Ten Daily Electronic Common Sense-Section 129

What is the detection method of the photoelectric crank position sensor?

1. Unplug the sensor plug, turn on the ignition switch, and check that the voltage between the power terminal and the ground terminal on the plug should be 5v or 12V. If there is no voltage, you should check the voltage of the wire from the sensor to the ECU and the corresponding terminal on the ECU. If there is a voltage on the ECU terminal, the wire between the ECU and the sensor is broken; otherwise, the ECU is faulty.
2. Insert the sensor plug back, start the engine, and keep its speed at about 2500r/min. Measure the voltage of the output terminal of the sensor, the normal value is generally 2~3v. If the voltage is wrong, the sensor is damaged.
3. Use an oscilloscope to detect the waveform of the relevant signal to determine whether it is faulty.

What are the characteristics of the comfort system CAN bus?

1. The transmission rate is low, 100kbit/s.
2. The classification level is Class B of CAN bus.
3. Twisted pair transmission: CAN-H high level wire is orange/green, CAN-I. Low level wires are orange/brown.

Under what conditions can the charging and discharging process of a supercapacitor be performed?

1. Constant current;
2. Constant power;
3. Constant load.

What are the main research directions of some high-power tunable blue-green lasers?

1. Using a Nd:YVO4 laser with a working wavelength of 1342 nm, a green laser tunable from 503nm to 505nm can be produced after mixing the frequency of the pump and laser radiation in the KTP crystal cavity. When a Ti:Sapphire laser is used as the pump source, the tunable range of the laser can be increased to 22 nm.
2. Using an intracavity frequency doubler combined with an optically pumped semiconductor vertical external cavity surface emitting laser with an operating wavelength of about 976nm. By using lithium triborate (LBO) crystals, it is possible to generate a 1W continuous wave blue-green laser. The working wavelength is about 488nm, and the adjustable range is about 5nm.
3. Using the internal second harmonic to generate the resonant near-resonance radiated from the green pump, continuous wave and Mg-doped stoichiometric lithium tantalate as the nonlinear material single resonant optical parametric oscillator and 5mm BiB3O6 crystal Infrared signals can be implemented with a 450 mW CW single-frequency blue laser. Its tunable range is 425 nm to 489 nm, its line width is 8.5 MHz, and it has Gaussian spatial distribution of beams. It is speculated that a similar technique could produce a high-power tunable laser that could extend the spectral range from 300 nm to 700 nm.

What are the RFID source coding methods?

1. Reverse non-return-to-zero encoding
2. Manchester coding
3. Miller coding
4. Modified Miller Code

What are the basic functions of the reader?

1. Provide energy to the tag. When the tag is passive or semi-passive, the reader needs to provide energy to activate the electronic tag.
2. Realize the communication with the electronic tag. The reader/writer performs data access to the tag, including reading data and writing data to the electronic tag.
3. Realize communication with computer. The reader can use some interfaces to communicate with the computer and provide information to the computer. It is used for data exchange between the system terminal and the information management center, so as to solve the data management and information analysis needs of the entire system.
4. Realize identification of multiple electronic tags. The reader can correctly identify multiple electronic tags within its working range, has anti-collision function, and can exchange data with multiple electronic tags.
5. Realize moving target recognition. The reader can identify not only stationary objects, but also moving objects.
6. The reader must have the function of data recording. That is to record the data information that needs to be recorded in real time to meet the needs of the information center for further data analysis.

What different bit fields are the data frames composed of?

1. Start of frame (SOF)
2. Arbitration field
3. Control field
4. Data field
5. CRC field
6. Response field
7. End of frame

What are the components of the BlueZ kernel module?

The kernel module is composed of device driver layer, Bluetooth core layer, host control interface (HCI) layer, Bluetooth protocol core, logical link control and adaptation protocol (L2CAP), SCO audio layer and other related services.

What are the challenges that micro thermal management, thermal management and power management products can solve?

Miniature thermal management, thermal management and power management products address critical design challenges in next-generation products for the semiconductor, optoelectronics, consumer, automotive, industrial, medical and defense and aerospace industries.

What are the main features of traditional electronic system design methods?

1. Use Tongpeng’s logic components;
2. Simulation and debugging are carried out in the later stage of system design;
3. The main design document is the electrical schematic diagram.