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Questions tagged [wave]

May refer to an electromagnetic wave (such as a radio wave) or the PCB manufacturing process of wave soldering.

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How to connect the transformer in this three-tube DC regenerative shortwave radio from aliexpress?

I've bought a three-tube DC regenerative shortwave radio on Ali-Express/China just to try building. As far as I can tell all the parts are here except for one thing. A schematic. Has anyone tried ...
Rick Steiner's user avatar
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1 answer
27 views

Can a photon be modeled using AC driven electron and AC driven wire loop?

Can a photon ("electromagnetic wave packet") be simulated in software as an electron bouncing up and down (for the oscillating E field) and a loop of electrons with neutralized electrostatic ...
user323947's user avatar
0 votes
1 answer
37 views

Voltage in the transmission line

In a power transmission line, the voltage at any point in the transmission line (along the length)is said to be the sum of the incident and reflected wave components of voltage. And if it is such then ...
Jina's user avatar
  • 99
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0 answers
44 views

Transmision and coupling coefficient in waveguide and ring resonator

A simple ring resonator with a bus waveguide is described by: \begin{equation} \begin{pmatrix} B \\ C \end{pmatrix} = \begin{pmatrix} t & \kappa \\ -\kappa^* & t^* \end{pmatrix} \begin{pmatrix}...
Sajadi's user avatar
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4 votes
5 answers
486 views

Contradiction between wave impedance mismatch and transmission line theory

Suppose we have two transmission lines connected with each other, each transmission line has the same characteristic impedance: $$ Z_0 = \sqrt{\frac{L}{C}} $$ however they don't have the same ...
rr1303's user avatar
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1 vote
1 answer
60 views

Wave Propagation: Attenuation Constant in a Lossless Dielectric

I am referring to M. N. O. Sadiku, Elements of Electromagnetics, 7th ed: In chapter 10, the expression for the attenuation constant α in Np/m in a lossy dielectric is derived as: $$ \alpha = \omega\...
Ryan's user avatar
  • 111
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0 answers
19 views

How are the currents induced by the E-field and H-field flows on a sphere? [duplicate]

Please correct me if I am wrong? We consider a sphere made of thin metal, with a radius of 1 m, at 20 km distance from an AM transmitter operating at 1 MHz. The alternating current in the transmitter ...
HAPU's user avatar
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0 answers
47 views

Solder Wave Residue

Issue: 1-3 days after maintenance, chunks of solder residue starts to show in the solder wave bath. This creates blockage in the nozzle. Any notes how to solve this problem? Notes: No new chemicals ...
l-Inġinier's user avatar
0 votes
3 answers
254 views

XR2206 Signal Generator breaks up and distorts badly all waveforms

I just put together this signal generator with a xr2206 DIY kit, single supply, tried 9,6V smps first (too low!), then w/ checked speced minimum 12V DC Li-Ion Vcc, same behaviour, distortion/unstable. ...
rantoniusw's user avatar
0 votes
1 answer
86 views

0-12V square wave to linear 12V

Can anyone help me with the design of circuit? I need to use a zero to 12V square wave input and output a linear or straight 12V to carry 2 amperes. I think a collection of capacitors and an inductor ...
Josh 's user avatar
2 votes
2 answers
185 views

How can a Faraday cage absorb and reflect waves, yet antennas mostly absorb and can be used on signals?

I understand they are very different in structure but comparing a simple monopole to a Faraday cage, they both are constructed from metal. Why is it the sides of the Faraday cage absorb the waves and ...
George kirby's user avatar
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3 answers
100 views

Electrical wave propagation in wire vs space

Does it take the same amount of time for the lamps to turn on? Or does it take three times longer for the right lamp to turn on?
Amir Za's user avatar
0 votes
1 answer
72 views

What is the actual physics and reasoning for the “Ground plane” underneath a GPS patch antenna

From my very limited knowledge of EM, I believed that anything tied to earth can absorb radio waves, so if an antenna was to be placed above a ground plane, why does the ground plane not just absorb ...
George kirby's user avatar
1 vote
0 answers
150 views

Square wave rectified output value calculation

I can understand the ground osc probe but with a hand osc I shouldn´t have that problem, I think. But It went even worst. Maybe it is a doubler¿?
XanDasXuras's user avatar
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1 answer
166 views

Please help me understand this amplitude modulation LC oscillator

I have a problem understanding the circuit below where the LC oscillator is used to produce the negative cycle wave for the amplitude modulation. I am having a difficulty in grasping the fact that the ...
kam1212's user avatar
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0 votes
1 answer
51 views

Phase Differences and Wave Equation in ULA Antennas with Far-Field Assumption

I am analyzing a signal received by two antennas, where the second antenna is positioned farther than the first in the direction of wave propagation. I am encountering some confusion when it comes to ...
Naetmul's user avatar
  • 285
1 vote
2 answers
2k views

What can I use to convert the output wave from an inverter from a modified sine wave to a pure sine wave without much energy loss?

