Abstract: An exemplary method for manufacturing a circuit board includes, firstly, obtaining an insulating substrate, liquid heat-curable adhesive and electrically conductive particles. The electrically conductive particles are added into the liquid heat-curable adhesive. The electrically conductive particles in the heat-curable adhesive are activated by electrical discharge. Secondly, the liquid heat-curable adhesive having activated electrically conductive particles are spread on the insulating substrate to form a heat-curable adhesive layer on the insulating substrate. Thirdly, the heat-curable adhesive layer are exposed to the mid-infrared light by using a photo-mask, the photo-mask has a pattern corresponding to a desired circuit pattern of the circuit board. The electrically conductive particles relocated themselves one by one to form the circuit pattern under irradiation by the mid-infrared light. Finally, the heat-curable adhesive layer are hardening.

Abstract: The present disclosure provides an audio signal amplifying circuit for an electronic device including a processing chip and a speaker. The audio signal amplifying circuit includes an amplifying circuit and an inverting circuit connected to the processing chip to get a first control signal and invert the first control signal to generate a second control signal. The first control signal and/or the second control signal are used to control the operation mode of the amplifying circuit to be in an amplifying mode or in a non-amplifying mode.

Abstract: An exemplary method for manufacturing a circuit board includes, firstly, obtaining an insulating substrate, liquid heat-curable adhesive and electrically conductive particles. The electrically conductive particles are added into the liquid heat-curable adhesive. The electrically conductive particles in the heat-curable adhesive are activated by electrical discharge. Secondly, the liquid heat-curable adhesive having activated electrically conductive particles are spread on the insulating substrate to form a heat-curable adhesive layer on the insulating substrate. Thirdly, the heat-curable adhesive layer are exposed to the mid-infrared light by using a photo-mask, the photo-mask has a pattern corresponding to a desired circuit pattern of the circuit board. The electrically conductive particles relocated themselves one by one to form the circuit pattern under irradiation by the mid-infrared light. Finally, the heat-curable adhesive layer are hardening.

Abstract: A portable electronic device includes a player, a speaker, a control circuit, a switch circuit, and a current limiter. The player is for outputting analog audio signals. The speaker is for transforming the analog audio signals into sound. The control circuit is for generating a first control signal when ambient light intensity is lower than a predetermined value. The switch circuit is for turning on and transmitting the analog audio signals to the speaker when receiving the first control signal. The current limiter is for transmitting the analog audio signals to the speaker when the switch circuit turns off, and for limiting a current flowing through the speaker.

Abstract: A scanning circuit includes n input ports K1˜Kn arranged in n rows L1˜Ln; and m?2 output ports W2˜(m?1) arranged in m columns P1˜Pm. The n rows and the m columns define a switch matrix including n*m switches. Ends of the switches in the same row are connected to one of the n input ports K1˜Kn, respectively. The ends of the switches in the column P1 are connected to ground. The ends of the switches in the same column of the columns P2˜P(m?1) are connected to a power supply VCC via resistors R2˜R(m?1) and the m?2 output ports W2˜W(m?1), respectively. The ends of the switches in the columns Pm are connected to ground via a resistor Rs and the power supply VCC via the resistors R2˜R(m?1) and diodes D2˜D(m?1), respectively.

Abstract: A scanning circuit includes n rows L1˜Ln, 2n columns P1-1˜P1-n and P2-1˜P2-n, and the n rows L1˜Ln and the n columns P1-1˜P1-n cooperatively form a switch matrix comprising n*n switches S1-1˜Sn-n, with ends of the switches in the same row electrically connected to one of n I/O ports K1˜Kn, respectively, the ends of the switches in the same column are electrically connected to ground via one resistor R1-1˜R1-n, respectively, each of resistors R2-1˜R2-n is electronically connected in one column of the columns P2-1˜P2-n, and connected between one of the I/O ports K1˜Kn and ground via one of the resistors R1-1˜R1-n, respectively. A keyboard and a scanning method are also provided.

