NAVEDTRA 14179A, NAVY ELECTRICITY AND ELECTRONICS TRAINING SERIES, MODULE 7-SOLID-STATE DEVICES AND POWER SUPPLIES Flashcards
Which year was the first transistor discovered?
1948
What are semiconductor devices called that have-three or more elements?
Transistors
In which ways are transistors classified?
NPN or PNP
What were the very first transistors known as?
Point-contact
Which type of transistor generates less noise, handles more power, provides higher current and voltage gains, and can be mass-produced more cheaply than the point-contact transistor?
Junction
What is the process called of increasing the strength of a signal?
Amplification
Which device provides amplification without appreciably altering the original signal?
Amplifier
What is returning a part of the output back to its input known as?
Degeneration
How many classes of amplifier operations are there?
Four
Which class of amplifies are biased so that variations in input signal polarities occur within the limits of cutoff and saturation?
Class A
What occurs when the base becomes so negative with respect to the emitter that changes in the signal are not reflected in collector-current flow?
Saturation
Amplifiers designed for what class of operation are biased so that collector current is zero (cutoff) for a portion of one alternation of the input signal?
AB
Amplifiers biased so that collector current is cut off during one-half of the input signal are classified as what class?
B
What is the faithful reproduction of a signal called?
Fidelity
Which amplifier property refers to the ratio of output-signal power compared to the total input power?
Efficiency
Which amplifier class has the highest efficiency of the four classes of amplifier operations?
Class C
How many basic configurations may a transistor be connected in?
Three
What is the most frequently used arrangement in practical amplifier circuits?
Common-Emitter configuration (CE)
Which term is used to describe the amplification capabilities of the amplifier?
Gain
What is the relationship of collector current (output current) to base current (input current)?
Beta
What is the relationship of collector current (output current) to emitter current (input current)?
Alpha
Which transistor properties are the direct voltage and current values that if exceeded in operation may result in transistor failure?
Absolute Maximum Ratings
What is one of the greatest dangers to the transistor which will cause excessive current flow and eventual destruction of the transistor?
Heat
Gain, leakage, breakdown, along with what else are the four basic tests required for transistors in practical troubleshooting?
Switching time
What is a flat insulating surface upon which printed wiring and miniaturized components are connected in a predetermined design, and attached to a common base?
Printed circuit board
Printed circuit boards are stacked and connected together to form a module using what technique?
Modular circuitry
Which device integrates (combines) both active components (transistors, diodes, etc.) and passive components (resistors, capacitors, etc.) of a complete electronic circuit in a single chip (a tiny slice or wafer of semiconductor crystal or insulator)?
Integrated Circuit
What are the two general classifications of integrated circuits?
Hybrid and Monolithic
In which type of integrated circuits do all elements (resistors, transistors, etc.) associated with the circuit fabricated inseparably within a continuous piece of material (called the SUBSTRATE) which is usually silicon?
Monolithic
What are two terminal semiconductors of various types that are used in seemingly endless applications?
Diodes
What is a PN junction that is designed to operate in the reverse-bias breakdown region?
Zener diode
Which year was the zener effect first produced by Dr. Carl Zener?
1934
Which process according to Dr. Zener’s theory does electrical breakdown in solid dielectrics occur by?
Quantum-Mechanical tunneling
What is a band in which the energy level of the electrons is high enough that the electrons will move easily under the influence of an external field?
Conduction
What are solid materials called that have many electrons in the conduction band?
Conductors
What is a band in which the energy level is the same as the valence electrons of the atoms?
Valence
What is a material in which the forbidden gap is so narrow that it can be considered nonexistent?
Conductor
What is a solid that contains a forbidden gap?
Semiconductor
What are materials in which the forbidden gap is so large that practically no electrons can be given enough energy to cross the gap?
Insulators
What is the most widespread use of Zener diodes?
Voltage regulators
Which year did Leo Esaki discover that if a semiconductor junction diode is heavily doped with impurities then it will have a region of negative resistance?
