In and out simulation: The test will swing a standard dummy buttocks at a certain Angle, rotate the dummy buttocks from the inside of the cushion to the outside, the buttocks rotation to the most outside is a cycle, a total of required number of cycles. The ventilation function should be intact after the test.
The original seats undergo rigorous testing, such as in the development of ventilation and heating systems, which need to be verified by multiple rounds of tests due to the risk of electrical components! --. For example, it has ventilationFunctional seats need to withstand 75 kg of simulated human buttocks in and out of the seat 50,000 times, in and out of 50,000 times, and durability tests under high and low temperatures. However, non-original modifications often lack long-term formal testing, and stability is difficult to guarantee! --.
Simulated human prosthetic hip 75kg gravity impact 100,000 times, twisting 30,000 times of the test 8 hours salt water immersion test 3 hours 80℃ high temperature 3 hours -40℃ low temperature test 5 cycle cycle test is through such fine production, and countless repeated trials to brew out the car easy so sophisticated products, making the car easy and easy'> Is radio knowledge systematically explained on the Internet? The effect of unwanted energy generated by a certain emission, radiation, induction or their combination on the reception of a radio communication system, so that the performance of the receiving effect is reduced, or the signal is not received, this effect is called interference. Interference according to its source can be divided into: industrial interference, celestial interference, cosmic interference, human interference and so on. In a radio communication system, an emission, radiation, or induction that is identified as producing interference.
Radio communication technology is a broad and in-depth field, "Radio Fundamentals (NoAs an authoritative textbook, "The Fourth Edition" introduces the basic knowledge of this field in detail. The book first explains the components of wireless communication system, including its basic components and signal transmission principles, to help readers understand the basic workflow of wireless communication.
Chapter 1: Radio Basics This book begins with a simple explanation of the birth and propagation of radio waves, laying the foundation for understanding the rest of the content. It elaborates the core principles of radio control, including the construction principles of measurement and control antenna, transmitting and receiving circuits. Chapters 2 to 8: Detailed Understanding of the System In these chapters, the reader will learn the commonly usedUnit circuits and integrated devices, such as actuator and control mechanisms.
Radio Receiving Skills and Techniques is a book that systematically introduces radio receiving skills.
1, a passive (referring to a linear time-invariant circuit without an independent power supply) containing inductors and capacitors under the action of an external power supply of a specific frequency, the phenomenon of pure resistance. This particular frequency is the resonant frequency of the circuit. The circuit with resonance as the main working state is called the resonant circuit. Radio installationThe harmonic circuit is used to complete the tuning, filtering and other functions. The power system needs to prevent resonance so as not to cause overcurrent and overvoltage.
2, frequency selection circuit generally use parallel resonant circuit, in the circuit of inductance and capacitor in parallel, when the capacitive reactance and inductive reactance of the capacitor at a certain frequency is just equal, its size precisely makes the voltage and current in the circuit in the same phase, at this time the circuit is pure resistance characteristics, the current in the circuit is the largest, This characteristic is used to select frequency in radio technology.
3, the broadcast is a fixed IF signal, in the working frequency range of the broadcast, through adjustmentThe local oscillator output frequency, frequency selection, when the input signal and the local oscillator mixing output to IF frequency frequency, then demodulation of IF signal, output audio signal.
The stronger the output power of the transmitter, the larger the coverage of the transmitted signal and the farther the communication distance. However, the transmission power can not be too large, the transmission power is too large, not only consumes power, affects the life of the power amplifier components, but also has strong interference, affects the call effect of others, and will produce radiation pollution. The radio regulatory bodies of various countries have clear regulations on the transmission power of communication equipment. The higher the receiver sensitivity of the communication machine, the longer the communication distance.
Window walkie-talkie basicThe parameters involve many aspects. The key parameters are listed in detail below for reference. First of all, the working voltage of the window intercom is DC12V, which is the voltage requirement for its normal operation. Secondly, the output power is 3W 3W, indicating the transmission power of the walkie-talkie, which belongs to the output power within the standard range for daily communication use.
1, the cause of harmonics: In an ideal clean power supply system, the current and voltage are sine waves. Contains only linear components (e.g., resistors)In a simple circuit, the current flowing is proportional to the applied voltage, and the current flowing is a sine wave. Using Fourier analysis, the non-sinusoidal signal can be decomposed into its basic parts and its multiples. In power system, the fundamental cause of harmonic generation is due to nonlinear load.
2, harmonics in simple terms means: in complex periodic oscillations, including fundamental and harmonic waves, the frequency corresponding to this period is called the basic frequency. Sine wave components whose frequency is equal to an integral multiple of the fundamental frequency are called harmonics. The fundamental cause of harmonic generation is due to nonlinear load. When the current flows through the loadWhen the voltage is not linearly related to the added voltage, a non-sinusoidal current is formed, resulting in harmonics.
3, the principle of harmonic current can be understood from the following aspects: harmonic generation In the power system, nonlinear load is the main cause of harmonic generation. When the current in the power network passes through the nonlinear load, the current waveform will be distorted, resulting in harmonics. After these harmonic currents enter the power grid, they will interact with the voltage in the power grid to further produce harmonic voltage.
4, the main reasons for harmonic generation are, because the sinusoidal voltage is pressurized on the non-linear load, the fundamental current is distortedGenerating harmonics. The main nonlinear loads are UPS, switching power supply, rectifier, inverter, inverter and so on. Overtones are harmonics in physics, but the definition of frequency is slightly different, audio with 2 times the fundamental frequency is called a primary overtone, audio with 3 times the fundamental frequency is called a secondary overtone, and so on.