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).
Q. What is meant by regulation? The output of most power supplies should be a constant voltage. Unfortunately, this is difficult to achieve. There are two factors that can caus
excitation in an ac generator
Explain Node-voltage and mesh-current analyses? The node-voltage and mesh-current methods, which complement each other, are well-ordered systematic methods of analysis for solv
The block diagram for a 3-bit ripple counter is shown in Figure (a). Obtain a state table for the number of pulses N = 0 to 8, and draw a state diagram to explain its operation.
Internalization of KPI Process It is the responsibility of management to ensure in which the focus of all the participants in performance management and KPI exercise is there
Explain RS422A standard. RS422A: 1. Date Rate: 10 Mbits per second 2. Driving capability up to 4000ft and 10 receivers 3. This is Differential standard that is- a
all about ans in this topic
Operation of Zener Diode The Zener diode's operation depends upon the heavy doping of its p-n junction permitting electrons to tunnel from the valence band of the p-type mater
Voltage Quality Standards - KPI The term voltage quality (or power quality) is an umbrella concept for a variety of disturbances within a power system. The quality of delivere
Q. Explain Television signal transmission? Television signals in television signal transmission are the electric signals generated by converting visual images through raster (T
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