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    What are the scheduling principles for the priority of the task?

    Interruption relevance; urgency; criticality; frequency; swiftness; transitivity.

    What stages of charging process does BQTINY-11 support?

    The BQTINY-11 supports a three-stage charging procedure. It includes a pre-charging adjustment stage, a constant-current charging stage, and a high-precision constant-voltage charging stage required by many device manufacturers.

    What are the types of photoelectric sensors?

    • The first type of photoelectric sensor measurement system converts the measurand into a continuously changing photocurrent, which has a single-value correspondence with the measurand.
    • The second type of photoelectric sensor measurement system is to convert the measured into intermittently changing photocurrent, and the system output is an electrical signal of switching value.

    Among the vibrating wire sensors currently used, what kinds of vibrating wire clamping devices are there?

    1. Pin-type clamping device
    2. Conical bolt clamping device
    3. Scissor clamping device

    What three functions are provided by the power management system?

    The power management system provides 3 functions: monitoring, control and configuration.

    What are the main parameters of the Clock to Clock tab?

    The Clock to Clock tab mainly has three parameter fields: From Clock Edge, To Clock Edge and Delay(ns).

    What are the characteristics of micro sensors?

    High signal-to-noise ratio, high sensitivity, miniaturization and low cost.

    What are the functions of the Digital Comparison (DC) module?

    By the analog comparator (COMP) module output signal, the DCAH/DCAL and DCBH/DCBL signal trigger events can either be filtered or directly fed back to the trigger area, event trigger and time base (TB) modules. Event filtering (clearing the blanking window logic ) can choose to clear the input signal or remove interfering noise.

    What is the trend of logic analyzers?

    The basic development trend of logic analyzers is the continuous integration of computers and instruments. Using Windows on a PC platform, given the correct software and related tools, remote control over the Internet is possible. Source code and symbols are extracted from the object file format, and the processor can run various control operations. The development of technology also gradually integrates the functions of the oscilloscope and the logic analyzer into a hybrid instrument (MSO), also known as a mixed signal test instrument.

    What is a photoelectric encoder?

    Working principle: When the shaft of the photoelectric encoder rotates, both lines A and B generate pulse output, and the two-phase pulses of A and B differ by 90 degrees in phase angle. From this, the rotation direction of the photoelectric encoder and the speed of the motor can be measured.
    If the A-phase pulse is ahead of the B-phase pulse, the photoelectric encoder is forward rotation, otherwise it is reverse rotation. The Z line is a zero pulse line, and the photoelectric encoder generates a pulse every time it rotates, which is mainly used for counting. Line A is used to measure the number of pulses, and line B and line A can be used to measure the direction of rotation. N is the motor speed Δn = ND measurement – ND theory. For example: the speed of our car is 1.5m/s, the diameter of the wheels is 220mm, C=DPi, and the motor is controlled at 21.7 rpm. According to the index of the servo system, the motor speed is set to 1500 rpm, so when ND=21.760=130 rpm, the number of pulses output by the optical encoder per second is: PD=130×600/60 = 1300 pulses.
    When the measured number of pulses deviates from the calculated standard value, the incremental voltage △U output to the servo system can be calculated according to the corresponding relationship between the voltage and the number of pulses. After D/A conversion, the number of incremental pulses is calculated and then subtracted. When the running time is longer and the route is longer, the deviation from our pre-made route is more. At this time, the system starts the position loop, by continuously measuring the number of pulses output by the photoelectric encoder per second, and comparing it with the standard value PD (ideal value). Calculate the increment ΔP and convert it into the corresponding D/A output digital quantity, reduce the number of pulses of the input motor through the controller, and subtract the increment from the original output voltage, forcing the motor speed to decrease, When the measured ΔP is close to zero, the adjustment is stopped, so that the motor speed can always be controlled within the allowable range. According to the detection principle, the encoder can be divided into optical, magnetic, inductive and capacitive. According to its scale method and signal output form, it can be divided into three types: incremental, absolute and hybrid.
    1.1 Incremental encoder: The incremental encoder directly uses the photoelectric conversion principle to output three groups of square wave pulses A, B and Z phases. The phase difference between the two groups of pulses A and B is 90 degrees, which is one pulse per revolution, which is used for reference point positioning. It has the advantages of simple principle structure, average mechanical life of more than tens of thousands of hours, strong anti-interference ability, high reliability, and is suitable for long-distance transmission. The disadvantage is that the absolute position information of the shaft rotation cannot be output.
    1.2 Absolute encoder: The absolute encoder is a sensor that directly outputs digital quantities, and there are several concentric code tracks along the radial direction on its circular code disc. Each track is composed of light-transmitting and opaque sectors alternately, and the number of sectors of adjacent code tracks is doubled. The number of code tracks on the code disc is the number of bits of its binary numbers. One side of the code disc is the light source, and the other side corresponds to each code track with a photosensitive element. When the code disc is in different positions, each photosensitive element converts the corresponding level signal according to whether it is illuminated or not to form a binary number. The characteristic of this encoder is that it does not need a counter, and a fixed digital code corresponding to the position can be read out at any position of the rotating shaft. Obviously, the more code channels, the higher the resolution. For an encoder with N-bit binary resolution, its code disc must have N code tracks. At present, there are 16-bit absolute encoder products in China. Absolute encoders use natural binary or cyclic binary (Gray code) for photoelectric conversion. The difference between an absolute encoder and an incremental encoder lies in the light-transmitting and opaque line patterns on the disc. The absolute encoder can have several codes, and the absolute position is detected according to the code on the readout code disc. The design of the encoding can use binary code, cyclic code, two’s complement code and so on. Its characteristics are: 1.2.1 The absolute value of the angle coordinates can be read out directly; 1.2.2 There is no accumulated error; 1.2.3 The position information will not be lost after the power is cut off. However, the resolution is determined by the number of bits in the binary, that is to say, the precision depends on the number of bits. Currently, there are 10 bits, 14 bits and so on.
    1.3 Hybrid absolute value encoder: Hybrid absolute value encoder, which outputs two sets of information. A set of information is used to detect the magnetic pole position, with absolute information function. The other group is exactly the same as the output information of the incremental encoder. The photoelectric encoder is an angle (angular velocity) detection device that will input the amount of angle to the shaft. Using the principle of photoelectric conversion to convert into corresponding electrical pulses or digital quantities, it has the advantages of small size, high precision, reliable operation, and digital interface. It is widely used in CNC machine tools, rotary tables, servo drives, robots, radars, military target determination and other devices and equipment that need to detect angles.


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