7 results about "Variable-voltage power supply" patented technology

Embodiments of the present disclosure include adaptive bias control of cascode drivers in envelope tracking power amplifier devices, systems, and methods. In some aspects, a wireless communication device is disclosed that includes a power amplifier. The power amplifier may include a driver stage configured to receive a variable voltage supply signal, and a power amplifier stage following the driver stage. In some embodiments, the driver stage includes a cascode gate bias circuit configured to receive a first signal that is based on the variable voltage supply signal; and a cascode amplifier stage comprising a first field effect transistor (FET) and a second FET in a stacked configuration. The cascode gate bias circuit may be further configured to adaptively convert the first signal into a bias signal for a gate of the first FET. The power amplifier stage may be configured to generate an amplified signal based on the intermediate output.

The utility model relates to the technical field of power supply, specifically discloses a kind of vehicle-mounted electrical equipment's variable-voltage power supply system, including vehicle battery, overload protector, main distribution box, transformer, variable-voltage distribution box, multiple voltage switching matrix switch and on-off power matrix switch, the vehicle battery is connected with the main distribution box electricity by the overload protector, the main distribution box is connected with the transformer and multiple voltage switching matrix switch electricity respectively, the transformer is connected with the multiple voltage switching matrix switch electricity by the variable-voltage distribution box, the multiple voltage switching matrix switch is connected with vehicle-mounted electrical equipment electricity by the on-off power matrix switch.The variable-voltage power supply system of vehicle-mounted electrical equipment provided by the utility model is convenient to use, voltage switches efficiently, low in cost, reduces connecting wire harness, and safety is improved.

Embodiments of the present disclosure include adaptive bias control of cascode drivers in envelope tracking power amplifier devices, systems, and methods. In some aspects, a wireless communication device is disclosed that includes a power amplifier. The power amplifier may include a driver stage configured to receive a variable voltage supply signal, and a power amplifier stage following the driver stage. In some embodiments, the driver stage includes a cascode gate bias circuit (202) configured to receive a first signal that is based on the variable voltage supply signal; and a cascode amplifier stage (204) comprising a first field effect transistor (Mi) and a second field effect transistor (M2) in a stacked configuration. The cascode gate bias circuit (202) may be further configured to adaptively convert the first signal into a bias signal for a gate of the first field effect transistor (Mi).

The present disclosure relates to a driver circuit for driving a capacitive transducer. The circuit comprises an output stage circuit (330) configured to receive an input signal and drive the capacitive transducer (340) to produce an output signal; a variable voltage power supply circuit (320) configured to output a supply voltage to power the output stage circuit, wherein the supply voltage output by the variable voltage power supply circuit varies based on the input signal; a supply capacitor (326, 328) to receive the supply voltage output by the variable voltage power supply circuit; a storage capacitor (360); and a circuit to transfer charge between the storage capacitor and the supply capacitor (400).

To provide a measuring method capable of simply measuring a contact potential and a relative dielectric constant by utilizing an existing device.SOLUTION: In the Kelvin probe measurement method, a variable voltage power source is electrically connected between a sample to be measured and probe electrodes, distances between the sample to be measured and the probe electrodes are periodically changed, and a current I1 flowing between the sample to be measured and the probe electrodes or a signal voltage I1 after amplifying the current V1 is measured. A contact potential VC is obtained from a voltage V applied by a variable voltage power source when a current I1 or a signal voltage V1 becomes 0, and a relative dielectric constant ε is obtained from ε = ε ' * α / α ' using a slope α of a characteristic curve drawn by a peak-to-peak value Vpeak-to-peak of the signal voltage V1 with respect to the voltage V applied by the variable voltage power source and a slope α ' of a characteristic curve obtained by measuring a reference sample made of a material having a known relative dielectric constant ε ' under the same conditions as those for obtaining the characteristic curve.SELECTED DRAWING: Figure 1

The application provides a DC motor feedback speed regulation system of analog quantity detection control and belongs to the technical field of motor control. The application comprises a base, a variable voltage power supply arranged on the base and used for providing power supply for the DC motor feedback speed regulation system, and an upper plate arranged above the base; a control execution module used for controlling the operation of a DC motor MA, a rotating disc, the DC motor MA used for driving the rotating disc to rotate, and a generator MF rotationally connected with the DC motor MA are arranged on the upper plate; three groups of load inertia adjusting devices with the same structure and a laser speed measuring instrument with a speed measuring reflective sticker are arranged on the rotating disc. The application can experiment the knowledge of classical control theory, and can also actively change the rotational inertia of the load, so as to facilitate the research on the tracking effect of the DC motor feedback speed regulation when the rotational inertia is changed.

The application relates to the field of soil desalination, and particularly discloses a power-on method and a power-on device for soil desalination. The device comprises a power supply, a plurality of current distributors and a plurality of electrode groups. The method comprises the following steps: device preparation; single round power-on: according to the size of the detection current of each group, the distance between the positive and negative electrodes of power-on is adjusted; multiple rounds of power-on: the initial power-on positive and negative electrode spacing of the next round of power-on is smaller than that of the previous round of power-on. According to the change of the current with time in the electric desalination process, the distance between the electrodes is adjusted to realize the adjustment of the current, the electric desalination process is kept under suitable current conditions at all times, the desalination efficiency is improved, the desalination time is shortened, the waste of electric energy is reduced, and the energy consumption is reduced. Compared with the mode of adjusting the voltage by using a variable voltage power supply, the power-on method provided by the application adopts a constant voltage direct current power supply, and a power supply with continuously adjustable voltage is not needed, so that the cost of the power supply is reduced.