电容式传声器是声学测量中比较理想的传声器，具有动态范围大、频率响应平直、灵敏度高和在一般测量环境中稳定性好等优点，因而应用广泛。由于电容式传感器输出阻抗很高，因此需要通过前置放大器进行阻抗变换，前置放大器装在声级计内部靠近安装电容式传感器的部位。放大器和衰减器?目前流行的许多国产与进口的在放大电路中都采用两级放大器，即输入放大器和输出放大器，其作用是将微弱的电信号放大。输入衰减器和输出衰减器是用来改变输入信号的衰减量和输出信号的衰减量的，以便使表头指针指在适当的位置，其每一挡的衰减量为1分贝。
PV063R1K1T1NFR1
PV063R1K1T1NFHS
PV063R1K1T1NMM1
PV063R1K1T1NMRC
PV063R1K1T1NFWS
PV063R1K1T1NFRC
PV063R1K1T1NFF1
PV080L1K1T1NFFC
PV080R1K1B1NSLB
PV080L1K1T1NFHS
PV080R1L1T1MULC
PV080R1K1A1NFWS
PV080R1K1T1NFRL
PV080R1K1T1NGLA
PV080R1K1T1NMMC
PV080R1L8L3NULC
PV080R1L8T1NULC
PV092R1K8T1N001
PV092R1K1T1NFRZ
PV092R1K1T1NMM1
PV092R1K1T1NMRK
PV092R1K4T1NFHS
PV092R1K1T1NKLC
PV092R1K1T1VMMC
PV092R1L1T1WTCC
PV092R1K1T1NF
PV092R1D1T1NMMC
PV092R1K1T1NGLC
PV092R1K1T1NMF1
PV092R1K1T1WFR1
PV092R1K1T1NULZ
PV092R1K1T1NHLC
PV092R1K1T1NFFC
PV092R1K1A1NFWS
PV092R1K1T1NFHS
PV092R1K1T1NFF1
PV092R1K1T1NFWS
PV092R9K1T1NMMC
PV092R1K1T1NFR1
PV092R9K1T1NFWS
PV092R1K1T1N001
PV092R1K1T1EMMC
PV092R1K1S1NFWS
PV092R1K4T1NMR1
PV092R1L1L3WTCC
PV092R1K1T1NUPM
PV092R1K8T1NMMC
PV092R1K1T1VFDS
PV092R1K1T1NMRC
PV092R1K1T1WMM1
PV092R1K1T1PFDS
PV092R1K1T1WMRC
PV092R1K1A1NMMC
PV092R1K1T1NMMC
PV092R1K8T1VMMC
PV092R1K1T1NMMK
PV092L1K1T1NFWS
PV092R1K1T1NFDS
PV092R1K1T1NKLA
PV092L1K1T1NMMC
PV092R1K4T1NFR1
PV092R1K1T1NMFC
PV092R1K1T1N100
PV092R1K8T1NFWS
PV092R1K1JHNMMC
PV092R1K4T1NMMC
PV092R1K1A4WFRZ
PV092R1K1AYNMRZ
PV092R1K1T1WFDS
PV092R1K1T1NFRC
PV092R1K1T1NHCC
PV092R1D1T1VMMC
PV092R1K1T1NMRZ
PV092R1K1T1WMR1
PV092R1K1T1WMMC
PV092R1K1T1NMR1
PV092R1L1T1NMMC
PV092R1K1T1NFFP
PV092L1K1T1N001
PV092R1D1T1NGLC
PV092R1K1T1NMLA
PV092R1K4T1NFPD
PV092R1L1T1NFPD
PV092L1K1J1NFR1
PV092R1K1A1NSLA
PV140R1K1T1NFRL
PV140L1K8T1NSLC
PV140R1K1T1NTCB
PV140R1L1A1NF
PV140L9G3B1NTCC
PV140R1K1T1NWLA
PV140R1K1T1NSCA
PV140R1D3T1VFHS
PV140L1G1T1NFFP
PV140L1K1T1NFFC
PV140L1K1T1NFFP
PV140L1K1T1NFWS
PV140L1L1T1NWCC
PV140R1D1T1NFFC
PV140R1F1T1NFHS
PV140R1F1T1NYCC
PV140R1F3T1NFFC
PV140R1F3T1NFRP
PV140R1G1T1VFFC
PV140R1K1A1NSCC
PV140R1K1B1NFWS
PV140R1K1B1NUPG
PV140R1K1T1NFDS
PV140R1K1T1NFFC
PV140R1K1T1NFFD
PV140R1K1T1NFFP
PV140R1K1T1NFF1
PV140R1K1T1NFHS
PV140R1K1T1NF
PV140R1K1T1NFRC
PV140R1K1T1NFRD
PV140R1L1T1NUPG
PV140R1L1T1NWCC
PV140R1L4T1NUPG
PV140R1K1T1NMMC
PV140R1K1T1NMRK
PV140R1K1T1NMRZ
PV140R1K1T1NULC
PV140R1K1T1NWCC
PV140R1K1T1NWLC
PV140R1K1T1WMMC
PV140R1L1T1NMMC
PV140R9K1T1NUPZ
PV140R9L1LKNWCC
PV140R9K1A1NSLCK0173
PV140R9K1T1NFDSK0186
PV140R9K1T1NFFCK0011
PV140R9K1T1NFHSK0017
PV140R9K1T1NFRCK0107
PV140R9K1T1NFWSK0032
PV140R9K1T1NFWSK0155
PV140R9K1T1NKCCK0175
PV140R9K1T1NMLCK0081
PV140R9K1T1NSLCK0003
PV140R9K1T1WSCCK0072
PV140R9K4T1NFFPK0088
PV140R9K4T1NZCBK0154
PV140R9K4T1WFRPX5918
PV140L9G1T1NFFPK0083
关于开关电源EMI（Electro-MagneticInterference）的研究，有些从EMI产生的机理出发，有些从EMI产生的影响出发，都提出了许多实用有价值的方案。这里分析与比较了几种有效的方案，并为开关电源EMI的措施提出新的参考建议。开关电源电磁干扰的产生机理开关电源产生的干扰，按噪声干扰源种类来分，可分为尖峰干扰和谐波干扰两种;若按耦合通路来分，可分为传导干扰和辐射干扰两种。现在按噪声干扰源来分别说明：二极管的反向恢复时间引起的干扰高频整流回路中的整流二极管正向导通时有较大的正向电流流过，在其受反偏电压而转向截止时，由于PN结中有较多的载流子积累，因而在载流子消失之前的一段时间里，电流会反向流动，致使载流子消失的反向恢复电流急剧减少而发生很大的电流变化。
