Questions tagged [optical]
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58
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Problem with OMRON GV3M-31BR
Hi,
I was using OMRON GV3m-31BR to switch 24VDC at 2A(Max) and the 24VDC Switching signal was then used to control the relay by using the voltage divider as shown. The is switching as normal but as ...
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44
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Laser communication system to transmit Audio
The audio in these two circuits is only transmitted when they are both connected to the same battery (Vcc), and only the laser control audio level not the transmitting process.
When I connect the ...
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1
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61
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What is optical wireless communication? [closed]
What is the term optical wireless communication? According to my point of view, in optical communication there msut be a medium so the refractive index should be capable of keeping the wave inside the ...
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2
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49
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Delay logic of an optical sensor
I have a simple optical sensor that has 3 pins: Power (5V), Signal (5V when not triggered), and Ground. When the sensor is triggered, the signal goes to 0 V.
I need to constantly delay the signal by a ...
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1
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Optical switch LED-Photodiode
I was designing an optical switch based on a LED photodiode couple to detect the presence of an object between them. What i know is, for the LED:
Power dissipation [mW]
Forward current [mA] and ...
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Non-invasive bubble sensor
I'm trying to make a non-invasive bubble sensor. The liquid is going through a 3 mm plastic tube and the liquid is a clear saline solution.
I believe the easiest solution is an optical method using a ...
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65
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Optical distance measurement idea [closed]
Ok, so I posted this using my phone some time ago, more than a year ago. However let's just take it from the top, integrating the criticisms that I remember.
I am a cnc machinist by trade and we ...
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1
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101
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Experiencing undershoot with OPA857 transimpedance amplifier
I am trying to amplify an optical signal which comes from a photodetector in the range of 30 µA with a transimpedance amplifier (OPA857) followed by a variable gain amplifier (THS7530). The problem is ...
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69
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Increase speed to 9600-19200 in optical communication circuit
The circuit in the picture is the optical communication circuit of the RX. Currently, its maximum speed of communication is 2400. I want to increase the speed to 9600-19200. I have lowered the ...
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45
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What is the transfer function of electroabsorption modulators?
Can anyone give me a reference that I may find a closed-form formula for the output electric field (not power) in terms of the input small-signal electrical waveform (not input power) of an ...
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No light detected from 1310 nm IR optical transceiver AFBR-5813TQZ
I am trying to build a test application circuit for an AFBR-5813TQZ IR (1300 nm) optical transceiver. For now, I am only trying to verify that the transmitter works, so I have breadboarded the ...
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120
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I added a bias tee to a visible light communication (VLC) link for faster modulation. Why is there no signal coming out?
I am working on a simple VLC link.
A square wave input with 1 MHz signal is coupled with the direct current (DC) by a bias tee (mini circuits ZFBT-4R2GW-FT+) to drive the lighting of the white LED. ...
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1
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182
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Choosing the right LED IR and the photodiode for optical beam sensor
I need to design an optical beam sensor for about 15-20 cm of distance - any obstacle between an emitter and a detector would trigger an interrupt for a microcontroller.
I was thinking about using a ...
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1
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54
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Transceiver VCSEL failure analysis
We've had a number of optical transceivers fail recently and I am trying to track down the cause. It has happened with two different models: HFBR-53A5VSEMZ (now obsolete), and the TSP-D1CH2-C11.
Some ...
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Why does an optical channel require non-negative and real signal to transmit?
I'm trying to find an answer to two questions. In most of the papers they use the term without further explaining the reasons.
Why does intensity modulation require real and non-negative signals to ...
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Calculating minimum incident optical power when BER is given
I'm trying to solve this problem:
A silicon photo-diode has a responsivity of 0.6 A/W at a wavelength of 850 nm. Determine the minimum incident optical power at the photo-diode at this wavelength in ...
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Why is channel DC gain sufficient to model optical wireless communications?
I came across the following question at ResearchGate, but I fail to comprehend the answer to it.
The question states:
Why do we only study the DC gain in VLC channel modeling?
