Ten Daily Electronic Common Sense-Section 93

How is the storage depth calculated?

Storage depth=sampling rate×scanning speed×10, that is, waveform observation time.

What are the functions of the body control module control electronics?

• Airbag deployment and vehicle flameout function.
• Unlock the lighting.
• Automatic door locking system.
• Automatic light off function.
• Automatic light on function.
• Battery saving mode.
• Dome light and door control light control system.
• Central locking system – remote control vehicle security system.
• Intrusion warning system.
• Instrument dimming control system.
• Ask the wiper control system.
• Power window system.
• Motorized antenna control system.
• Priority setting key to automatically apply two people’s personal vehicle settings.
• Rear lamp bulb failure indication.

How does the vacuum bellows intake pressure sensor work?

This manometer drives electronic sensors in response to pressure changes. The bellows of the bellows pressure gauge is welded from thin metal sheets. It is evacuated inside, and the outside is connected to the intake manifold. Changes in pressure outside the bellows cause it to expand and contract.

What is a superframe?

The concept of a superframe is a combination of a series of consecutive time slots. Superframes are periodic, whose period is the sum of a set of time slots.
All superframes in a WirelessHART network start at ASN 0, when the network is first created. Then, each superframe repeats cyclically according to its own time period.
In WirelessHART, a time slot communication is described by a phasor like this: {frame id, index, type, SrC addr, dst addr, channel offset}. Where frame id is a specifically defined superframe number. index is the slot position index in the superframe. type defines the type of slot (eg send/receive/idle). src addr and dst addr are the source device address and destination device address, respectively. Channel offset provides a logical channel for communication.
In order to support the channel hopping function, each device needs to maintain a valid channel table. Due to the blacklist, the actual number of this table may be less than 16.

The interference of automobile electromagnetic equipment to ECU is generally entered in the form of pulse. What are the main points of anti-interference measures?

1. Eliminate power supply voltage fluctuation interference.
2. Eliminate grounding system interference.
3. Eliminate process channel and space interference.

What is the physical layer?

WirelessHART physical layer is basically based on IEEE 802.15.4-2006 2.4GHz DSSS physical layer. This layer defines RF characteristics such as signal pattern, signal strength and device sensitivity.
Just like IEEE802.15.4 standard, WirelessHART works in the free ISM frequency band of 2400- 2483.5MHz, and its data transmission rate can be as high as 250kbit/s. The frequency band is divided into 16 channels and numbered 1 1 to 26, and the frequency spacing between two adjacent channels is 5MHz.

A coexistence test might include those projects?

1. Signal reception strength.
2. Transmission range.
3. As the test target of the interference source or the interfered person.
4. Traffic model.
5. Channel selection.
6. Frame length.
7. Antenna gain.
8. Path fading.

What is a sensor?

The definition of a sensor is: a device or device that can feel or respond to a prescribed measurement and convert it into a usable signal output according to a certain law.

Although the basic structure of the potentiometer is the same as that of the variable Resistors, there are differences in many aspects. What are the main points?

1. The operation mode of the potentiometer moving piece is different, and the potentiometer is equipped with a handle.
2. The resistance distribution characteristics of potentiometer resistors are different from those of variable resistors. The distribution characteristics of potentiometer resistors with various output function characteristics are different.
3. Potentiometers are multi-connected, and There is no variable resistor.
4. The potentiometer is large in size, firm in structure, and has a long life.

What are the two functions of the preamplifier of the piezoelectric sensor?

The preamplifier of the piezoelectric sensor includes two functions:
One is to amplify the weak electrical signal output by the sensor.
The other is to transform the high output impedance of the piezoelectric sensor into a low output impedance.