Ten Daily Electronic Common Sense-Section 27

What is the initial MAC address used for?

The initial MAC address is configured on the virtual network adapter in the VM. This is determined by vSphere when the vNIC is created, or manually by changing the value provided by vSphere. This is very similar to “burning” the MAC address (BIA) of a physical network card.

What are the precautions for using MOS field effect transistors?

Precautions for the use of MOS field effect transistors: MOS field effect transistors should be classified when they are used and cannot be interchanged at will. Due to the high input impedance of MOS field effect transistors (including MOS integrated circuits), it is very easy to be broken down by static electricity. The following rules should be paid attention to when using: 1. MOS devices are usually packed in black conductive foam plastic bags when leaving the factory, and do not take them casually. in a plastic bag. You can also use thin copper wires to connect the pins together, or wrap them with tin foil. 2. The removed MOS device cannot slide on the plastic board, and a metal plate should be used to hold the device to be used. 3. The soldering iron used for welding must be well grounded. 4. Before welding, the power line of the circuit board should be short-circuited with the ground wire, and then the MOS device should be separated after the welding is completed. 5. The welding sequence of each pin of the MOS device is drain, source, and gate. The order of disassembly is reversed. 6. Before the circuit board is installed, touch each terminal of the machine with a grounded wire clip, and then connect the circuit board. 7. The gate of the MOS field effect transistor is preferably connected to a protection diode under the allowable conditions. When overhauling the circuit, attention should be paid to check whether the original protection diode is damaged.

In the MOST network system, what are the two types of nodes from the perspective of synchronization?

One is the timing master node that sends the frame format; the other is the slave node, which is synchronized with the clock master node.

What is the working principle of the geomagnetic sensor?

The geomagnetic field sensor determines the direction of the car by sensing the earth’s magnetic field.

What are the main features of the 82C250?

1. Fully compatible with the ISO 11898 standard;
2. High speed (up to 1 Mb/s);
3. With the ability to resist instantaneous interference in the automotive environment and protect the bus;
4. Slope control (Slope Contr01), Reduce radio frequency interference (RFI);
5. Overheat protection;
6. Prevent battery-to-ground short circuits in 24 V systems;
7. Low current standby mode;
8. Nodes will not interfere with the bus when not powered on;
9. The bus can connect at least 110 nodes.

What is the circuit of the capacitance micrometer?

The whole circuit of the capacitance micrometer includes: high gain main amplifier (including preamplifier), precision rectifier circuit, vibration measuring circuit and high stability (±24 V) regulated power supply.

What is the ADSP21160 power supply solution?

• Power supply scheme for single-chip ADSP21160 working
• Power supply scheme for multi-chip ADSP21160

What are the main factors determining the performance of WOLED?

The performance of WOLED is mainly determined by factors such as the properties of light-emitting materials, carrier injection mode and transmission efficiency, exciton generation efficiency, and light output coupling efficiency.

What are the requirements for 0LED for conductive glass?

The flatness of IT0 is first required to ensure complete contact between the IT0 electrode and the organic layer. In addition, the resistivity should be small, and the sheet resistance is preferably less than 10 彤, to ensure that the power consumed on the ITO electrode is not too large in a high-resolution device.

Considerations for using CMOS Integrated Circuits(ICs)s:

CMOS integrated circuits should not be installed or removed while the power is on. For all processes in contact with CMOS integrated circuits, the workbench and floor used are strictly prohibited from laying high-insulation boards (such as rubber sheets, glass sheets, plexiglass, glue boards, etc.), and a strictly grounded fine wire mesh should be laid on the workbench. or copper wire mesh, and frequently check the grounding reliability.
Testing of CMOS integrated circuits. All instruments and meters of CMOS integrated circuits should be well grounded during testing. If it is a low-impedance signal source, it should be ensured that the input signal does not exceed the power supply voltage range of the CMOS integrated circuit (CXXX series is 7~15V, C4000 series is 3~18V), that is, VSS≤Vi≤VDD. If the input signal must exceed CMOS For the power supply voltage range of the integrated circuit, a current limiting resistor should be added to the input end so that the input current does not exceed 5mA to avoid burning the protection diode inside the CMOS integrated circuit. If the signal source and the CMOS integrated circuit use two sets of power supplies, when starting up, the CMOS integrated circuit power supply should be connected first, and then the signal source power supply should be connected.
Mounting of CMOS integrated circuits. In order to avoid damage to the circuit due to electrostatic induction, the soldering iron used for soldering CMOS integrated circuits must be well grounded, and the soldering time should not exceed 5 seconds. It is best to use a 20~25W internal heating electric soldering iron and 502 epoxy flux, and a socket can be used if necessary. When switching, the power supply and load capacity should be considered. In addition, for those CMOS integrated circuits with different package forms and pin arrangements, they generally cannot be directly replaced. If it needs to be replaced, some corresponding transformations should be made to make the two terminals with the same function correspond one-to-one. When shutting down, turn off the power of the signal source first, and then turn off the power of the CMOS integrated circuit.
Protection measures for CMOS integrated circuits. Because the input impedance of CMOS integrated circuits is extremely high, random electrostatic accumulation is likely to cause the voltage at any two ends of the circuit terminal to exceed the MOS transistor gate breakdown voltage, thereby causing circuit damage. Therefore, when the CMOS integrated circuit is not in use, all the outer leads of the circuit should be short-circuited, or placed in a conductive shielding container to prevent electrostatic breakdown.
Interchange of CMOS integrated circuits. In use, some CMOS integrated circuits can be directly replaced. For example, the domestic CC4000 can be directly replaced with the foreign products CD4000 and MC14000 series. For those CMOS integrated circuits whose pin arrangement and package form are exactly the same, but the electrical parameters are different, great care should be taken when switching them. For example, there are some varieties of domestic CC4000 and CXXX, their working voltage is different, CC4000 is 3~18V, CXXX is 7~15V.