• 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
1 - QSL.net
1 - QSL.net

ppt_ch17
ppt_ch17

Thursday, Dec. 1, 2011
Thursday, Dec. 1, 2011

... – What happens at the instance the switch is thrown to apply emf to the circuit? • The current starts to flow, gradually increasing from 0 • This change is opposed by the induced emf in the inductor  the emf at point B is higher than point C • However there is a voltage drop at the resistance which ...
STT 3000 Series STT250 - Honeywell Process Solutions
STT 3000 Series STT250 - Honeywell Process Solutions

... Calibration of the LRV/URV end points will typically give accuracy improvements of 2 times. Sensor errors can be calibrated out by calibration to the specific sensor either by having it at the LRV/URV temperatures or by simulation of the known values. In addition, all units pass through Environmenta ...
Rennie Maintenance and tune up
Rennie Maintenance and tune up

DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1
DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1

D048012127
D048012127

... of industrial applications and allows significant brazing, andsoldering. Much attention has therefore scaling for larger implementations. been focused uponthe development of inverters capable of supplying high-powerto induction heating loads at frequencies ranging from 10to 200 kHz. A II. INDUCTION ...
High pass filter
High pass filter

... Let‘s construct the gain-frequency characteristic of the RC high-pass filter. Let‘s apply a voltage Vin of a very low frequency to the input of the circuit. If the frequency becomes lower and lower, the input voltage will become a DC voltage. No DC current can pass through the capacitor because ther ...
circuit description - Allegro MicroSystems
circuit description - Allegro MicroSystems

IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)

microwave engineering
microwave engineering

... a) A short circuit may always be placed in one of the arms of a three port junction in such a way that no power can be transferred through the other two arms. b) If the junction is symmetric about of its arms, a short circuit can always be placed in that arm so that no reflections occur in power tra ...
Power System Transients - Chapter 1
Power System Transients - Chapter 1

... The three-phase systems can be solidly grounded at their neutrals, they can be completely isolated from ground, or they can be grounded through a neutral impedance of some kind. The transient voltages caused by switching operations or other disturbances (faults) will often depend upon the neutral po ...
Welding 1-6
Welding 1-6

... The deflection of an electric arc from its normal path because of magnetic forces. Uneven magnetic flux lines can cause an arc to move during a weld. More noticeable in corners, at ends of plates, when the work (ground) lead is connected to only one side of the of a plate, or if the plate has been m ...
Chapter 7
Chapter 7

... • The key to working with this type of situation is: • Start with the initial voltage across the capacitor and the time constant. • With these two items, the voltage as a function of time can be known. • From the voltage, the current can be known by using the resistance and Ohm’s law. • The resistan ...
Inductor Transient Analysis
Inductor Transient Analysis

Wireless Music transmission and reception by IR communication
Wireless Music transmission and reception by IR communication

... Alternating current flowing in the primary (input) coil creates a continually changing magnetic field in the iron core. This field also passes through the secondary (output) coil and the changing strength of the magnetic field induces an alternating voltage in the secondary coil. If the secondary co ...
When the output voltage increases
When the output voltage increases

... The series element controls the amount of the input voltage that gets to the output. If the output voltage increases (or decreases), the comparator circuit provides a control signal to cause the series control element to decrease (or increase) the amount of the output voltage. ...
ZSCT1555 Precision single cell timer datasheet
ZSCT1555 Precision single cell timer datasheet

... going trigger pulse sets an internal flip flop which allows the capacitor to start to charge up via RA and forces the output high. The voltage on the capacitor increases for time t, where t = 1.63RACT, at the end of this period the voltage on the capacitor is 0.8 VCC. At this point the flip flop res ...
VR21 regulator troubleshooting
VR21 regulator troubleshooting

... A very small DC voltage passes develops over low resistance and high wattage R3 for overcurrent protection. One end of R3 is at ground (TB1-7), the other end very close to ground but not ground, the negative end of the bank of DC voltage (Q1 collector). Voltage transformation and full wave rectifica ...
discussion about the effects and dangers of
discussion about the effects and dangers of

Experiment 10: Inverting Amplifier
Experiment 10: Inverting Amplifier

... 2. Set trim pot value such that the output voltage of the op amp is equal to -3V when the input voltage is +1.0V. – Take a screen shot of the input and output voltage as a function of time, displaying at least 3 cycles. – Remove Rf from the circuit. Measure and record the resistance between pins 1 a ...
Current-Fed Multi-Resonant DC
Current-Fed Multi-Resonant DC

... in Fig. 4 in normalized form (degrees, referred to the switching frequency). A large (8) will reduce the current stressesof the transistors and of the rectifier diodes (equations 26 & 27 of APPENDIX II). However, a large (8) will decreasethe voltage transfer ratio and will therefore require a transf ...
ENERGY CONVERSION ONE
ENERGY CONVERSION ONE

... • since most syn. motors have brushless excitation systems mounted on their shaft, often these exciters can be used as starting motors • For many medium-size to large syn. motors, an external starting motor or starting by using exciter may be the only possible solution , because the connected power ...
ground fault neutralizer
ground fault neutralizer

EUP7903 数据手册DataSheet 下载
EUP7903 数据手册DataSheet 下载

< 1 ... 206 207 208 209 210 211 212 213 214 ... 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