Disclosed are a full-wave drive circuit for an ultrasonic atomizing sheet and an ultrasonic electronic cigarette. In an embodiment, the ultrasonic atomizing sheet full-wave drive circuit comprises a power supply module, a microprocessor, a high-frequency square wave generation circuit, an NMOS transistor and a resonance circuit configured to convert, on the basis of the NMOS transistor, a voltage signal outputted by the high-frequency square wave generation circuit into a full-wave oscillation signal, so as to drive the ultrasonic atomizing sheet to perform full-wave oscillation. A disclosed embodiment has low requirements for a boost module, low loss of the boost module, high power conversion efficiency, small volume, low loss of NMOS transistor and low cost, is easy for debugging, and has high reliability and good atomization effect.

An electromagnetic encoding switch and a method for calculating rotation information of a runner. The electromagnetic encoding switch (10) comprises: a runner assembly (11), wherein the runner assembly (11) comprises an LC resonant circuit (111), the LC resonant circuit (111) comprising an inductor L and a capacitor C connected to the inductor L, the inductor L having a magnetic core, and the inductor L being used for receiving and transmitting electromagnetic waves; a runner (112), the LC resonant circuit (111) being disposed on the runner (112); a transceiver unit (12), the transceiver unit (12) comprising an antenna (121) disposed below the runner (112) and used for transmitting electromagnetic waves at a preset frequency in a transmitting period, so that the LC resonant circuit (111) receives energy in the transmitting period; and an antenna selection switch (122) connected to the antenna (121). The electromagnetic encoding switch (10) has no mechanical noise and is low-cost.

A power conversion device includes: main circuits each having a plurality of power modules that are parallelly connected to each other; and driving circuits for driving the main circuits. The driving circuits are each provided with: at least one driver for generating control signals to be inputted to the respective module control terminals of the plurality of power modules; and a filter that is connected between the at least one driver and the module control terminals, the filter having, per each module pair formed of two power modules, an impedance characteristic with a peak shape showing an increased impedance in a predetermined specific frequency range. The filter has a coupling element per each module pair, the coupling element being connected between two module control terminals and including a capacitor.

An apparatus includes a switch arrangement comprising a switching element and a control device that is configured to switch the switching element on the basis of a turn-off current that is determined by the relationship that

[00001]$I_{T0,n}=\frac{V_{\mathrm{DC}}\sqrt{\frac{{\left(C_{\mathrm{eff}1}+C_{\mathrm{eff}2}\right)}^3}{C_{\mathrm{eff}1}{C}_{\mathrm{eff}2}{L}_p}}}{n}$

wherein I.sub.T0,n describes the turn-off current to be turned off by the switching element, V.sub.DC describes an intermediate circuit voltage of the commutation circuit, C.sub.eff1 describes an effective capacitance of the commutation resonant circuit associated with the switching element, C.sub.eff2 describes an effective capacitance of the commutation resonant circuit associated with the free-running element, L.sub.p describes an effective electrical inductance of the commutation resonant circuit, and n describes a natural number; wherein at least one of the conditions is satisfied:

[00002]$\begin{array}{cc}n=2i+1,i;& 1)\end{array}$

A semiconductor device includes first semiconductor elements, a control terminal, a first conductive member, and first circuit components. The first semiconductor elements are connected in parallel, and a switching operation of each first semiconductor element is controlled according to a first drive signal inputted to a third electrode of each first semiconductor element. The first conductive member is electrically connected to the control terminal to which the first drive signal is inputted, and is electrically interposed between the third electrodes. The first conductive member includes connecting members and a portion of a signal wiring section. Each of the first circuit components increases an impedance in a first frequency band. The first frequency band includes a resonance frequency of a resonance circuit that is formed by including a parasitic inductance of the first conductive member. The third electrodes of the first semiconductor elements are electrically connected to each other via at least one of the first circuit components.