320 results about "Automatic power control" patented technology

The invention discloses a full-automatic cementing complete set control method, and relates to the related technical field of petroleum equipment. The method comprises the steps of intelligent full-automatic cementing key control, matching control, an automatic power control system, a slurry mixing control system, an automatic premixing function, automatic liquid level control, automatic manifoldcontrol, a hydraulic pneumatic control system, a lime supply automatic control system, a chemical additive automatic control system, a water supply automatic control system and a well control device automatic control system. According to the operating method, intelligent full-automatic control over cementing operation is achieved, and breakthrough of the automatic manifold control technology is achieved successfully; through the lime supply automatic control technology and the full-automatic control technology, the advanced level of equipment and technologies of the company is improved greatly; a new mode of future cementing operation is created, and a new era of a smart oil field is started; through achievement of the intelligent full-automatic cementing operation technology, the problems, that customers face at present, of shortage of labor forces and labor resources can be solved; and the intelligent operation is achieved.

A low-noise laser diode module comprises a laser diode for emitting light with a wavelength in the range from UV to IR, a drive circuit for injecting electrical current into said diode, and an automatic power control circuit for monitoring and adjusting laser output power using front-facet photodiode external to the laser assembly and a feedback loop. Said drive circuit produces injection current modulated by an RF signal with variable degrees, depending on the wavelength to be stabilized, the desired spectral bandwidths of the laser output, and/or other applications. Said RF signal can be a sine wave, a distorted sine wave, a rectified sine wave, a non-sine wave, a series of narrow pulses, or repetitive shunt. The present invention encompasses a method for producing stable, broadband, and low-coherent laser. The present invention also encompasses a method for producing stable narrowband or single longitudinal mode laser. The present invention further encompasses a compact light source applicable to DPSS lasers, fiber lasers, optical parametric oscillators, low-speckle laser display systems, and seeders, with or without nonlinear frequency conversion processes.

System and method for automatic control of processes or application, such as the activation or deactivation of a radiation source for medical purposes. The system comprises an operator tracking system arranged to determine the gesture/posture of a user, an evaluation device arranged to evaluate the determined gesture/posture, and an enabling device arranged to enable and disable the radiation source in response to an output of the evaluation device. The operator tracking system may use a gazing direction analysis that may be based on the output of an eye tracking system, or an emitter-receiver arrangement for a directed signal.

An efficient and low-noise solid-state laser is optically pumped by one or more laser diode(s) driven by RF modulated current. The solid-state laser operation is stabilized by the pump source stable in both spectrum and intensity, in conjunction with automatic power control wherein the feedback loop accurately reflects the true drift in the output power. Moreover, the pump efficiency is optimized and the optical noise is minimized by adjusting the diode operation temperature such that the pump wavelength coincides with the absorption peak of the gain medium. By internally or externally modulating the amplitude of the drive current, the pump diode(s) operate in pulsed mode with controllable shape, width, repetition rate, and pulse-to-pulse intervals, which enables essentially constant optical energy produced from each pulse of the solid-state laser in high repetition rates with variable pulse-to-pulse intervals.

An automatic power control system provides a control signal that regulates the output power of at least one laser diode. Coarse adjustment of the control signal is provided by a first means, preferably a digital variable resistor, while fine adjustment and compensation is provided by a second means, preferably by a digital-to-analog converter that receives an input signal proportional to a sensed control system parameter. The control system includes an operational amplifier having a first input coupled to sense output power, and a second input coupled to a DAC to provide finer resolution control. Memory can store system parameter or system parameter variations that can be coupled to the DAC and/or variable resistor to enhance system stability over ambient variations.

A power control system and method for a wireless telephone employs an open loop technique for relatively low power levels and a closed loop technique at higher power levels. In the open loop technique, a wireless telephone (104, 106, 108) stores a phasing table of automatic power control (APC) values for the power levels (which are used to control upconverter gain levels measured at different channels. In operation, a power controller (322) reads the power level and reads the APC value in the table. Another table stores the APC value for one power level as the channel and temperature are varied. This value is interpolated, as needed, during operation. The APC value for the open loop approach is determined by reading the input channel; finding the closest higher and closest lower channels in the temperature-channel table; interpolating between APC values for the temperature column of the closest lower temperature, to get the actual value. The difference between this value and the APC value for the actual power level in the phasing table is then obtained.

