Questions tagged [uv]

Ultraviolet electromagnetic radiation, which has a shorter wavelength than visible light. Use for questions about ultraviolet radiation in the context of electronics design, such as the use of ultraviolet emitting LEDs, erasure of EPROM using ultraviolet, etc.

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UV masking with an LCD

I am planning to make a machine that uses an LCD screen as a mask for etching PCBs. However, I am concerned about the type of LCD that I would need as well as the accuracy that I would get. My main ...
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Transparent displays that allow UV light/sunlight to pass through them?

Is there a type of digital display that can work to let sun through it, so that the dark pixels block the UV, and transparent pixels let the UV through? I'm aware of monochrome LCDs for a resin ...
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Are ultraviolet LEDs used in consumer lights? (xmas lights)

I took apart a bulb on this strip of purple christmas lights and was surprised to find that the LEDs inside are actually purple 3mm LEDs. Naturally, I looked into some replacements but then the ...
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Removing collected charges in a IC CMOS circuit exposed under a 30keV electron beam source

I would like to know if there is any mechanism (for example UV light exposition) to remove charges collected in an IC CMOS circuit that was exposed under a 30keV electron beam source. Presumably, ...
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UV-C lamps flickering problem

I have got 8 UV-C lamps connected to a portable battery(AC) through a smartplug. I am using 4 UV Ballast with 2 lamps connected to one ballast. I am controlling the lamps with help of a wireless ...
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Supervisory watchdog to assure UV LEDs are off and stay off during non-use

I'm designing a circuit consisting of 3 pairs of LEDs. Each pair has one UV-LED and a white LED. The pairs will be turned on consecutively and for about 1 second each. Between each use there will be ...
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Coin cell UV pendant Q2 [duplicate]

I am a beginner with LED lights, but would like to use a 5mm 365nm UV LED diode to make a pendant with a small fluorescent crystal. I would like to create a very simple, very compact circuit with a ...
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Coin cell to power a 5mm UV LED?

I am a beginner with LED lights, but would like to use a 5mm UV LED to make a pendant with a small fluorescent crystal. (This is what I purchased (https://www.amazon.com/uxcell-365-370nm-Ultraviolet-...
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How to calculate the time needed for the UVC to be turned on and disinfect a specific space/location?

I have 3x60W UVC tube with a 254 nm wavelength. I want to know until up to what meter the range will cover and disinfect the area and how to calculate the time needed for these 3 tubes to be turned on ...
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Pass bandwidth of backing light for LCD display

A stardard industry LCD display is composed of several parts. Polarizer film and color filters produce and image by masking the light from a source positioned behind the LCD itself, the so called ...
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Electrostatic arc safety

I'm experimenting with early electrostatic devices, and I'm measuring spark gap length to determine voltages generated. How dangerous is it to observe these arcs with the naked eye? Should I wear ...
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Getting the optical power of a UV-LED using a spectrometer data

if it is possible can you let me know the way to get the radiated power of a UV-LED using the output data from the "Ocean optics- Maya pro 2000" spectrometer, or the calculations needed to ...
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UVC Lamp causes Atmega 328P to malfunction

I have got an Atmega328p which connected to a TFT LCD 1.3 inch using SPI. The Atmega 328P is powered through a 5V adaptor. The problem is most of the time when I switched on the UVC Lamp the LCD will ...
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UV protection for character LCD

I am using 20X4 character LCD display. Like these: https://www.alibaba.com/product-detail/big-size-20x4-line-white-color_62471561311.html?spm=a2700.pc_countrysearch.main07.78.2bafd2a7u344W2 The ...
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can you turn a visible laser pointer into a uv one?

I was wondering if there is anything I can do to make a visible laser pointer uv with (or without) messing with the laser. like if I simply shot the laser pointer through some device or screen that ...
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Problem with understanding EPROMs and how they're written to

I've got a problem understanding how an EPROM (UV-erasable) works. This question may seem very dumb, but what would happen, if I just try to write contents to an EPROM, which has already been written ...
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How to specify UV high brightness LEDs?

I'm trying to find high brightness UV LEDs appropriate for this project: https://www.instructables.com/id/UV-LED-Exposure-Box/ which includes: "The most critical parts of this project are the UV ...
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How to power a 17W T5 Germicidal UVC Lamp?

I recently bought a SBL 350T Germicidal Lamp from American Ultraviolet, but have been having some trouble finding out how to power the lamp since I do not have much experience in lighting and the base ...
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Removing the phosphor coating in fluorescent lamp

Any ideas on how to remove the inner phosphor coating on the inner surface of fluorescent tube lamp turning it into a UV lamp?
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Measure distance to object with angular precision - invisible for camera

I want to build myself an arduino based follow-focus. There is one mode intended for using a joystick for manual control of focus and zoom. This code already works a treat. Now I want to add a ...
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How to power bulbs expecting 24V AC from a car's "cigarrete" socket?

