Abstract: A voltmeter of the present disclosure includes a multimeter, a first option switch, a second option switch, a control module, an adjusting power source and a button. The multimeter has a positive probe and a negative probe. The first option switch has two binding posts S1, S2, and a connection pin T1. The second option switch also has two binding posts S3, S4 and a connection pin T2. The positive probe of the multimeter is coupled with the connection pin T1 of the first option switch, the negative probe of the multimeter is coupled with the connection pin T2 of the second option switch. The control module can control the first option switch and the second option switch, and read a value of the multimeter, the multimeter and test a voltage of a circuit by the adjusting power source being equivalent to the voltage of the circuit.

Abstract: A voltmeter of the present disclosure includes a multimeter, a first option switch, a second option switch, a control module, an adjusting power source and a button. The multimeter has a positive probe and a negative probe. The first option switch has two binding posts S1, S2, and a connection pin T1. The second option switch also has two binding posts S3, S4 and a connection pin T2. The positive probe of the multimeter is coupled with the connection pin T1 of the first option switch, the negative probe of the multimeter is coupled with the connection pin T2 of the second option switch. The control module can control the first option switch and the second option switch, and read a value of the multimeter, the multimeter and test a voltage of a circuit by the adjusting power source being equivalent to the voltage of the circuit.

Abstract: The cursor control device includes a housing, a first capacitor, a second capacitor, a first capacitance measurement unit, a second capacitance measurement unit, and a processor. Each capacitor includes a stator plate and a rotor plate. The rotor plates are movable relative to the stator plates. The stator plate and the rotor plate of the first capacitor are substantially perpendicular to the stator plate and the rotor plate of the second capacitor. The capacitance measurement units respectively measure the corresponding capacitance of the capacitors. The processor analyzes acceleration and duration of the changes in capacitance to ascertain movement direction and distance of the device according to the capacitance measured by the capacitance measurement units, when the capacitance between the stator plate and the rotor plate of the first capacitor, or between the stator plate and the rotor plate of the second capacitor changes.

Abstract: A method for automatically switching volume adjustment mode of an electronic device is provided. The method includes: storing a first predetermined volume and a second predetermined volume; when receiving a signal for volume adjustments, judging a current adjustment mode of the electronic device; if the current adjustment mode is the heavy adjustment mode, adjusting the volume with larger increment/decrement; if a value of the volume is larger than or equal to the first predetermined volume, switching to the light adjustment mode automatically; if the adjustment mode is the light adjustment mode, adjusting the volume with smaller increment/decrement; if the volume is less than or equal to the second predetermined volume, switching to the heavy adjustment mode automatically. The present invention also provides an electronic device capable of switching volume adjustment mode automatically.

Abstract: An audio electronic device includes a player, an output device, a detector, and an automatic turn-off module. The player is for reproducing audio data. The output device is for transforming the audio data to audible sound. The detector is for detecting positional shift of the output device. The automatic turn-off module is for turning off the player based on the positional shift. An automatic turn-off method is also disclosed.

Abstract: A charging circuit for charging a rechargeable battery (70) includes a charge management unit (40), a comparator (80) and a changeover switch (60). The changeover switch (60) includes a default state of connecting the rechargeable battery to the comparator (80), so that the comparator (80) produces a comparison result by comparing a battery voltage of the rechargeable battery (70) with a preset voltage threshold. The comparison result is transmitted to the charge management unit (40) and the charge management unit (40) controls the changeover switch (60) to switch from the default state to a controlled state if the battery voltage is less than the preset voltage threshold according to the comparison result. In the controlled state the changeover switch (60) connects the rechargeable battery (70) to the charge management unit (40), so that the charge management unit (40) charges the rechargeable battery (70).

Abstract: A method for automatically switching volume adjustment mode of an electronic device is provided. The method includes: storing a first predetermined volume and a second predetermined volume; when receiving a signal for volume adjustments, judging a current adjustment mode of the electronic device; if the current adjustment mode is the heavy adjustment mode, adjusting the volume with larger increment/decrement; if a value of the volume is larger than or equal to the first predetermined volume, switching to the light adjustment mode automatically; if the adjustment mode is the light adjustment mode, adjusting the volume with smaller increment/decrement; if the volume is less than or equal to the second predetermined volume, switching to the heavy adjustment mode automatically. The present invention also provides an electronic device capable of switching volume adjustment mode automatically.

Abstract: An audio electronic device includes a player, an output device, a detector, and an automatic turn-off module. The player is for reproducing audio data. The output device is for transforming the audio data to audible sound. The detector is for detecting positional shift of the output device. The automatic turn-off module is for turning off the player based on the positional shift. An automatic turn-off method is also disclosed.

Abstract: A switching power supply includes an amplitude control circuit (30) connected between an alternating current (AC) source (10) and a traditional switching power supply (20). The amplitude control circuit includes a power switch (31) and a pulse generator (32). The power switch is connected between the AC source and the traditional switching power supply and is configured for conducting power to the traditional switching power supply when enabled, and the pulse generator is configured for generating rectangular pulses to enable and disable the power switch in an alternating manner.

Abstract: A charging circuit for charging a rechargeable battery (70) includes a charge management unit (40), a comparator (80) and a changeover switch (60). The changeover switch (60) includes a default state of connecting the rechargeable battery to the comparator (80), so that the comparator (80) produces a comparison result by comparing a battery voltage of the rechargeable battery (70) with a preset voltage threshold. The comparison result is transmitted to the charge management unit (40) and the charge management unit (40) controls the changeover switch (60) to switch from the default state to a controlled state if the battery voltage is less than the preset voltage threshold according to the comparison result. In the controlled state the changeover switch (60) connects the rechargeable battery (70) to the charge management unit (40), so that the charge management unit (40) charges the rechargeable battery (70).