Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Reverse Recovery Characteristics
At the end of forward conduction in diode reverse current flows for a short time. The device doesn't attain its full blocking capability until the reverse current cease. The reverse current flows in the interval called reverse recovery time. During this time charge carriers stored in the diode at the end of forward conduction are removed. Actually when a power diode has been conduction in the forward direction sufficiently long to establish the steady state there will be a charge due to minority carriers present. Before the device can block in the reverse direction this charge must be extracted.
This extraction takes the from of a transient reverse current and this together with the reverse bias voltage results in additional power dissipation which reduces the rectification efficiency. Reverse recovery time is measured instant the current recovers to 25% of its peak reverse value. low reverse state forward current and low reverse bias voltage increase recovery time. High rate of all of anode current reduces recovery time but increase stored charge. High junction temperature is increase both recovery time and stored charge.
There are two parts of reverse recovery time. One is the time between zero crossing of forward current and peak reverse current. During this time period, charges stored in depletion region is removed. The other part of t measured form the instant of peak reverse current to the instant where 25% of peak reverse current is reached. During this time period charges from the two semiconductor layer are removed.
The shaded area in figure represents the stored charge or reverse recovery charge which must be removed during the reverse recovery time. The ration ½ is known as softness factor. Voltages transient occurs during the time diode recovers is measured by the factor.
b. forward voltage drop vf and forward current if gives the power loss in a diode. The total power loss in given by average value of V f i f during time t2 major power loss occurs in a diode. As shown in figure peak reverse current IFP is given by
I = RP = t1 di/ dt
Where Do/ dt is the rate of rise of reverse current. If the reverse recovery characteristics is assumed as a triangle shape then storage charge Q can be written as .
Q = ( ½) (IRP ) (t rr).
A 10-kHz tone is used to frequency modulate a carrier; the peak deviation is 75 kHz. Use Carson''s rule to estimate the bandwidth.
A burglar alarm system is controlled by a microprocessor system. The system has three independent circuit each consisting of 7 passive infra red sensors. The controller can be prog
Q. Show Maximum Common-Mode Input Voltage of amplifier? This is the maximum voltage that the two inputs can be raised above ground potential before the op amp becomes nonlinear
Q. Write a short note on the frequency response of a R-C coupled amplifier. At low frequencies ( , the reactance of coupling capacitor Cc is quite high and hence very small pa
we work as a group on Automoted guided vehicles project, with 2 vehicles one is leading and the other is guided and following the first one, i was assigned to write an obstacle avo
Q. Show Benefits of digital systems? Ever since most digital systems have only two possible states, there is high degree of accuracy in the transmission of data. With an analog
You are required to design and document the hardware design for Lift Control Unit (LCU) as required by the questions/specification in section 2 above, based on a 68HC12D60 microcon
Revenue Loss Due to Loss of Opportunity to Serve The revenue loss because of "loss of opportunity to serve" is a extremely relevant but less visible aspect of revenue loss. Gu
Define branch prediction logic in Pentium. Branch prediction logic in Pentium: The Pentium microprocessor utilizes branch prediction logic to decrease the time required for a
Q. Illustrate working of Application Layer? As the highest layer in OSI reference model, application layer provides services to users of OSI environment. Layer
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd