. When it is necessary to perform voltage detection on the USB voltage signal, the selection switch S1 connects its second connection end and the control circuit 50, so that the USB voltage signal is connected to the control circuit 50 through the selection switch S1, and voltage detection is performed in the control circuit 50. The first voltage regulator ZD1 is used to keep the voltage signal connected to the control circuit 50 stable.

[0048] See also Figure 5In some embodiments, the demodulation circuit 30 includes a signal amplification subcircuit 31, an envelope detection subcircuit 32, and a signal output subcircuit 33. The signal amplification subcircuit 31 is connected to the communication carrier signal through the signal acquisition circuit 10, and the signal amplification subcircuit 31 is configured to amplify the communication carrier signal and output the amplified communication carrier signal. The envelope detection subcircuit 32 is connected to the signal amplification subcircuit 31, and the envelope detection subcircuit 32 is configured to perform waveform conversion on the amplified communication carrier signal and output the waveform converted communication carrier signal. The signal output subcircuit 33 is connected to the envelope detection subcircuit 32, and the signal output subcircuit 33 is configured to parse the analog Diseqc signal from the waveform converted communication carrier signal. Specifically, since the amplitude of the Diseqc signal is small, the communication carrier signal is amplified by the signal amplification subcircuit 31 to obtain an amplified communication carrier signal, and then the amplified communication carrier signal is transmitted to the envelope detection subcircuit 32. The envelope detection subcircuit 32 performs waveform conversion on the amplified communication carrier signal to demodulate the waveform-converted communication carrier signal. The waveform-converted communication carrier signal is a rectangular wave signal. Finally, the waveform-converted communication carrier signal is transmitted to the signal output subcircuit 33. The signal output subcircuit 33 detects the level value of the waveform-converted communication carrier signal, and opens or closes when the level value reaches a preset condition to simulate the waveform of the Diseqc signal and obtain a simulated Diseqc signal.

[0049] More specifically, the signal amplification sub-circuit 31 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second capacitor C2, a third capacitor C3 and a first transistor Q1, the envelope detection sub-circuit 32 includes a sixth resistor R6, a seventh resistor R7, a fourth capacitor C4, a fifth capacitor C5, a first diode D1 and a second diode D2, and the signal output sub-circuit 33 includes an eighth resistor R8, a ninth resistor R9, a sixth capacitor C6 and a second transistor Q2. The base of the first transistor Q1 is respectively connected to one end of the first capacitor C1, one end of the second resistor R2 and one end of the fourth resistor R4, the collector of the first transistor Q1 is respectively connected to one end of the third resistor R3 and one end of the third capacitor C3, the emitter of the first transistor Q1 is respectively connected to one end of the fifth resistor R5 and one end of the second capacitor C2, the other end of the first capacitor C1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is respectively connected to the other end of the second resistor R2, the other end of the third resistor R3 and the signal acquisition circuit 10, the other end of the fourth resistor R4, the other end of the fifth resistor R5 and the other end of the second capacitor C2 are grounded, the cathode of the first diode D1 and the anode of the second diode D2 are respectively connected to the third The other end of the capacitor C3 and the anode of the second diode D2 are respectively connected to one end of the sixth resistor R6 and one end of the fourth capacitor C4, the other end of the sixth resistor R6 is respectively connected to one end of the seventh resistor R7 and one end of the fifth capacitor C5, the cathode of the first diode D1, the other end of the fourth capacitor C4 and the other end of the fifth capacitor C5 are grounded, the base of the second triode Q2 is respectively connected to the other end of the seventh resistor R7 and one end of the eighth resistor R8, the collector of the second triode Q2 is respectively connected to the control circuit 50 and one end of the ninth resistor R9, the other end of the ninth resistor R9 is respectively connected to the DC source VCC and one end of the sixth capacitor C6, and the emitter of the second triode, the other end of the eighth resistor R8 and the other end of the sixth capacitor C6 are grounded.

