Switch dynatron, quicken the analysis of capacitance!

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Introduction: As a result of charge memory effect, there is one to receive capacitance between transistor BE, make RC circuit with Rb, time constant is bigger affected transistor guide connect and up to speed (namely switch speed) switch dynatron, quicken the analysis of capacitance! 1, as a result of charge memory effect, there is one to receive capacitance between transistor BE, make RC circuit with Rb, time constant is bigger affected transistor guide connect and up to speed (namely switch speed) . 2, accelerate capacitance effect. (when 1) controls pulse low n, when circuit reachs stable state, transistor up to, two upright voltage are capacitance 0. (2) when control pulse tall n comes, as a result of capacitance voltage cannot choppy, capacitance needs to continue to maintain 0, such, mutation of voltage of transistor base B arrives tall n, make transistor guides quickly; Capacitance is charged pulse n voltage; Enter stable state, capacitance voltage is pulse n voltage. (3) after this, when control pulse low n comes, as a result of capacitance voltage cannot choppy, need to continue to maintain pulse n voltage, accordingly, base voltage from 0 (fall actually for Be pressing) jump the pulse n voltage that becomes negative, canal of Shi Dejing body turns quickly from saturated condition up to condition; After this, capacitance passes R discharge, when reaching stable state, two upright voltage are 0. (4) next, repeat above process. 1. Typical acceleration graph of capacitance circuit T491D475M050AT is shown 2 times is pulse amplifier (the amplifier of signal of pulse of a kind of enlarge) medium acceleration capacitance circuit. The VT1 in circuit is dynatron, it is pulse enlarge canal, cl paralell connection is on Rl, cl is to quicken capacitance. The action of Cl is to accelerate VT1 to guide the changeover speed that connect and ends, call so quicken capacitance. 2. The dynatron VT1 job in circuit of analysis of circuit job principle falls in switch condition (be equivalent to a switch) , ui is the input signal tension that increases dynatron VT1 base, it is signal of a rectangular pulse. When U is tall n, dynatron VT1 saturation guides; When Ui is low n, dynatron VT1 ends. The equivalent circuit that quickens capacitance Cl and dynatron VT1 to input resistor Ri to if graph 3(a) place is shown,be formed. (1) guides quickly through Cheng. When the input signal voltage Ui jumps from OV when changing to be made the same score to tall report, as a result of capacitance Cl the voltage of two end cannot choppy, the tension that increases VT1 base is pulse of a fastigium, its voltage amplitude is the biggest, if pursue,3 (b) place is shown. Pulse of this one fastigium increases VT1 base, make VT1 base electric current increases quickly from OA very big, such VT1 enter saturated state quickly from off-state, the saturation that quickened VT1 guides, shortened namely VT1 saturation guides a time (dynatron from end the time that enters saturated place need) . (2) is maintained guide through Cheng. After T0, to Cl charge to end very quickly, the electric pressure ratio that inputs signal voltage Ui to increase VT1 base at this moment is lesser, maintain the saturated on-state of VT1. (3) ends quickly process; When the input signal voltage U jumps suddenly from tall n change when OV, be like the Tl hour that graph 3(b) place notifies, it is Zun Zheng as a result of the fills formerly voltage polarity on Cl right negative, the tension that increases VT1 base is negative fastigium pulse. Because add the voltage of VT1 base to be,lose, accelerated VT1 from base the process that the area takes out charge, VT1 changes off-state from saturation with rapidder rate, shortened namely VT1 to end the time of changeover. Because receive capacitance Cl, VT1 enters saturated state with rapidder rate, also be likewise enter off-state with rapidder rate, visible capacitance Cl has the effect that accelerates transition of VT1 job state, call Cl so quicken capacitance. This kind quickens capacitance circuit to basically appear in electronic switch circuit (the circuit that serves as switch with dynatron) or in pulse amplifier circuit, frequency amplifier need not this kind of circuit. Origin: Network of electronic component technology CNC Milling CNC Machining