I use an inverter (600 W) to convert from DC 12 V to AC 220 V 50 Hz, but the wave output from the inverter is a modified sine wave, which causes problems when operating some electrical appliances (...
MOHAMMED's user avatar
1 vote
1 answer
47 views

Which characteristic of an interface allows an ultrasonic sensor to work?

Say I have two liquids in a vat and I want to use ultrasonic to determine what height the interface between the two liquids is. What is the actual liquid property that causes the sound waves to ...
InBedded16's user avatar
0 votes
3 answers
132 views

Capacitor Operating Temperature Range

Our .0047uF G 630 Vdc axial cap has an operating range of -40C - +85C. If the wave solder temp reaches 105C won't the cap be damaged, or possibly have an altered tolerance range?
Steven Carpenter's user avatar
0 votes
0 answers
65 views

Why would 50W of power be sent to be reflected in the first place to an open end antenna port to be reflected [duplicate]

I understand theres a lot online about transmission line theory it terms of why the reflection, but if say the load was open or really high, thinking of a standard circuit, the total series inpedance ...
George kirby's user avatar
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0 answers
103 views

How can I measure the frequency of multiple square waves?

I'm trying to evaluate the frequency of 18 independent sources of square waves in my system (the signals are generated independently as feedback.) Basically, I need to have a way to use one ...
TFO's user avatar
  • 3
-1 votes
1 answer
838 views

Could a DIY 1 kW portable version of the military non-lethal microwave beam active denial system (ADS) be made?

How would one create a portable 1 kW microwave emitter that projects out a 95 GHz beam to about 5 - 10 feet? What kind of components would be required? I recently came across this fascinating video ...
emtinkerer's user avatar
0 votes
2 answers
199 views

How to generate microwave band frequencies like 85GHz? Is there a DIY device or parts kit to do this? [closed]

Let's say I want to build a device that generates and sends out a microwave of some arbitrary specific frequency to a short distance, say 1 - 2 feet. For example, 95 GHz. Is there a straightforward ...
emjunkie's user avatar
1 vote
0 answers
61 views

Formula relating attenuation and loss tangent in EM wave propagation?

in this previously answered question, a relation is established between the attenuation and loss tangent in EM waves. The formula given is the following: $$ \alpha = \frac{\omega}{c} \cdot \sqrt{\frac{...
Jes's user avatar
  • 111
1 vote
1 answer
53 views

Effects of ferrite isolator on waveform

I have recently measured the standing wave signal from a waveguide. I notice that as the frequency is lowered the signal tends towards a sawtooth wave. ** My guess for why this happens is that the EM ...
dk30's user avatar
  • 11
0 votes
2 answers
123 views

Do electromagnetic fields undergo any variation between fields in time, or do such waves just expand in time and in their spherical plane?

In literature it is routinely said that an electric field generates a magnetic field, and thus one field creates the other "eternally", and that this explains their propagation. Am I wrong ...
JrBennito Bennito's user avatar
0 votes
1 answer
59 views

Nodes are moving. Can it be called a standing wave?

Please see the following youtube video. https://youtu.be/MJKfyLfY9Pg It is a lossy transmission line. The resultant wave of incident and reflected wave is also moving. In a standing wave, neither the ...
user avatar
0 votes
1 answer
154 views

I need a way to use analog electronic components to invert an irregular wave [closed]

I am doing a personal project wherein I am using an EMG sensor on my muscles, amplifying the output, and then running it to a lead on a motor. What I can't figure out is how to invert the irregular ...
Universal82's user avatar
1 vote
1 answer
571 views

Generate a sine wave with MCU

I want to generate a sine wave without an offset voltage. I generated a sine wave from 0 to 3.3 V and it has a 1.65 V offset. I need a sine wave from -1.65 V to 1.65 V using an MCU. How can I do that?
Ali Buğra ÇETİN's user avatar
3 votes
6 answers
854 views

Why does this inverter use two bridges?

I recently destroyed a 1000 W-rated 24 VDC -> 220 VAC pure sine wave inverter I bought a while back from Ebay, by connecting its output to mains power inadvertently. Afterwards, I decided to ...
John Doe's user avatar
0 votes
1 answer
160 views

Using An nRF24L01 Module With A 2.5GHz 5dBi Antenna?

I have a basic knowledge about Communications and Antennas, so i was wondering what will happen if i used a 2.5GHz 5dBi antenna instead of a 2.5 GHz 3dBi one?![Images Are Listed Below]. To be specific,...
A_Asaker's user avatar
0 votes
0 answers
269 views

125 kHz Arduino RDM6300 read issue

I've tried to read a 125 kHz signal with an Arduino using an RDM6300 module, but it didn't work. I tried to catch the signal with Audacity. Please find attached photo with the signal. How can I catch ...
Zilvinas's user avatar
0 votes
0 answers
119 views

Square waves (Hall-effect sensor)

I'm replacing the gearbox of my truck. Both gearboxes (the old one and the new one) have speed sensors in the output shaft, but they don´t produce the same signals. In order to make the new sensor ...
Jota Ce's user avatar
3 votes
1 answer
241 views

