摘要:
An overvoltage and overcurrent protection circuit includes a connection jack, an overvoltage protection switch connected to the connection jack, an overcurrent protection switch, a voltage reference module, an overvoltage and overcurrent detection module, a comparing module, and a current control module. The overcurrent protection switch is connected to the overvoltage protection switch in serials, and further connected to a load. The voltage reference module is to output a reference voltage. The overvoltage and overcurrent detection module is to detect the voltage of the load and the current of the path. The comparing module is to compare the voltage of the load with the reference voltage, when greater, turns off the overvoltage protection switch, when not greater, turns on the overvoltage protection switch. The current control module is to turn off the overcurrent protection switch if greater than the preset value, and turn on the overcurrent protection switch if not greater.
摘要:
An earphone with adjustable impedance is provided. The earphone mainly includes an earphone body, a communication line, an earphone plug, an alter switch and an adjustable impedance unit used for adjusting an impedance of the earphone. The adjustable impedance unit is connected between the earphone plug and the earphone body through the alter switch. The impedance of the earphone can be matched on the output impedance of the media player by adjusting the impedance of the adjustable impedance unit when an earphone is connected with a media player.
摘要:
A three-phase AC voltage regulator is for adjusting a line voltage on transmission lines. The three-phase AC voltage regulator includes a sampling circuit, a reference-voltage circuit, a comparator, a switch, a power supply, and a compensator. The sampling circuit is for sampling the line voltage. The reference-voltage circuit is for receiving a line-to-line voltage from the transmission lines and generating a standard voltage. The comparator is for comparing the line voltage and the standard voltage to obtain a signal. The switch is for being turned on or off based on the signal. The power supply is for supplying various electric powers to the compensator. The compensator is for receiving the electric power and generating compensating voltages. The compensating voltages are used to compensate the line voltage.
摘要:
A testing system for measuring an electronic device includes a main controller for generating a control signal, a signal generator for outputting a predetermined test input signal according to the control signal, an instrument unit having a plurality of instruments, and a testing port having a plurality of probes. The plurality of probes connects corresponding testing points of the electronic device to the signal generator and the instruments. The predetermined test input signal is transmitted to the electronic device via the testing port. The instrument unit processes a test result signal outputted by the electronic device and outputs a result data. The main controller receives the result data and computes whether the result data is within a predetermined range. A related testing method is also provided.
摘要:
A multiple output AC/DC power adapter is provided. The adapter includes an adapter body with an output connector and more than one output plugs configured for connecting with the output connector. The adapter body includes a DC-DC converting circuit having an input terminal, an output terminal, a first adjustment terminal. The output connector includes a positive terminal, a second adjustment terminal and a negative terminal configured for connecting to the output terminal and the first adjustment terminal of the DC-DC converting circuit and ground correspondingly. The output plugs each includes an adjustment resistor having a resistance value different from the other output plugs. Therefore, when equipped with a plurality of output plugs each of the plurality of plugs having different resistor R0, the adapter can supply different output DC voltages for different electronic device.
摘要:
An electronic device allowable a portable apparatus to upload and download data is provided. The electronic device includes an interface, an input unit, a processing unit, a payment management unit, and a transfer management unit. The interface is configured for communicating with an external portable apparatus. The input unit is configured for allowing a user to select data to be downloaded or uploaded. The processing unit is configured for calculating a toll for downloading or uploading the data. The payment management unit is configured for accepting payment according to the toll calculated from the processing unit, and generating a payment received signal to signal the processing unit to generate a data transfer command. The transfer management unit is configured for transmitting the data to the external portable apparatus through the interface according to the data transfer command.
摘要:
An electronic device includes a voice processing unit, a wireless communication unit, and a combining unit. The voice processing unit receives speech signals. The wireless communication unit sends the speech signals to a server. The server converts the speech signals into a text message. The wireless communication unit receives the text message from the server. The combining unit combines the text message and the speech signals into a combined message. The wireless communication unit further sends the combined message to a recipient. A related server is also provided.
摘要:
An AC voltage detection circuit includes a conversion module, a comparison module, and a prompt module. The conversion module connects to an AC power source and converts the AC voltage provided by the AC power source to an AC current, and then converts the AC current to a direct current (DC) voltage reflecting the AC voltage. The comparison module is connected to the conversion module, and compares the DC voltage with a first predetermined voltage and a second lesser predetermined voltage, and produces a control signal when the DC voltage is greater than the first predetermined voltage or less than the second predetermined voltage. The prompt module produces a prompt signal when receiving the control signal.
摘要:
A power supply circuit includes a voltage converting module, a detecting module, a processor, and a selecting module. The voltage converting module includes at least one output port, each of which is connected to one load circuit to form a loop circuit. The detecting module can be selectively connected to a selected one of the formed loop circuits to detect at least one parameter of the loop circuit. The processor controls the selecting module to connect the detecting module to the selected loop circuit, and further determines the current of the loop circuit according to the at least one parameter.
摘要:
A resistance-measuring circuit includes a controller for outputting a PWM signal and further for adjusting the duty cycle of the PWM signal, and a sampling circuit for processing the PWM signal and transmitting the processed PWM signal to the sensor. The sampling circuit samples the signal outputted from the sensor to generate a sampled signal with the voltage thereof changing according to any change in the duty cycle of the PWM signal, and further transmits the sampled signal to the controller. The controller obtains the real-time duty cycle of the PWM signal when the voltage of the sampled signal reaches a threshold voltage, and further calculates the exact resistance of the sensor according to the obtained real-time duty cycle of the PWM signal and the threshold voltage. An electronic device with the resistance-measuring circuit is also provided.