Ten Daily Electronic Common Sense-Section 146

What are the common VHDL statements?

VHDL commonly used statements are divided into two types: parallel (Concurrent) statements and sequential (Sequential) statements.

What is a semiconductor optoelectronic device?

Do you know what is a semiconductor optoelectronic device?
When you pick up the phone and talk with friends far away in the sky, exchanging many important and unimportant news. When you turn on your computer to surf the Internet and greedily suck all kinds of valuable and worthless information, semiconductor lasers, detectors, modulators, and optical amplifiers are silently acting as faithful messengers for you. When you put the disc into various machines, semiconductor lasers and detectors are taking out the information on that plastic disc as your hard-working servants. Turn it into the movies, music and other things you want to enjoy.
The artificial satellite travels in space, the semiconductor infrared detector is its clairvoyance, and the semiconductor solar cell provides it with inexhaustible energy.
The colorful world in front of our eyes also has a contribution to semiconductor light-emitting diodes. The large family of semiconductor optoelectronic devices contains many members. Some of them can turn electricity into light, and some can turn light into electricity. Others can perform various processing and amplification on optical and electrical signals.
The operating wavelength of a semiconductor optoelectronic device is related to the type of semiconductor material used to make the device. There are conduction band and valence band in semiconductor materials, and electrons can move freely on the conduction band. Under the valence band, holes can move freely, and there is a forbidden band between the conduction band and the valence band.
When the electron absorbs the energy of light and jumps from the valence band to the conduction band, it turns the energy of light into electricity. The electrons with electrical energy jump back from the conduction band to the valence band, and can turn the electrical energy into light. At this time, the width of the forbidden band of the material determines the operating wavelength of the optoelectronic device.
The development of material science enables us to use energy band engineering to carry out various delicate tailoring of the energy bands of semiconductor materials. It can meet our various needs and do more things for us, and also enable the working wavelength of semiconductor optoelectronic devices to break through the limitation of the band gap of the material and expand to a wider range.

What are the principles for planning the IP address of an NE?

Each network element must have a unique IP address. Network elements can use standard A, B, and C class IP addresses.
An IP address must be used with a subnet mask. The core nodes and large PTN nodes on the backbone aggregation ring are configured as gateway network elements.
Two networks connected by Ethernet must be divided into different IP subnets. Prevent some network elements from being accessed by the network management system when the network is divided into regions.
The network segment where the IP addresses of all service ports in the network are located cannot overlap with the network segment where the management IP addresses of any NEs in the network are located.
The IP address of the non-gateway network element is recommended, and generally no manual configuration is required.

What are the main AC/DC drive power supplies?

EMI circuit, input rectification filter circuit, PFC circuit, power conversion circuit, PWM voltage regulation control circuit, output rectification filter circuit and protection circuit.

What is the role of the Bit Stream Processor (BSP)?

The bit stream processor completes the transmission control of the information bit stream between the sending buffer, RXFIF0 and CAN bus.
It also performs functions such as error detection, arbitration, bit stuffing, and error handling during control transfers.

What are the solutions to the FM radio microphone frequency drift problem with the 9018 triode?

The solution to the frequency drift problem of the FM wireless microphone made of 9018 triode:

1. Requirements for high-frequency circuits: the lead wire of the component should be as short as possible, and a large area should be grounded. You are lap soldering, the leads must be too long. And these too long line pins are an unstable distributed capacitance.
2. Disassemble the components and keep the lead wires clean. If there are sundries and stains such as welding oil, it will also cause instability.
3. The circuit board design and component installation position of the high-frequency circuit are very different from the audio circuit. Follow the above suggestions to modify it, it will be fine.

What are the advantages of barcodes?

1. The bar code is easy to make, and there is no special requirement for printing equipment and materials. Low cost and easy to popularize;
2. Bar code uses laser to read information, data input speed is fast, and identification is reliable and accurate;
3. The identification equipment has a simple structure and is easy to operate without special training.

What is an integrated temperature transmitter?

KHWB integrated temperature transmitter is a perfect combination of temperature sensor and transmitter, which converts the temperature signal in the range of -200~1600°C into a two-wire 4~20mADC electrical signal and transmits it to the display and adjustment in a very simple way. device, recorder, DCS, etc. Realize the precise measurement and control of temperature.
KHWB integrated temperature transmitter is an updated product of temperature measurement and control in modern industrial sites and scientific research institutes, and is an essential product for distribution systems and digital bus systems.
Features Ultra-small (module φ44×18) integration, strong versatility, two-wire 4~20mADC output. Long transmission distance, strong anti-interference ability. Cold junction, temperature drift, nonlinear automatic compensation. High measurement accuracy and good long-term stability. The interior of the temperature module adopts epoxy resin casting process, which is suitable for use in various harsh and dangerous places. Integrated design, simple and reasonable structure, can directly replace ordinary assembled thermocouples and thermal resistances. Mechanical protection IP65. The use of thermocouple temperature change can avoid the use of compensation wires and reduce costs. Various indication functions such as liquid crystals, digital tubes, and pointers are convenient for on-site timely monitoring. When the on-site ambient temperature is >70°C, the transmitter and on-site display instrument can be installed separately (isolated) Explosion-proof grade: dIIBT4, dIIBT5.
Protection level: IP54 technical index category SK-SBW modular temperature change SK-SBW integrated temperature change accuracy 0.2%F.S0.5%F.S Input thermocouple: B, S, T, K, J Thermal resistance: Pt100, Pt10, Cu100, Cu50 output two-wire system 4-20mADC operating temperature -25-85°C (0-60°C for integrated LCD meter) temperature influence ≤0.05%/°C humidity 5-95%RH on-site display no 31/2LED31/ 2LCD0-100% equal division scale display accuracy No digital type: 0.5 level Pointer type: 2.0 level Load capacity <600Ω (rated load 250Ω) Dimensions 44×1870×100 (repeater).
KHWB integrated temperature transmitter generally consists of a temperature measuring probe (thermocouple or thermal resistance sensor) and a two-wire solid electronic unit. The temperature measuring probe is directly installed in the junction box in the form of a solid module to form an integrated transmitter.
KHWB integrated temperature transmitter is generally divided into two types: thermal resistance and thermocouple type. The output of the KHWB integrated temperature transmitter is a unified 4-20mA signal; it can be matched with a microcomputer system or other conventional instruments. It can also be made into an explosion-proof or fire-proof measuring instrument upon user’s request.

What types of devices does the Quartus II software support?

Quartus II software supports many types of devices, mainly including StratixTM and Stratix Il, Stratix, CycloneTM, HardCopy, APEXTM II series, APEX II series, MercuryTM series, Flex lOk series, ExcaliburTM series, FLEX 6000 series, MAX II series, MAX 3000A series, MAX 7000 series and MAX 9000 series, etc.

What are the characteristics of lithium batteries?

Lithium batteries have the advantages of light weight, large capacity, and no memory effect.
The energy density of lithium batteries is very high, and its capacity is 1.5 times that of nickel metal hydride batteries of the same weight.