What are the precautions and advantages of using a variable frequency series resonance test device? Wuhan UHV specializes in producing series resonant devices, with a wide range of product selection and professional electrical testing. When looking for series resonant devices, choose Wuhan UHV.
The first meaning of Q value - energy storage and energy consumption
From the energy relationship during the resonance of an RLC series circuit, it can be seen that the ratio of w to w reflects the efficiency of energy storage in a resonant circuit. The quality factor of a resonant circuit (Q value is equal to 27c times the ratio of energy stored in the resonant circuit to energy consumed in each cycle. The larger the Q value, the less energy consumption is required compared to the stored energy, that is, the higher the energy storage efficiency of a resonant circuit, the less energy consumption is required to store the same energy; The smaller passband stores more energy. The energy supplied by the power supply circuit is entirely consumed by the resistor R, while the energy storage and discharge process of the dynamic component is completely completed between the capacitor and the inductor, that is, the energy storage component does not exchange energy with the power supply. This is the first and most common meaning of the Q value of the resonant circuit. This meaning applies to all resonant systems (mechanical, electromagnetic, optical, etc.). The Q value in microwave resonant cavities and optical resonant cavities refers to this meaning. There is a so-called "Q-switching" technology in lasers, which uses the concept of "Q value" in this sense
The Second Meaning of Q Value - Voltage Allocation
In resonance, generally Q>l, U-U, U-U-QU>U, that is, the voltage of the inductor and capacitor is equal, and it is Q times (tens to hundreds of times) the voltage of the signal source. Therefore, the series resonant circuit is also known as the voltage resonant circuit. This characteristic of the series resonant circuit provides us with a method to measure the Q value of the reactive element. The most commonly used instrument for measuring Q value, the Q meter, is made based on the above principle. For example, when the Q value of a resonant circuit is 100, if a voltage of 6V is applied to both ends of the circuit, the voltage on the capacitor or inductor during resonance will reach 600V. If this is not noticed in practical operation, it will be very dangerous. In order to avoid breakdown of circuit equipment (L, C, etc.), resonance should be avoided as much as possible; In electronic circuits, this method is commonly used to obtain high voltage
The third meaning of Q value - frequency selectivity
For an RLC series circuit, when a sine AC signal source with a constant voltage amplitude and continuously adjustable frequency is connected, the current, voltage, impedance, phase difference, etc. in the circuit all change with frequency. This relationship with frequency is called frequency characteristic. The curve indicating the relationship between current, voltage and frequency is called resonance curve. Figure 5 shows the circuit parameter Z, which changes with the frequency of the signal source. The curve of the effective value of the current in the series resonant circuit changing with the power frequency is called the current amplitude frequency curve or current resonance curve of the series resonant circuit. From Figure 5 (b), it can be seen that when cu is one. When the rT current in the circuit reaches its maximum value, i.e. - J. I. When CO deviates from 09. Due to the increase in reactance x, the impedance z of the circuit increases and the current decreases; deviate. The farther away, the greater the decrease in current
The current resonance curve indicates that due to the resonance characteristics of the series resonant circuit, it generates a large current near the frequency of CO and a small current far away from cU. This suggests that the series resonant circuit has different responses to signals of different frequencies, indicating that it has the ability to select the desired frequency signal. Therefore, the series resonant circuit can be used as a frequency selection circuit.