Abstract: The present disclosure provides an audio signal amplifying circuit for an electronic device including a processing chip and a speaker. The audio signal amplifying circuit includes an amplifying circuit and an inverting circuit connected to the processing chip to get a first control signal and invert the first control signal to generate a second control signal. The first control signal and/or the second control signal are used to control the operation mode of the amplifying circuit to be in an amplifying mode or in a non-amplifying mode.

Abstract: A state switching device for switching the states of a device by detecting a battery voltage of the device is provided. The device includes a voltage dividing circuit to provide an output voltage in proportion to the battery voltage, and a detection unit which includes a voltage detection module, a comparison module, a control module and a state detection module to obtain the device's state. The voltage detection module produces a digital detection voltage according to the output voltage at normal time intervals, the comparison module detects whether the digital detection voltage is lower than a reference voltage corresponding to the state. If yes, the voltage detection module obtains digital detection voltage at abnormal time intervals. The comparison module compares a predetermined number of digital detection voltages with the reference voltage to produce comparison results. The control module determines whether to maintain the device's state according to the comparison results.

Abstract: An amplifier circuit for amplifying audio signal output by an audio source and outputting the amplified audio signal to a speaker is provided. The amplifier circuit includes a peripheral circuit and an amplifier chip including an amplifier, a first, a second, a third resistor, and a fourth resistor. The peripheral circuit includes a fifth and a sixth resistors. The first resistor is connected between a non-inverting input port and an output port of the amplifier, the second resistor is connected between an inverting input port and the output port of the amplifier, the third resistor is connected between the non-inverting input port and the fifth resistor, the fourth resistor is connected between the inverting port and the sixth resistor, the fifth and the sixth resistors are further respectively connected to an anode output port of the audio source and a cathode output port of the audio source.

Abstract: A telephone line monitoring device is connected to a telephone line and adjacent to a telephone device using the telephone line. The telephone line monitoring device includes a rectifying circuit for generating a corresponding direct current voltage according to an effective voltage of the telephone line; a first controller for generating a first control signal when the direct current voltage is lower than a predetermined voltage; a second controller for detecting an operating state of the telephone device and generating a second control signal when the telephone device is operated; a load booster for pulling down the effective voltage of the telephone line when enabled; and a first switch circuit for disabling the load booster whenever receiving the second control signal, and enabling the load booster when receiving the first control signal while not receiving the second control signal. A monitoring method and a telephone device are also provided.

Abstract: A scanning circuit includes n input ports K1˜Kn arranged in n rows L1˜Ln; and m?2 output ports W2˜(m?1) arranged in m columns P1˜Pm. The n rows and the m columns define a switch matrix including n*m switches. Ends of the switches in the same row are connected to one of the n input ports K1˜Kn, respectively. The ends of the switches in the column P1 are connected to ground. The ends of the switches in the same column of the columns P2˜P(m?1) are connected to a power supply VCC via resistors R2˜R(m?1) and the m?2 output ports W2˜W(m?1), respectively. The ends of the switches in the columns Pm are connected to ground via a resistor Rs and the power supply VCC via the resistors R2˜R(m?1) and diodes D2˜D(m?1), respectively.

Abstract: An audio input unit, includes an audio capturing unit, a first coupling circuit, a signal filtering circuit, a second coupling circuit, a converting circuit and a codec which are connected in series in that order. The first coupling circuit is used for filtering the direct-current signal, the signal filtering circuit is used for filtering noise from the electrical signal, and the second coupling circuit is used for further filtering the direct-current signal. The converting circuit includes an input port, a first output port and a second output port, when the input port receives the filtered signal, the first output port outputs a signal with the same phase as the filtered signal, the second output port outputs a signal with the reverse phase as the filtered signal, the two output signals have the opposite phase and the same amplitude.

