NAVEDTRA 14193A, NAVY ELECTRICITY AND ELECTRONICS TRAINING SERIES. MODULE 21- TEST METHODS AND PRACTICES Flashcards
In equipment that uses vacuum tubes, faulty tubes are responsible for more than what percent of all electronic equipment failures?
50
If the average receiving vacuum tube is not overdriven or operated continuously at maximum rating, it can have a life of at least how many hours before the filament opens?
2,000
Klystron tubes that remain inoperative for more than how many months may become gassy?
6
How many hours or more of reduced voltage operation may be required for klystrons that have been inoperative for periods in excess of 6 months?
Eight
When the twt is installed, you can usually measure the collector current and voltage and check the power output for various inputs. Any deviation greater than what percent from normal specifications may be considered to be an indication of a defective tube?
10%
Transistor circuits, other than pulse and power amplifier stages, are usually biased so that the emitter current is from 0.5 milliampere to 3 milliamperes and the collector voltage is from 3 to how many volts?
15
A back-to-forward resistance ratio on the order of what or greater should be obtained for the collector-to-base and emitter-to-base measurements?
100 to 1
Many ohmmeters are designed such that on the R x 1 range, how many milliamperes or more can flow through the electronic part under test?
100
Ohmmeter ranges that require a current of more than what in the test circuit are not to be used for testing transistors?
1 milliampere
What should not be used to furnish power for transistor equipment because they have poor voltage regulation and, possibly, high ripple voltage?
Battery eliminators
What is created whenever two substances (solid or fluid) are rubbed together or separated?
Static electricity
An MOS field-effect transistor (MOSFET) can be damaged by a static voltage potential of as little as how many volts?
35
When moving an ESDS device or assembly, always touch (with your bare skin) the surface on which it rests for at least how long before picking it up?
1 second
Transistors are capable of operating in excess of how many hours at maximum ratings without appreciable degradation?
30,000
What is a three-element, solid-state device in which the forward resistance can be controlled?
SCR
What device is designed to switch from a blocking state to a conducting state or either polarity of applied voltages and with either positive or negative gate triggering?
Triac
What is a solid-state, three-terminal semiconductor that exhibits stable open-circuit, negative-resistance characteristics?
Unijunction Transistor (UJT)
What must never be used in testing MOSFETs?
VTVM
What constitutes an area of microelectronics in which many conventional electronic components are combined into high-density modules?
Integrated Circuits (ICs)
The most frequently used ICs are manufactured with either 14 or how many pins?
16
What are spring-loaded devices that are designed to clip onto a dual-in-line package IC while the IC is mounted in its circuit?
Logic clips
What is designed to detect faulty, in-circuit-DIP ICs by comparing them with ICs that are known to be good (reference ICs)?
Logic comparator
What can immediately identify whether a specific point in the circuit is low, high, open, or pulsing?
Logic probes
Some logic probes have a feature that detects and displays high-speed transient pulses as small as how many nanoseconds wide?
5
What provides various functions that can assist you in maintenance, testing, and troubleshooting of equipment using digital circuitry?
Logic analyzer
Most logic analyzers have crt displays that can monitor up to how many timing signals at the same time?
32