Reflected wave phenomenon - transient response and steady state of a transmission line

I'm currently trying to design a PWM driver for an impedance-mismatched long cable. Sending rectangular pulses (rise-fall time ~0s) over a long cable that is not matched with its impedance results in ...
Kilian's user avatar
  • 39
0 votes
2 answers
235 views

Need 64Hz square wave green LED driver for a mosquito zapper

I have several 10 watt COB (Chip-on-Board) green LEDs which apparently are the best color to attract mosquitoes if driven at an ideal pulsing square wave frequency of 64 Hz. I was going to use a ...
Robert Sole's user avatar
0 votes
1 answer
774 views

Square wave distortion at low frequencies, high-pass filtering, AC coupling

This is an update on my previous question. As Hearth suggeste, I changed to DC coupling on my scope. This is what I got: That's a clear change. Not a perfect square waves but I guess it is because of ...
kawasaki997's user avatar
0 votes
1 answer
796 views

Square wave distortion on low frequencies

I have this old Soviet low frequency sine and square pulse generator "G3-36A". I ran into an interesting problem. When I try to generate square pulse under 100Hz I get a distorted wave. ...
kawasaki997's user avatar
7 votes
5 answers
2k views

Rail to rail +12/-12 V square wave generation with microcontroller

I need to generate a +/-12 V square wave, +/-0.4 V tolerance is allowed. The purpose is to drive the pilot signal of an electric vehicle level 2 charger, for those curious. EDIT (clarification): what ...
jamarju's user avatar
  • 311
0 votes
1 answer
152 views

Sort of square wave shift or cleanup

I have a wave I want to feed into an Arduino to measure frequency. I need the wave to hit zero to measure the frequency, I think. A nice clean square wave ideally. I am using a simple 4.3V Zener ...
crazyquiff's user avatar
-1 votes
2 answers
270 views

Converting square wave into a sine wave [closed]

I am trying to convert a 1 MHz square wave into a sine wave of the same frequency. What's the best way to achieve this?
RafaelCachetas's user avatar
2 votes
3 answers
406 views

1 Hz ring oscillator not working

Inspired by this project I built a ring oscillator that outputs a 1 Hz signal. Using their formula, I decided to use 1K for R1 and R2, and 558 uF for C1. I used a CD4069UB CMOS inverter that has a ...
MuGa's user avatar
  • 33
0 votes
3 answers
175 views

Problem in the book "Radio Antennas and Propagation"

I came across a problem in an electronics textbook by William Gosling, Radio Antennas and Propagation. I am an undergraduate and I sent this to my lecturer to help solve but unfortunately, her answer ...
Finance_sav's user avatar
2 votes
3 answers
1k views

Frequency of square wave generated by Wien bridge oscillator

I have designed the wien bridge oscillator circuit for 20Hz square wave generation. It gives a 20Hz sinusoid as output when I keep the non-inverting amplifier gain 3V/V. But when the non-inverting ...
Wanderer's user avatar
  • 179
3 votes
3 answers
2k views

Circuit that converts sine wave to RMS voltage

How do I design a simple circuit that converts a sine wave to an RMS voltage? The input will be a sine wave and the output an RMS voltage. I know I will need an ADC, but not sure which one. I also ...
user361403's user avatar
2 votes
1 answer
74 views

EM radiation hitting atoms [closed]

What happens when the EM wave is incident on a atom? Do the de-localized electrons in the atoms or the valence band electons move in the direction of the electric field? Also when the electrons move, ...
ThreadBucks's user avatar
4 votes
2 answers
103 views

Photodiode square wave positive duty cycle lower and lower

I drive an IR LED with a 50% duty cycle square wave and receive its signal with a photodiode. If I take the photodiode farther and farther from the LED, the signal's positive duty cycle is lower and ...
DJDB999's user avatar
  • 77
1 vote
2 answers
509 views

Double conversion UPS off a modified sine input?

I have a 2000W modified sine wave inverter running from 12V bank in a tractor-trailer. It’s company owned, so no changing or adding equipment. Only viable solution I can see to achieve a sine wave is ...
C59's user avatar
  • 19
3 votes
3 answers
2k views

Precise square wave generator 32768 Hz

I need to create a circuit to generate a square wave with 50% duty at 32768 Hz +/- 5 Hz. The output of the circuit will drive an NPN transistor ( 0.2 A , 24VDC ). The cost of the component is not a ...
Video Ispezioni S.r.l.'s user avatar
-1 votes
1 answer
161 views

How to plot graph of perpendicularly polarized uniform plane wave is incident obliquely on a dielectric to conductor boundary using Matlab

I am writing the code for the equation which is attached below ( image of equation). I have written the code but getting errors. I want to plot the graph of E and H as underlined in the image. In the ...
Segmentation fault's user avatar
0 votes
1 answer
120 views

WiFi (2,4G) Antenna Isolation. Why 3 capcitors version does not work

I need to isolate the antenna from the WiFi transmitter. There are some solutions on the market but none suitable for my application. So I have started some experiments. 2x PCBs creating DIY ...
0___________'s user avatar
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