In all the papers and ...
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238
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My speaker connected to my TV is making weird noises only when playing videos [closed]
Apologies if this is the incorrect forum, if anyone knows of a better forum to ask on I would appreciate the redirection.
I have a very specific issue regarding audio playback from my TV. I have a ...
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2
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125
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Optical filters: What is the difference between Free Spectral Range (FSR) and the resolution based on (FWHM)
I have a question regarding the Free Spectral Range (FSR) and resolution based on (FWHM) of optical filters like based on Fabry-Perot-Interferometers.
As of now, I always thought of the resolution as ...
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530
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How do DVD players know how fast to spin?
Not sure if this is the right place to ask this, but here it goes: Different optical discs have different rotational speeds, based on the size of the pits and the bitrate. Newer disks have smaller ...
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63
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Link budget: receive power > 0
I want to compute link budget in free space laser communication.
My input parameters: wave length 700 nm, transmitter aperture: 0,88/0,15/0,2 m, receiver aperture: 0,3/0,5/1
My results:
I have a ...
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212
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USB-C to TOSLINK homemade (almost-) passive cord?
I'm trying to connect my phone to my portable DAC which has an optical in. I am looking for a solid 24-bit (up to 32-bit) cable for signal transmission, pre-processing. I've researched TOSLINK TX ...
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4
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296
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What is a modulated optical sensor?
I was told to try out a modulated optical sensor as a better and more "robust" option than the usual (unmodulated) optical sensors, saying the modulated ones are less subject to interference....
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What happens when we reach the maximun atenuation in Optical Networks Terminals (Optical fiber )?
Let´s suppose We have the following Optical Network Terminal :
According to datasheet, the receiver sensitivity is : -27 dBm
Now Let´s suppose We have the following fiber optical network :
As we ...
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Maximum Achievable distance, given the maximum delay, in optical fiber (single mode) and ethernet?
I have the following problem to solve. I have to find the maximum achievable distance between two nodes of a network, given the maximum delay possible between them. The connection can be single mode ...
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178
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Low cost position detection using a diy "encoder" [closed]
I'm building a machine that is adjustable, so there is this mechanical arm that can be in 5 different positions. I was thinking on building a custom encoder, I can easily make holes in each position ...
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Measurement of output current of a photodiode
I am a German student. My task is to conduct a characterization of a photodiode (KPEIMC-UDCOM by Kyosemi.) The photodiode will be illuminated by 850-1550 nm laser diodes. It would be good (but not ...
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130
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Optical pulse sensor not producing a clean TTL pulse
I have two of these optical pulse sensors monitoring LEDs on my electric and solar meters - Optical Pulse Sensor - Github
The first sensor outputs nice TTL pulses at 5V, the second sensor outputs ...
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4
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201
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Optical detection of a fan wheel
I want to detect the rotation speed of an impeller (fan wheel). Imagine a fan without a motor submerged in a liquid. This device is used for visual indication of liquid flow. I want to detect the ...
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What are the limits to parallel shift registers in electronics (in comparison to optics)?
Brackenbury and Mason in 1988 said, on comparing parallel shift registers in electronic and optical computing:
When implementing such a scheme in electronics, the shift length is usually limited to ...
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Photon lifetime in an optical cavity
Hi I have the following problem and data for an optical cavity.
Length \$ L=100 \mu m\$
Reflectivity \$R=0.33\$
Refraction index \$n=3.6\$
Inner losses \$p_i=20 cm^{-1}\$
Now I have to determine the ...
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ADNS-5050 components needed
I'm planning a project involving the ADNS-5050 optical mouse sensor package. The data sheet for this package says that it needs to be combined with 4 capacitors, and it has a diagramme that I think is ...
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Approaches to creating better mouse pointing hardware for absolute input?
I play the video game osu!. Osu! is a game that requires the player to quickly move the mouse pointer to different areas of the screen in a precise manner.
A game such as osu! lays out unique ...
