Abstract: An EDFA may include an input photodiode configured to generate a control signal based on an input signal. The EDFA may include a blind stage configured to generate an amplified signal based on the control signal and the input signal. The EDFA may include a non-blind stage configured to generate an output signal based on the amplified signal within the blind stage, the control signal, and a feedback signal. The EDFA may include a filter configured to generate a filtered signal based on the output signal. The EDFA may include an output photodiode configured to generate the feedback signal based on the filtered signal. The EDFA may include an alarm device. A signal within the non-blind stage may be generated based on the feedback signal and the control signal. The alarm device may be configured to generate an alarm signal when the signal exceeds a threshold value.

Abstract: An EDFA may include an input photodiode configured to generate a control signal based on an input signal. The EDFA may include a blind stage configured to generate an amplified signal based on the control signal and the input signal. The EDFA may include a non-blind stage configured to generate an output signal based on the amplified signal within the blind stage, the control signal, and a feedback signal. The EDFA may include a filter configured to generate a filtered signal based on the output signal. The EDFA may include an output photodiode configured to generate the feedback signal based on the filtered signal. The EDFA may include an alarm device. A signal within the non-blind stage may be generated based on the feedback signal and the control signal. The alarm device may be configured to generate an alarm signal when the signal exceeds a threshold value.

Abstract: An EDFA may include an input photodiode configured to generate a control signal based on an input signal. The EDFA may include a blind stage configured to generate an amplified signal based on the control signal and the input signal. The EDFA may include a non-blind stage configured to generate an output signal based on the amplified signal within the blind stage, the control signal, and a feedback signal. The EDFA may include a filter configured to generate a filtered signal based on the output signal. The EDFA may include an output photodiode configured to generate the feedback signal based on the filtered signal. The EDFA may include an alarm device. A signal within the non-blind stage may be generated based on the feedback signal and the control signal. The alarm device may be configured to generate an alarm signal when the signal exceeds a threshold value.

Abstract: A rotary compressor (700) and a refrigeration cycle device (1000) having same are provided. The rotary compressor comprises: a liquid reservoir (1), a first direction control assembly (49), and a compression mechanism.

Abstract: A compression device includes an air cylinder (31); an upper bearing (4) and a lower bearing (5); a piston (71) which defines a working space; a first slide vane (81) and a second slide vane (82) which separate the working space into a first and a second working chamber; a first air suction port (101) and a second air suction port (102) both of which are in communication with the working space; and a first air discharge port (91) and a second air discharge port (92) both of which are in communication with the working space. The first and the second air suction port satisfy the following condition: 0.25?(V1/S1)*(S2/V2)?4, where VI and V2 are respectively the maximum volume of the first and the second working chamber, and S1 and S2 are respectively the opening area of the first and the second air suction port.

Abstract: A refrigeration cycle device and a two-stage rotary compressor thereof. The two-stage rotary compressor includes a housing with a gas injection chamber and two cylinders disposed therein; the gas injection chamber connected to a liquid reservoir disposed outside of the housing and a gas injection pipe; a first cylinder in communication with the gas injection chamber; a second cylinder connected to the liquid reservoir, and having a sliding vane groove and a compression chamber with a piston disposed therein in communication with the gas injection chamber; a sliding vane, received in the sliding vane groove when the gas injection chamber is in communication with the liquid reservoir, with an outer end and the sliding vane groove defining a backpressure chamber in communication with the gas injection chamber; and with an inner end abutting against the piston when the gas injection chamber is in communication with the gas injection pipe.

Abstract: The present disclosure provides a method and a device for controlling a power factor on motor side and a system having the same, and the method includes: controlling the motor using a control approach of Id?=0 so as to obtain quadrature-axis voltage Uq? and direct-axis voltage Ud? in a virtual coordinate system of a current control cycle; calculating a first control value according to Uq? and Ud?; obtaining a power factor control target value, and calculating a target control value according to the power factor control target value; performing a PI control on a difference between the target control value and the first control value so as to obtain a coordinate deviation angle, and overlapping the coordinate deviation angle to a motor angle of the current control cycle so as to build a virtual coordinate system of a next control cycle, such that the power factor on the motor side is controllable.

Abstract: The present disclosure provides a method and a device for controlling a power factor on motor side and a system having the same, and the method includes: controlling the motor using a control approach of Id?=0 so as to obtain quadrature-axis voltage Uq? and direct-axis voltage Ud? in a virtual coordinate system of a current control cycle; calculating a first control value according to Uq? and Ud?; obtaining a power factor control target value, and calculating a target control value according to the power factor control target value; performing a PI control on a difference between the target control value and the first control value so as to obtain a coordinate deviation angle, and overlapping the coordinate deviation angle to a motor angle of the current control cycle so as to build a virtual coordinate system of a next control cycle, such that the power factor on the motor side is controllable.

Abstract: A rotary compressor (700) and a refrigeration cycle device (1000) having same are provided. The rotary compressor comprises: a liquid reservoir (1), a first direction control assembly (49), and a compression mechanism.

Abstract: A refrigeration cycle device and a two-stage rotary compressor thereof. The two-stage rotary compressor includes a housing with a gas injection chamber and two cylinders disposed therein; the gas injection chamber connected to a liquid reservoir disposed outside of the housing and a gas injection pipe; a first cylinder in communication with the gas injection chamber; a second cylinder connected to the liquid reservoir, and having a sliding vane groove and a compression chamber with a piston disposed therein in communication with the gas injection chamber; a sliding vane, received in the sliding vane groove when the gas injection chamber is in communication with the liquid reservoir, with an outer end and the sliding vane groove defining a backpressure chamber in communication with the gas injection chamber; and with an inner end abutting against the piston when the gas injection chamber is in communication with the gas injection pipe.

Abstract: A compression device includes an air cylinder (31); an upper bearing (4) and a lower bearing (5); a piston (71) which defines a working space; a first slide vane (81) and a second slide vane (82) which separate the working space into a first and a second working chamber; a first air suction port (101) and a second air suction port (102) both of which are in communication with the working space; and a first air discharge port (91) and a second air discharge port (92) both of which are in communication with the working space. The first and the second air suction port satisfy the following condition: 0.25?(V1/S1)*(S2/V2)?4, where V1 and V2 are respectively the maximum volume of the first and the second working chamber, and S1 and S2 are respectively the opening area of the first and the second air suction port.

Abstract: The present invention discloses an injection molding device for wrapping wires with three-color spiral insulation layers and three-color wires. The injection molding device comprises: a spinning block, a fixed mould, and a handpiece that are coaxially mounted. Each of the axes of these three components is provided with a center bore. The third plastic feeding pipe is arranged between the side wall of the handpiece and the center bore; a first plastic feeding pipe and a second plastic feeding pipe are arranged between the side wall of the fixed mould and the front end face thereof. This injection molding device is used to wrap wires up with three-color insulation layers. Three-color spiral wires are easy to identify and operate.