Abstract: A scanning circuit includes n rows L1˜Ln, 2n columns P1-1˜P1-n and P2-1˜P2-n, and the n rows L1˜Ln and the n columns P1-1˜P1-n cooperatively form a switch matrix comprising n*n switches S1-1˜Sn-n, with ends of the switches in the same row electrically connected to one of n I/O ports K1˜Kn, respectively, the ends of the switches in the same column are electrically connected to ground via one resistor R1-1˜R1-n, respectively, each of resistors R2-1˜R2-n is electronically connected in one column of the columns P2-1˜P2-n, and connected between one of the I/O ports K1˜Kn and ground via one of the resistors R1-1˜R1-n, respectively. A keyboard and a scanning method are also provided.

Abstract: A power-saving circuit is provided for saving electrical power by detecting a presence or absence of an object in a localized area. The power-saving circuit includes a sensor module, and a switch module connected to the sensor module. The detector is adapted for outputting a control signal at a first state when an object is detected in the localized area, and outputting a control signal at a second state when an object is detected not in the localized area. The switch module provides a stable DC voltage according to the control signal at the first state, and not provides the stable DC voltage according to the control signal at the second state.

Abstract: An illumination adjusting device for receiving power from a power supply and supplying output voltage to a lighting unit is provided herein. The illumination adjusting device includes a detector for detecting ambient illumination intensity and generating an ambient illumination value according to the ambient illumination intensity; a comparator for comparing the ambient illumination value with a predetermined value, the comparator outputting a first power signal when the ambient illumination value is lower than a predetermined value; an adjustor for adjusting the output voltage according to the first power signal, as a result, light emitted by the lighting unit is controlled within a predetermined illumination intensity range. A related illumination adjusting method is also provided.

Abstract: An electrical receptacle to prevent injuries deduced by misoperation is provided in the present invention. The electrical receptacle includes a power socket, a direct current (DC) power supply, a detecting switch, a controller, and a relay form a circuit loop for detecting whether a power plug is inserted into the power socket. The detecting switch is placed under the power socket without any electrical connection with the power socket. A live wire is connected to the power socket via a switch of the relay and a neutral wire is connected to the power socket directly. The switch of the relay closes on condition of the relay is electrified by the DC power supply.

Abstract: A projector for automatically adjusting images projected onto a screen includes a detecting module for detecting a propagation time for projected ultrasonic waves sent by the projector to be echoed back by the screen and received by the projector, a processing module for calculating a projection distance between the projector and the screen based on the propagation time, and outputting a focal length signal corresponding to the projection distance, an optical module, and an adjusting module for adjusting a local length of the optical module according to the focal length signal. A related method is also provided.

Abstract: An interface circuit and an electronic device are used for expanding an output port of a micro processing unit. The interface circuit includes an input port electrically connected to the output port of the micro processing unit for receiving a control signals, and a plurality of output ports selectively driven to control external circuits by inputting different values of the control signal at the input port.

Abstract: A battery detection device for detection battery voltage of a device is provided. The device includes a voltage dividing circuit configured to provide an output voltage in proportion to the battery voltage, and a detection unit which includes a voltage detection module, a comparison module, a control module and a state detection module configured to obtain the device's state. The voltage detection module produces a digital detection voltage according to the output voltage every normal time interval initially, the comparison module detects whether the digital detection voltage is lower than a reference voltage corresponding to the state. If yes, the voltage detection module obtains digital detection voltage for predetermined times of abnormal time interval. The comparison module compares the digital detection voltage with the reference voltage to produce comparison results. The control module determines whether to maintain the device's state according to the comparison results.

Abstract: An electrical receptacle to prevent injuries deduced by misoperation is provided in the present invention. The electrical receptacle includes a power socket, a direct current (DC) power supply, a detecting switch, a controller, and a relay form a circuit loop for detecting whether a power plug is inserted into the power socket. The detecting switch is placed under the power socket without any electrical connection with the power socket. A live wire is connected to the power socket via a switch of the relay and a neutral wire is connected to the power socket directly. The switch of the relay closes on condition of the relay is electrified by the DC power supply.