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Using QSFP28 Module at Lower Lane Rate
I have an application that requires optical transmission of 4x16 Gbps SERDES lanes over fiber. A QSFP28 module for 100G ethernet seems like a great commercial solution--it can take the four lanes and ...
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How best to connect two optical limit switches to share one I/O pin
I'm trying to build a CNC laser engraver using a scrap industrial CNC gantry as a donor. The system already has optical limit switches for the max & min on each axis. I can't use the current ...
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Q-value in APD photodetector
I try to calculate the Q value of APD photodetector with these parameters:
$$R \hspace{0.1in} (response) = 1$$
$$M \hspace{0.1in} (magnification) = 10$$
$$k \hspace{0.1in} (ionization \hspace{0.1in} ...
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Selection of wavelength for optical reflective sensing
Most of the reflective sensors in the market use either red or near IR wavelength and have a very short range (in the range of mm). Given the reflectance of the Si at different wavelengths and ...
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Precision Current Sink for LED Modulation
I one of my first designs, I am attempting to simulate a high precision optical transmitter using an LED by varying the brightness in linearly with the incoming signal. The input signal is BFSK, ...
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Optical displacement sensor noise and current to voltage conversion
I'm currently involved in a project with the aim of measuring the tremor of mice limbs (displacements of about 100 um). The sensor my group has chosen is TCRT5000 (Vishay), but we are facing several ...
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Pachislo Token Sensor Optical sensor replacement part#?
Pachislo Token Sensor Optical sensor
As shown above I have a Pachislo Mazya Dynamite Kid's Machine which has a bad Token Sensor Booard. Can someone please advise on what a suitable replacement part ...
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Detecting movement of a mechanical ring using optical sensors
I need help deciding on which sensor to use for my current home project. Basically I'm trying to replicate the Numio Control but at much cheaper cost. If it is successful I will publish the result ...
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278
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How does one match irradiance to Luminous Intensity in Candela of source?
A light source has an Irradiance of about 1.6 W/m²/nm at wavelenght 385nm and an LED:
Peak Wavelength 385nm
Viewing Angle 30 °
Luminous Intensity 80 mcd
If this light source shines on a ...
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Optical Isolation of BNC trigger?
I am wondering if there is a more practical way to provide optical isolation for a BNC trigger. I am currently using the following: https://www.eagleharbortech.com/product-categories/fiber-optic-...
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How to Work with a Optical Fiber Ribbon
I got a piece of fiber optical cable that is in the form of a "ribbon cable" (see pictures). I have seen tools and procedures for making connections on a single strand of optical fiber. I would like ...
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Anyone got these optical encoders working? [closed]
I got these Optical Encoders from a local vendor and connected it to my arduino in the following order;
(+)----> 5v
(-)---> Gnd
(01)--->2
(02)--->3
But, it burnt and smoked out as soon as I ...
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SMD LED: How to calculate optical power (in mW) from luminous intensity (in mcd)?
I chose an LED for my application but I need optical power, in mW.
In the data sheet, luminous intensity is shown in mcd but I did not find formulas for calculation although there are graphs, etc.
...
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638
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I've seen many conflicting answers online: For optical storage, does a pit represent a '1' bit or does a land represent a '1' bit?
I've seen many conflicting answers online so:
When reading an optical disk, which one of these is true:
A 'pit' represents 1 and a 'land' represents 0
or
A 'pit' represents 0 and a 'land' ...
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Water level measurement using Optical Mouse Sensor
I wonder if anyone has hacked an Optical Mouse sensor to measure water level in an overhead water tank? Its possible to read frames data from the sensor and if those frames could be processed with a ...
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Opto switch for detecting translucent polypropylene
I am building a liquid handler (a CNC machine that pipettes small quantities of liquids). The machine switches polypropylene "tips" between pipetting different fluids. Positional accuracy within 0.5mm ...
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How come optical data modulation is faster than that of electrical modulation while optical modulation is done by electricity?
why optical data is of high bandwidth that that of electrical copper data bandwidth when we use electrical signal to achieve optical data modulation ?
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