Abstract: A pouch air valve includes a hollow tube, a first suction plate, a second suction plate and an air valve. The hollow tube has a central passage running through two sides thereof. The air valve fills and seals the central passage. The first and second suction plates encircle the outer wall of the hollow tube and suck the sealed pouch respectively to couple each other. A method for using includes the following steps: preparing a pliable sealed pouch and forming on the sealed pouch an aperture smaller than suction areas of the first and second suction plates; running the hollow tube through the aperture and positioning the first and second suction plates at two sides of the sealed pouch to couple each other. Air can be sucked out from the sealed pouch for vacuuming or fresh-keeping gas can be injected into the sealed pouch to meet requirements.

Abstract: An airtight cover aims to cover an opening edge of a container and includes an upper rigid lid and an airtight flexible plate located below the upper rigid lid. The airtight flexible plate includes a sealing rim in contact with the opening edge and a central portion and a peripheral portion located respectively on an inner side and an outer side of the sealing rim. The sealing rim and upper rigid lid are interposed by a gap. When the airtight flexible plate contacts with the opening edge through the sealing rim to make the central portion continuously move downward, the peripheral portion is forced to warp upward, and the upper rigid lid presses the peripheral portion to bend downward. Hence the contact area between the sealing rim and opening edge increases, which can securely seal the container to meet requirements of usage.

Abstract: A control circuit, a time calculating unit, and operating method for control circuit are disclosed. The control circuit is operated in a power converter and coupled to a load. The control circuit includes an output stage and a time calculating unit. The time calculating unit receives a control signal and a reference voltage and provides a switch conducting signal to the output stage. The generation of the control signal is related to an output voltage of the power converter. When the difference between the control signal and the reference voltage becomes larger due to the change of the load, the time calculating unit dynamically increases an on-time of the switch conducting signal.

Abstract: A DC-DC controller and a DC-DC converter are provided. The DC-DC converter includes the DC-DC controller and an output stage circuit. The DC-DC controller includes an error amplifier, a comparator, a constant on time calculation circuit, and a ramp generator. The error amplifier receives a first reference voltage and a feedback signal to generate an error signal. The comparator compares a ramp signal and the error signal to generate a trigger signal. The constant on time calculation circuit receives the trigger signal and generates a pulse width modulated signal to the output stage circuit according to the trigger signal, and provides a minimum on time signal. The ramp generator receives the minimum on time signal and generates the ramp signal, wherein an amplitude of the ramp signal has no proportional relationship with an input voltage or an output voltage of the output stage circuit.

Abstract: The disclosure relates to a load-adaptive bioelectrical current stimulator, which comprises a current output module, an adaptation module and a control module. The current output module generates a stimulus current to an electrode. The adaptation module detects the electrical status of the stimulus current passing through the electrode and generates a feedback signal to the control module. According to the feedback signal, the control module controls the current output module to stabilize the output status of the stimulus current adaptively. Thereby, the load-adaptive bioelectrical current stimulator can use the feedback control mechanism to regulate the value of the stimulus current to adapt to variation of load impedance.

Abstract: A DC-DC converter and a voltage conversion method thereof are provided. The DC-DC converter includes an output unit, a control unit and a trigger unit. The output unit converts an input voltage into an output voltage. The control unit generates a control signal according to the input voltage, an output feedback voltage related to the output voltage and a reference voltage, so as to make the output unit generate the output voltage. The trigger unit generates a first trigger signal according to the control signal, the output feedback voltage and the reference voltage. When the output feedback voltage is less than the reference voltage by a preset voltage, the control unit controls the output unit to perform a voltage-regulating process to the output voltage in advance.

Abstract: A pouch air valve includes a hollow tube, a first suction plate, a second suction plate and an air valve. The hollow tube has a central passage running through two sides thereof. The air valve fills and seals the central passage. The first and second suction plates encircle the outer wall of the hollow tube and suck the sealed pouch respectively to couple each other. A method for using includes the following steps: preparing a pliable sealed pouch and forming on the sealed pouch an aperture smaller than suction areas of the first and second suction plates; running the hollow tube through the aperture and positioning the first and second suction plates at two sides of the sealed pouch to couple each other. Air can be sucked out from the sealed pouch for vacuuming or fresh-keeping gas can be injected into the sealed pouch to meet requirements.

Abstract: The disclosure relates to a load-adaptive bioelectrical current stimulator, which comprises a current output module, an adaptation module and a control module. The current output module generates a stimulus current to an electrode. The adaptation module detects the electrical status of the stimulus current passing through the electrode and generates a feedback signal to the control module. According to the feedback signal, the control module controls the current output module to stabilize the output status of the stimulus current adaptively. Thereby, the load-adaptive bioelectrical current stimulator can use the feedback control mechanism to regulate the value of the stimulus current to adapt to variation of load impedance.