Abstract: A water level control method of an air conditioner and the air conditioner are provided. The air conditioner includes a first fan, a condenser, a compressor, a water tank, a rotating wheel, and a motor. The first fan is configured to dissipate heat from the condenser and the compressor. The motor is configured to drive the rotating wheel to rotate, so as to spray condensed water in the water tank onto the condenser. The method includes: if a water level of the condensed water reaches a first preset water level, controlling the first fan to operate at a minimum rotational speed and the motor to operate at a maximum rotational speed, and obtaining a condenser temperature, and controlling at least one of a rotational speed of the first fan, a rotational speed of the motor, or an operating frequency of the compressor according to the condenser temperature.

Abstract: The invention discloses an active vibration or sound absorption method with virtual resonators exclusively using sensing electromagnetic coil's current and voltage. The invention includes an absorption actuator, a sensing module of coil's current and voltage, an absorption controller, and a driving module. The method controls the coil current's phase to be orthogonal to the actuator velocity's phase, to adjust the resonant frequency of the actuator, such that the signal to be absorbed causes a resonance in the actuator. In this way, a virtual resonator is formed. Moreover, one actuator can generate multiple virtual resonators simultaneously to absorb energy of multiple signals with different frequencies, and the resonant frequency and its damping ratio for each virtual resonator can be adjusted independently.

Abstract: This invention provides a noise absorption method and device with an adjustable conical shaped annular aperture on a Helmholtz resonator composed of a Helmholtz resonant cavity, a resonance control package, a sensing & actuating modules and a controller. The resonant cavity harvests noise energy by tracking of the noise resonance frequency which is achieved by adjusting the aperture openness between a movable conical shell and the resonant cavity according to a resonance control algorithm of combination of FFT (Fourier Fast Transform) adjustment and PLL (Phase-Locked Loop control) adjustment. Meanwhile, the controller applies a driving current into a coil attached to the movable conical shell based on DXHS (Delayed-X Harmonic Synthesizer) algorithm, so that harvested noise energy on the movable conical shell can be absorbed with maximum efficiency. Additionally, a part of the noise energy is dissipated by resonant air friction flowing through the annular aperture on the cavity.

Abstract: Provided an active suppression controller with an adaptive algorithm capable of tracking the fluctuation of multi-fundamental frequencies and correcting them while the deviation is divergence based on the DXHS (Delayed-X Harmonics Synthesizer). It includes a controller's architecture, an adaptive frequency tracking & correcting algorithm and its FPGA implementation structure in real-time.