Ten Daily Electronic Common Sense-Section 88

What is the control channel used for?What can be divided?

Control channels are used to carry signaling or synchronization data. It can be divided into broadcast channel, common control channel and dedicated control channel.

How to measure the quality of the triode？

1. Check the two PN junctions of the triode. We take the PNP tube as an example to illustrate. The structure of a PNP-type triode is equivalent to two diodes, and the negative electrodes are connected together by the negative electrodes. We first use a multimeter R×100 or R×1K to measure the forward and reverse resistance between e and b and between e and c. When the red test lead is connected to b, use the black test lead to connect e and c respectively, and the resistance value should be small twice. Then change the red test pen connected to b to a black test pen, and then use the red test pen to connect e and c respectively. There will be two cases where the resistance value is large. The tested triode conforms to the above conditions, indicating that this triode is good.
2. Check the penetration current of the triode: We call the reverse resistance between the triodes c and e as the penetration current. Connect the red test lead of the multimeter to the collector c of the PNP transistor, and the black test lead to the emitter e, and see the indicated value of the watch. This resistance value should generally be greater than a few thousand ohms, the larger the better and the smaller, the worse the stability of the transistor.
3. Measure the amplification performance of the triode: use the test leads to connect the c and e of the triode to see the indicated value of the multimeter. Then connect a 50–100K resistor between c and b to see how much the pointer swings to the right. The larger the swing, the higher the magnification of the tube. The external resistance can also be replaced by human body resistance, that is, pinch b and c by hand.

What peripheral register space is included in the register map?

Peripheral Architecture 0: Peripherals that map directly to the CPU memory bus.
Peripheral Architecture 1: Peripherals mapped to the 32-bit peripheral bus.
Peripheral Architecture 2: Peripherals mapped to the 16-bit peripheral bus.

What are the characteristics of PID control?

PID control has become one of the main technologies of industrial control because of its simple structure, good stability, reliable operation and convenient adjustment.
PID control, also known as PID regulation, is proportional calculus control. It is composed of the advantages of Pl control and PD control.

What is the hierarchical structure of the frame memory?

The frame memory of each preview output port (P-port) and video codec port (C-port) includes 4 ping-pong memories.
The Ping-pong memory contains three storage elements: luminance Y, chrominance Cb, and chrominance Cr.

What is infrared data transmission?

IrDA (Infrared Data Association) was originally the abbreviation of Infrared Data Association and also used as the abbreviation of Infrared Standard.
IrDA is a technology that utilizes infrared light for point-to-point communication and is the first technology to implement a personal area network (PAN).

In order to ensure the stable and safe operation of the system and minimize the loss caused by the fault, what are the protection measures of the control system?

1. Protection measures taken by the CPLD chip in the optical fiber board
2. Protection measures in the CPLD of the control board
3. Problems and solutions encountered in practice

What are the performance indicators of automotive sensors?

Accuracy index, responsiveness, reliability, durability, compactness, adaptability, output level and manufacturing cost, etc.

What is a directional connection point?

When the vertical shaft is oriented, it is the measuring point that is connected to the casting point hammer line for measurement.

What is the head of the multimeter according to the working principle?

Commonly used ammeters and voltmeters are divided into two types: magnetoelectric type and electromagnetic type according to their working principles:
Magnetoelectric instruments are used to measure DC current and DC voltage.
Multi-purpose electromagnetic instrument for measuring AC current and AC voltage.