This invention relates to a power and temperature automatic control device of a pump laser including an automatic power control circuit and an automatic temperature control circuit, the two of which apply a pulse-width modulation way to drive the pump laser and a freezer separately so as to realize automatic temperature and power controls of the pump laser, which reduces the power loss and volume of its controller greatly. The device is controlled by a single-chip processor, which sets and fetches various parameters.

The present invention discloses a method for debugging the average optical power and extinction ratio parameter of optical transmitter. The optical transmitter is set to an automatic power control mode. The modulation signal coupling mode of the laser driving chip of light transmitter and the laser is set to a direct-current coupling mode. A microcomputer tests the luminous efficiency and threshold current of laser of the optical transmitter. The microcomputer debugs the average optical power of optical transmitter to a preset average optical power area. The microcomputer debugs the present extinction ratio of optical transmitter to a preset extinction range. The technical scheme according to the invention can greatly reduce the investment of product line on the device and has the advantages of automatic debugging realization, reduced production cost and increased production efficiency.

The invention discloses a method for modeling an automatic power generating control model in power system stimulation, which models an automatic power generating control system by considering the control mode and the control performance evaluation standards in the automatic power generating control and the algorithm characteristics of power system stimulation. Meanwhile the invention discloses a method for implementing an automatic power control model in power system stimulation. The model can stimulate the three modes of constant-frequency control, constant-exchange power control and tie-line power and frequency deviation control in automatic power generating control, and simultaneously achieves the three control performance evaluation standards of A1/A2, CPS1/CPS2 and T of automatic power generating control; regions adopt different control strategies according to different region control performance evaluation standards, so that the model can analyze the influence of automatic power generating control in the long-term dynamic stimulation in a power system, and the requirement of the simulation of of the whole process of electromechanical transient and electromechanical medium and long-term dynamic state of the power system are met.

A laser diode device of package not greater than 5.6 mm, having an automatic power control circuit directly mounted in a heat sink (or a submount) inside the metal cap thereof to substitute for an external circuit board for driving by voltage instead of current.

The invention relates to a method for implementing automatic power control based on power detection in an optical network. It monitors and regulates the power of all the corresponding nodes in a power control link according to the standard power value provided by the given reference standard, so as to meet the transmitting needs of the optical network and can implement full auto power control on the condition without any artificial interference. Therefore, it can make the power control link in the optical network possess a better self-adapting ability and maintain stable transmitting property in the allowable power change range of the system. It can clearly grasp the power condition of each node in the whole power control link and is convenient for system maintenance and trouble clearing.

Disclosed is a surface emitting laser device with a monolithically integrated monitor photodetector, which is combined with an automatic power control circuit, thereby being capable of more accurately controlling the surface emitting laser output power. A method is also disclosed, which is adapted to fabricate the surface emitting laser device. In accordance with, the present invention, the surface emitting laser device includes insulating layers each sandwiched between an intrinsic semiconductor layer and a doped semiconductor layer in a monitor photodetector adapted to partially absorb light emitted from a surface emitting laser, thereby outputting a detect signal for the light. The insulating layers serve to remove photocurrent resulting from spontaneous emission light emitted from the surface emitting laser. By this configuration, it is possible to accurately control the power of light emitted from the surface emitting laser through a laser window.

A control method for a laser diode is conducted such that optical output and OMA (optical modulation amplitude) or extinction ratio of the laser diode are controlled while modulating the optical output of the laser diode by applying a bias current and a modulation current to the laser diode. The method has: a first step of measuring the optical output of the laser diode; a second step of measuring a slope efficiency or a corresponding value of the slope efficiency while conducting APC (automatic power control) to adjust the bias current such that the optical output coincides with a predetermined value; and a third step of adjusting the modulation current by AAC (automatic amplitude control) according to the slope efficiency or the corresponding value of the slope efficiency such that the OMA or extinction ratio coincides with a predetermined value.

This invention provides an automatic power control (APC) circuit for keeping an extinction ratio constant even when the efficiency of a laser diode (LD) deteriorates. The APC circuit according to this invention stores first control data for deciding the relationship between a bias current Ib and a modulation current Im so that the extinction ratio under a certain target power is a predetermined value. A central processing unit (CPU) decides the bias current Ib and modulation current Im on the basis of a current optical output power and the first control data and supplies them to an LD driver. The APC circuit also stores second control data for deciding the correction value for the optical output power corresponding to the temperature of the LD. The CPU acquires the current temperature before deciding the bias current Ib, decides a correction value corresponding to the current temperature according to the second control data, and corrects the target power. Thereafter, the CPU computes the bias current Ib on the basis of the corrected target power.