• Study Resource
  • Explore
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
The Wireless Feeding Flexible Printed Circuit Which is Available for
The Wireless Feeding Flexible Printed Circuit Which is Available for

... In the antenna section, the antenna circuits of the transmitter and receiver modules have been optimized to reduce power transmission losses. Figure 3 shows the output characteristics of the receiver antenna circuit with the newly developed transmitter and receiver being opposed to each other. The i ...
Digital Multi-meter and Oscilloscope
Digital Multi-meter and Oscilloscope

... trace is swept in the vertical direction by the voltage input to the oscilloscope. The combination of these two sweeps allows observation and analysis of time varying voltages. Since we are not using a “real oscilloscope”, but adapting the computer to act as an oscilloscope the function is not quite ...
Double Sheet Metal Sensor BDK Duo Flex
Double Sheet Metal Sensor BDK Duo Flex

ME 3484
ME 3484

voltage regulators 1
voltage regulators 1

179 The priority on usage of any amateur radio repeater is
179 The priority on usage of any amateur radio repeater is

CLF W-Bridge - CLF
CLF W-Bridge - CLF

... Compatible with all DMX512 compliant equipment FHSS (Frequency-Hopping Spread Spectrum) technology POWERCON-compatible power input Wireless solution Sweden® powered ...
555 Timer As Mono Stable Multi Vibrator
555 Timer As Mono Stable Multi Vibrator

PRACTISE AND REVISION KIT
PRACTISE AND REVISION KIT

... A spectrum analyser displays signals in the time domain; an oscilloscope displays signals in the frequency domain A spectrum analyzer displays signals in the frequency domain; an oscilloscope displays signals in the time domain A spectrum analyzer displays radio frequencies; an oscilloscope displays ...
Accurate Measurement of the Air-Core Inductance of Iron
Accurate Measurement of the Air-Core Inductance of Iron

... inrush currents, ferroresonance, and geomagnetic-induced currents [1]). However, it is not easy to measure in the field or laboratory because a very large ac power source (more than 10 times larger than the transformer rating) is needed. This is so because high voltage is needed to push the core int ...
Producing diamond anvil cell gaskets for ultrahigh
Producing diamond anvil cell gaskets for ultrahigh

... flex markedly during drilling, severely complicating the centering procedure. Laser drilling is another method for preparing holes but, of course, is dependent on the availability of a high-power laser with appropriate focusing optics. A typical high-power Nd:YAG or CO, laser used in these applicati ...
Amateur Radio Technician Class Element 2 Course Presentation
Amateur Radio Technician Class Element 2 Course Presentation

ary Friend PrEng Sales Director EXTECH SAFETY SYSTEMS PTY LTD
ary Friend PrEng Sales Director EXTECH SAFETY SYSTEMS PTY LTD

... ignition (spark or heat) need to be present. Intrinsic Safety works on the principle of removing the source of ignition. This can be achieved by using a Zener Barrier or Galvanic Isolator. A zener barrier is a simple device where the voltage is limited by a zener diode and the current by a resistor. ...
Soft-switching of the full-bridge converter switches must
Soft-switching of the full-bridge converter switches must

Experiment FT2
Experiment FT2

... production of mutually induced e.m.f in the secondary coil. A mutual inductance M may be defined to quantify the ability of one coil to produce an e.m.f in a nearby coil by induction when the current in the first coil changes. This action is reciprocal, i.e., the second coil can also induce an e.m.f ...
Current Transducer HAT 200..1500
Current Transducer HAT 200..1500

... Caution! Risk of electrical shock ...
373KB - NZQA
373KB - NZQA

... ( V = and C is constant) C As more and more charges accumulate on the plates, it will be harder for electrons to accumulate on the plates due to repulsive forces. Electrons will then start flowing on to the capacitor more slowly (current decreases) and so voltage rises more slowly (less difference i ...
Power systems (A. Kwasinski)
Power systems (A. Kwasinski)

DYNAMIC VOLTAGE FREQUENCY SCALING (DVFS) FOR
DYNAMIC VOLTAGE FREQUENCY SCALING (DVFS) FOR

... special instruction, and then it is woken up by certain interrupts, this cause producing idle intervals between the tasks [11]. Therefore, work load of the processor usually consists of sequence of tasks and idles between tasks. By scaling down the voltage and frequency each task is extended into th ...
Before Hydraulic AGC Cylinders became a standard fixture in flat
Before Hydraulic AGC Cylinders became a standard fixture in flat

... rising to un safe value. To ensure this rolls gap is set to a given value in position mode and null setting screw on the servo valve is adjusted such that drive side and operator side servo valves need an equal positive current (which would have reduced roll gap if not in position mode). This means ...
phys1444-spring12
phys1444-spring12

Electrical Current
Electrical Current

USN 10EE15/25  B. E. Degree First Semester End Examination (SEE), December 2010
USN 10EE15/25 B. E. Degree First Semester End Examination (SEE), December 2010

... (C) Braking torque is equal to operating torque (D) Operating torque is constant xix) Short pitched windings in alternators ...
PDF
PDF

Transient analysis of resistor-capacitor system
Transient analysis of resistor-capacitor system

... Resistors and capacitors are fundamental elements of any circuit. Even the behavior of semiconductor devices in your computer can be modeled employing these basis elements (along with some others). A transistor is comprised of junctions of different kinds of materials, giving rise to interesting ele ...
< 1 ... 272 273 274 275 276 277 278 279 280 ... 367 >

Spark-gap transmitter



A spark-gap transmitter is a device that generates radio frequency electromagnetic waves using a spark gap.Spark gap transmitters were the first devices to demonstrate practical radio transmission, and were the standard technology for the first three decades of radio (1887–1916). Later, more efficient transmitters were developed based on rotary machines like the high-speed Alexanderson alternators and the static Poulsen Arc generators.Most operators, however, still preferred spark transmitters because of their uncomplicated design and because the carrier stopped when the telegraph key was released, which let the operator ""listen through"" for a reply. With other types of transmitter, the carrier could not be controlled so easily, and they required elaborate measures to modulate the carrier and to prevent transmitter leakage from de-sensitizing the receiver. After WWI, greatly improved transmitters based on vacuum tubes became available, which overcame these problems, and by the late 1920s the only spark transmitters still in regular operation were ""legacy"" installations on naval vessels. Even when vacuum tube based transmitters had been installed, many vessels retained their crude but reliable spark transmitters as an emergency backup. However, by 1940, the technology was no longer used for communication. Use of the spark-gap transmitter led to many radio operators being nicknamed ""Sparks"" long after they ceased using spark transmitters. Even today, the German verb funken, literally, ""to spark,"" also means ""to send a radio message or signal.""
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report