D-6 Industrial Power Electronics Flashcards
What is a Rectifier (converter)
Device that changes A.C. to Pulsing DC.
Forward Bias
Speaker allows current thru
Reverse Bias
Speaker doesnt allow , polaritys wrong
What does the diode do ?
Blocks the second phase of AC
Why are electrolytic capacitors used as filters?
High Capacitance Rating (microfarads)
What is the main dis advantage of using only a capacitor for filtering?
Poor Voltage Regulation
What is a pi filter?
A Filter that contains 2 capacitors and 1 inductor to remove the ripple effect to a higher degree
Red terminal is ?
Positive
Black terminal is?
Negative
The Bended part of the capacitor has a ______ polarity
Negative
Minimum DC working voltage must be greater then …
The AC peak input
minimum PIV rating for the diode ?
2 x Emax voltage =340 v dc
Inductance Filters are also called?
Choke Filters, L Filter
DC working voltage =
AC 12OV / .707 = 170v DC
E rms =
E max x .707
Full wave rectifier has a value of :
.637
Half wave rectifier has a value of :
.318
Power of a half wave rectifier :
P = Emax x Imax / 4
The yellow terminal on a bridge rectifier is the
AC input terminal and there should be two.
The three leads of a transistor are
Base
Collector
Emitter
An ohmmeter testing between the Base and Emitter would find a ____ value of resistance
Low resistance
An ohmmeter testing between the Collector and Emitter would find a ____ value of resistance
High resistance
To find the voltage and current ratings of a transistor where would you look?
Spec manual or data book
Two types of transistors are available: ____ is used in low power applications and _____ for higher current rated transistors
Signal for low power
Power for higher current ratings
The ratio of Ic to Ib is called the ___ of a transistor
Beta
If Vce=Vcc then the transistor is
Cut off
For all transistor circuits, ____ is the sum of Ib plus____.
Ie = Ib+ Ic
If Vrc is very nearly equal to Vcc, then the transistor is said to be _____
Saturated
If Vrc is zero, then ____ is equal to Vcc.
Vce
Design considerations when building a Pi filter
Ripple frequency Load voltage Load current Peak current limits Allowable voltage regulation
T or F
Form factors are used to determine the average voltage when the rms voltage is known in a full wave or half wave rectifier.
True
Important junction diode ratings are?
PIV -the amount of voltage it can take with out damage.
Forward dropping voltage-
Power rating- how much wattage can be taken before damage occurs
Undoped semi conductors have__ electrons in their valence orbit
4