[0050] See also Figure 4 In some embodiments, the short-circuit test circuit 40 includes a key switch S2 and a second voltage regulator ZD2. The first end of the key switch S2 and the first end of the second voltage regulator ZD2 are connected to the signal acquisition circuit 10, and the second end of the key switch S2 and the second end of the second voltage regulator ZD2 are grounded. Specifically, when performing a signal short-circuit test on the smart TV box, the key switch S2 is closed, the first end of the key switch S2 is connected to the polarization voltage signal and the communication carrier signal from the signal acquisition circuit 10, and the second end of the key switch S2 grounds the polarization voltage signal and the communication carrier signal to short-circuit the polarization voltage signal and the communication carrier signal. The control circuit 50 monitors the state of the smart TV box and determines whether the smart TV box enters the corresponding short-circuit protection state to test the short-circuit protection function of the smart TV box. After the short-circuit test is completed, the short-circuit test circuit 40 restores the normal signal flow of the polarization voltage signal and the communication carrier signal.

[0051] In some embodiments, the functional test circuit of the smart TV box further includes a display 60. The display 60 is connected to the control circuit 50, and the display 60 is configured to receive the test result signal output by the control circuit 50 to display the corresponding test result content. Specifically, the display 60 displays the voltage test result, signal encoding result, and signal short circuit test result output by the control circuit 50.

[0052] In some embodiments, the functional test circuit of the smart TV box further includes a power supply circuit 70 , and the power supply circuit 70 is configured to convert the external power supply into direct current with a target voltage by stepping down the voltage.

[0053] In some embodiments, the control circuit 50 is a microprocessor.

[0054] In summary, the functional test circuit of the smart TV box provided in the embodiment of the present application uses a voltage selection circuit to access a polarization voltage signal or a USB voltage signal, uses a demodulation circuit to demodulate the communication carrier signal to obtain an analog Diseqc signal, uses a short-circuit test circuit to short-circuit the polarization voltage signal, the USB voltage signal and the communication carrier signal, uses a control circuit to receive the voltage signal output by the voltage selection circuit to output a corresponding voltage test result, receives the analog Diseqc signal and encodes it to output a corresponding signal encoding result, and outputs a corresponding signal short-circuit test result when the polarization voltage signal and the communication carrier signal are short-circuited, thereby realizing rapid testing of various functions of the smart TV box and improving the accuracy and test efficiency of the functional test of the smart TV box.

[0055] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0056] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A functional test circuit for a smart TV box, characterized in that: include: A signal acquisition circuit, used to connect to the smart TV box, and configured to acquire a polarization voltage signal, a USB voltage signal, and a communication carrier signal of the smart TV box; A voltage selection circuit, connected to the signal acquisition circuit, configured to access the polarization voltage signal and the USB voltage signal, and output the polarization voltage signal or the USB voltage signal; A demodulation circuit, connected to the signal acquisition circuit, configured to parse the communication carrier signal to parse out an analog Diseqc signal from the communication carrier signal; A short-circuit test circuit, connected to the signal acquisition circuit, configured to short-circuit the polarization voltage signal and the communication carrier signal; as well as The control circuit is connected to the voltage selection circuit, the demodulation circuit and the short-circuit test circuit, and is configured to receive the polarization voltage signal or the USB voltage signal to output a corresponding voltage test result, receive the analog Diseqc signal and encode it to output a corresponding signal encoding result, and output a corresponding signal short-circuit test result when the polarization voltage signal and the communication carrier signal are short-circuited.

2. The function test circuit of the smart TV box according to claim 1, characterized in that: The signal acquisition circuit includes a first signal acquisition subcircuit and a second signal acquisition subcircuit; The first signal acquisition subcircuit is used to connect to the LNB tuner of the smart TV box, and is configured to collect the polarization voltage signal from the LNB tuner of the smart TV box and collect the communication carrier signal from the communication carrier interface of the smart TV box; The second signal acquisition subcircuit is used to connect to the USB interface of the smart TV box and is configured to acquire the USB voltage signal from the USB interface of the smart TV box.

