A series resonant capacitor is simply the result of surface mount devices and pin leads. For a typical plug-in capacitor, its average equivalent series inductance is 2.5nH/2.54mm. The average equivalent series inductance of surface mounted capacitors is 1nH. Based on the above, it is important to consider the equivalent series inductance of capacitors when using decoupling capacitors. Surface mounted capacitors have better performance than plug-in capacitors at high frequencies because their equivalent series inductance is very low.
Blocking network 2 is used to block f1=747KHZ, taking C2=1250pF, then:
What is resonant frequency
A power of 1mW is applied on a 600 Ω load, and the voltage value on the load is at zero level. At this time, the AC voltage on the load is 0.775V.
Definition of resonant frequency
The impedance of an ideal capacitor decreases with increasing frequency, while the impedance of an actual capacitor exhibits capacitive characteristics at lower frequencies, where the impedance decreases with increasing frequency and resonates at a certain point where the impedance of the capacitor is equal to the equivalent series resistance ESR. Above the resonance point, due to the effect of ESL, the capacitance impedance increases with the increase of frequency, thus weakening or even disappearing the bypass effect on high-frequency noise.
LC filter cut-off frequency calculation
A certain medium wave transmitter has an output power of 10KW in carrier state, and the three-phase power supply phase voltage is Ua=218V, Ub=220V, Uc=225V; The measured currents for each phase are Ia=18A, Ib=17A, and Ic=17A, respectively; Calculate the input power of the transmitter and calculate the actual overall efficiency.
The R4 in low-power TTL gate circuits is relatively large, resulting in smaller peak currents. When the input voltage changes from low level to high level, the output level of the NAND gate changes from high to low, and T3 and T4 may also conduct simultaneously. But when T3 starts to conduct, T4 is in an amplified state, and the collector emitter voltage between the two tubes is high, so the peak current generated is small, and the impact on the power supply current is relatively small.
Due to the presence of a magnetic field near the cable, it is easy for the magnetic field to leak from the hole (regardless of the frequency of the magnetic field). Therefore, when the cable is very close to the gap and hole, magnetic field leakage will occur, reducing the overall shielding effectiveness.
Rotate the direction of the screen slightly to form a 15-20 degree angle between the latitude lines and the scanning lines of the display tube. Attention to the formula for measuring sound velocity: The estimated parasitic inductance of the plug-in in the table is L=3.75nH; 0805 package parasitic inductance estimation L=1nH.
What is the speed of sound
Corresponding network information security regulations should be formulated based on the actual situation of the unit's equipment operation monitoring system, power and environmental monitoring system, and broadcasting related information systems, clarifying the information security requirements for daily operation and maintenance;
Although capacitor resonance is not desirable from the perspective of filtering high-frequency noise, capacitor resonance is not always harmful. When the frequency of the noise to be filtered out is determined, the capacitance of the capacitor can be adjusted to make the resonance point just fall on the disturbance frequency.
This article mainly introduces the working principle, selection, capacitance calculation, and specific use of decoupling capacitors.
Therefore, the low value approximation allows us to derive a simplified analytical expression for the design oriented transition frequency.
The bypass capacitor used in DC filters is a DC capacitor, which may overheat and be damaged under AC conditions. If the withstand voltage of the DC capacitor is low, it may also be broken down and damaged. Even if these two situations do not occur, the capacity of the common mode bypass capacitor in a typical DC filter is relatively large, which can result in excessive leakage current when used in AC situations, violating safety standards.
Therefore, for situations where significant damping is caused by both and, a high-value approximation can be used to estimate the composite factor based on and:
The transmission frequency of a certain medium wave transmitter is 1251KHZ, and its wavelength is 239.8 meters.
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