1958
In the tunnel diode, the semiconductor materials used in forming a junction are doped to the extent of how many impurity atoms for ten-million semiconductor atoms?
1000
What is the most important and most widely used characteristic of the tunnel diode?
Negative resistance region
Which type of diode behaves like a variable capacitor, with the PN junction functioning like the dielectric and plates of a common capacitor?
Varactor
How high can the ratio of varactor capacitance to reverse-bias voltage change be?
10 to 1
What can be used to check a varactor diode in a circuit?
Ohmmeter
What functions as a switch that can turn on or off small or large amounts of power?
SCR
Some SCRs can be switched how many times a second?
25,000
The input resistance of the SCR is relatively low (approximately how many ohms) and requires current for triggering?
100
Which type of devices either produce light or use light in their operation?
Optoelectronic
LED operating voltage is small, about 1.6 volts forward bias and generally about how many milliamperes?
10
What is the life expectancy of the LED?
100,000+ hours
What is a light-controlled variable resistor?
Photodiode
What is typical light-to-dark resistance ratio for a photocell?
1:1000
Which type of device converts light energy into electrical energy?
Photovoltaic cell
What is often used when it is necessary to block the voltage between one electronic circuit and another, and transfer the signal at the same time?
Amplifier coupling capacitor
Transistors are semiconductor devices with how many or more terminals?
Three
How many distinct types of UJTs are presently in use?
40+
What uses voltage to control electrostatic field within the transistor?
FET
The MOSFET has a higher input impedance than the JFET (how many megohms)?
10 to 100 million
The MOSFET is normally constructed so that it operates in one of what two basic modes?
Depletion or Enhancement
Most power supplies are made up of the following four basic sections: transformer, rectifier, filter, and what else?
Regulator
What steps up or steps down the input line voltage and isolates the power supply from the power line?
Transformer
What converts the alternating current input signal to a pulsating direct current?
Rectifier
What maintains the output of the power supply at a constant level in spite of large changes in load current or input line voltages?
Regulator
What provides two equal voltages to the conventional full-wave rectifier?
Center-tapped transformer
What is the conversion of an alternating current to a pulsating direct current?
Rectification
What is current called that flows in pulses in the same direction?
Pulsating DC
Which terms are AC voltages normally specified in?
RMS values
Which type of device has two or more diodes arranged so that load current flows in the same direction during each half cycle of the ac supply?
Full-wave rectifier
How many basic types of filter circuits are there?
Four
What is defined as the time it takes a capacitor to charge to 63.2 percent of the applied voltage or to discharge to 36.8 percent of its total charge?
One time constant
What is the most basic type of power supply filter?
Capacitor filter
Which type of filter is primarily used in power supplies where voltage regulation is important and where the output current is relatively high and subject to varying load conditions?
LC choke-input
What percent of a half-wave rectifier is the ripple frequency of a full-wave rectifier?
200%
Electrolytic capacitors are available in sizes up to how many microfarads or greater?
10,000
What is one of the most commonly used filters primarily used in radio receivers, small audio amplifier power supplies, and in any type of power supply where the output current is low and the load current is relatively constant?
LC capacitor-input filter
115 volts AC can vary from about 105 volts AC to how many volts AC?
125
What gives an indication of how much the output voltage changes over a range of load resistance values?
Figure of merit
Basic voltage regulators are classified as one of what two ways?
Series or shunt
Which type of diode blocks current until a specified voltage is applied?
Zener diode
Which circuitry provides a constant current output?
Current regulator
What are used primarily to develop high voltages where low current is required?
Voltage multipliers
The DC output of the voltage multiplier ranges from 1000 to how many volts?
30,000
In order for a silicon NPN transistor to conduct, the base must be between how many volts more positive than the emitter?
0.6 to 0.7 volts
What are the two widely used checks in testing electronic equipment?
Signal tracing and Visual
What is a short-circuit protection device that automatically limits the current to a safe value?
Current Limiter