3. The function test circuit of the smart TV box according to claim 1, characterized in that: The voltage selection circuit includes a selection switch and a first voltage regulator tube; The first connection end of the selection switch is connected to the polarization voltage signal through the signal acquisition circuit, the second connection end of the selection switch is connected to the USB voltage signal through the signal acquisition circuit, the common connection end of the selection switch is connected to the control circuit, the first end of the first voltage regulator is connected to the common connection end of the selection switch, and the second end of the first voltage regulator is grounded.

4. The function test circuit of the smart TV box according to claim 1, characterized in that: The demodulation circuit includes a signal amplification subcircuit, an envelope detection subcircuit and a signal output subcircuit; The signal amplification subcircuit is connected to the communication carrier signal through the signal acquisition circuit, and is configured to amplify the communication carrier signal and output the amplified communication carrier signal; The envelope detection subcircuit is connected to the signal amplification subcircuit and is configured to perform waveform conversion on the amplified communication carrier signal and output the waveform-converted communication carrier signal; The signal output subcircuit is connected to the envelope detection subcircuit and is configured to parse out the analog Diseqc signal from the communication carrier signal after the waveform conversion.

5. The function test circuit of the smart TV box according to claim 4, characterized in that: The signal amplification subcircuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a second capacitor, a third capacitor and a first transistor, the base of the first transistor is respectively connected to one end of the first capacitor, one end of the second resistor and one end of the fourth resistor, the collector of the first transistor is respectively connected to one end of the third resistor and one end of the third capacitor, the emitter of the first transistor is respectively connected to one end of the fifth resistor and one end of the second capacitor, the other end of the first capacitor is connected to one end of the first resistor, the other end of the first resistor is respectively connected to the other end of the second resistor, the other end of the third resistor and the signal acquisition circuit, and the other end of the fourth resistor, the other end of the fifth resistor and the other end of the second capacitor are grounded; The envelope detection subcircuit comprises a sixth resistor, a seventh resistor, a third capacitor, a fourth capacitor, a fifth capacitor, a first diode and a second diode, wherein a cathode of the first diode and an anode of the second diode are respectively connected to the other end of the third capacitor, an anode of the second diode is respectively connected to one end of the sixth resistor and one end of the fourth capacitor, the other end of the sixth resistor is respectively connected to one end of the seventh resistor and one end of the fifth capacitor, and a cathode of the first diode, the other end of the fourth capacitor and the other end of the fifth capacitor are grounded; The signal output subcircuit includes an eighth resistor, a ninth resistor, a sixth capacitor and a second transistor, the base of the second transistor is respectively connected to the other end of the seventh resistor and one end of the eighth resistor, the collector of the second transistor is respectively connected to the control circuit and one end of the ninth resistor, the other end of the ninth resistor is respectively connected to a DC source and one end of the sixth capacitor, and the emitter of the second transistor, the other end of the eighth resistor and the other end of the sixth capacitor are grounded.

6. The function test circuit of the smart TV box according to claim 1, characterized in that: The short circuit test circuit includes a key switch and a second voltage regulator tube; The first end of the key switch and the first end of the second voltage regulator are connected to the signal acquisition circuit, and the second end of the key switch and the second end of the second voltage regulator are grounded.

7. The function test circuit of the smart TV box according to claim 1, characterized in that: The functional testing circuit of the smart TV box also includes a display; The display is connected to the control circuit and is configured to receive the test result signal output by the control circuit to display corresponding test result content.

8. The function test circuit of the smart TV box according to claim 1, characterized in that: The functional test circuit of the smart TV box further includes a power supply circuit, which is configured to convert an external power supply into a direct current with a target voltage by stepping down the voltage.

9. The function test circuit of the smart TV box according to any one of claims 1 to 8, characterized in that: The control circuit is a microprocessor.

Images