I'm turning the trunk of my car into a UV-sanitizer chamber -- so that, by the time I return from the supermarket, the bags and the packages handled by strangers there are sterile. To this end I ...
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How to power 83V UV-C germicide tube?

I'm currently working on a UV-C germicide lamp, and among the things I have to do, is to drive four 83V OSRAM 21283 G55T8/OF 55W G13 T8 Tubes. Here's a link to the tube, and the datasheet. My ...
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Covid-19: can a UV-C source be improvised from a standard mercury vapor lamp?

I suggest it because the usual professional UV-C sources are in short supply and very costly. A common 175 W mercury lamp designed for illumination includes the quartz 'lamp' tube itself, inside an ...
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Repurposing CFL ballast for different bulb (UVC)

I am attempting to repurpose the (electronic) ballast contained within a CFL lamp to power a UV-C bulb (mercury discharge, uncoated tube) for disinfection purpose, and out of general interest in ...
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Are these UV-C tubes meant to be run only on pure AC ballast?

I’ve this portable small T5 4W UV-A 300-400nm black light tube lamp with me. I’m trying to see if it’s possible to use a 4W UV-C lamp in the same fixture. But I noticed that the lamp has the violet ...
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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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Can I use USB to power a flashlight that runs on 3*AAA or 1*18650 battery? [closed]

I am thinking of buying this UV flashlight. It runs on either 1 18650 battery (4.2v) or 3 AAA batteries (4.5v). Since the flashlight can already take 4.5v, will it be safe to run on 5v USB? I found ...
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LCD for SLA 3D Printer Resin Curing

I'm doing some research on what types of LCD displays can be used to filter and pass UV light for resin curing - specifically in the context of building a DIY 3D SLA printer. The community commonly ...
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Magnetic ballast with g23 bulb with capacitor

I am trying to make a UV-b photo-therapy light and want to make sure I'm understanding the circuitry correctly-so i don't hastily burn a $50 bulb. Im using a Phillips PL-S 9W/01/2P (link here). It's ...
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3 votes
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Ultraviolet sensor response curve

I did a search on "ultraviolet sensors" in this forum, and came up with only three results, so, it appears, that this has not been asked before. I have a hand-held ultraviolet light sensor from ...
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Can an EPROM be "refreshed" without UV erasing?

I have lots of AM27C512 EPROMS (with the UV window) which are quite old (1980's.) Using a Xeltek SuperPro 3000U, most can still be read and verified. A few have failed outright and were replaced. ...
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UV light masking and LCD screens

Not sure if this is the right stack to ask this question on, but it relates to an engineering project that I and a student electrical engineer are starting. Can an LCD screen be used as a masking ...
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Can you damage an LCD screen with a camera flash, high-powered flashgun/speedlight?

I'm curious as to what the limitations are in regards to uv radiation on LCD screens when subjecting them to high intensity light sources such as camera flashes (such as a nikon or canon speedlight). ...
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Safety of "UV" LED

I am curious as to whether LEDs like these ones http://www.led4everything.com/catalog/product/view/id/410/s/st0028/ are harmful, they are advertised as UV. But are they just purple LEDs or actual UV? ...
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g23 socket and 11W UV-C bulb

because UV-C machines tend to be expensive, our lab working on biological/biochemical research has reverted to attempting to build a machine from scratch. Therefore, we recently purchased a G23 ...
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uv light dc current [closed]

I am working on a project which uses UV rays to kill bacteria in water and make it safe to drink. The people who would use this do not have access to an AC source, so I need the UV Light source to be ...
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How could I amplify the output from this UV photodiode sensor

I have been able to use the following photodiode sensor board to detect changes in the output of the sensor when a UV plasma is active. However, changes sensed when the UV plasma is active are very ...
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The current state of UVC LED technology

I saw this kickstarter for a self cleaning water bottle. It's a pretty good idea, and is physically plausible, but I'm a bit skeptical about their UVC LED. UVC LEDs do exist (and they have a picture ...
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Battery setup to power UVC bulb with 12 V DC at 1 A

So, I'm looking to power this UVC bulb kit: The device size overall needs to be pretty small. (I'm trying to mount the bulb in the top of a cup-shaped housing. Ideally, the battery supply would be ...
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1 vote
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How to test a pond filter UV lamp and ballast?

I bought a new UV lamp for a pond filter but I don't see any light from the inspection lens in the lamp holder. I checked the the connection in the socket and I see 240v. Does that mean the ballast ...
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How determine the number of LEDs that I need?

So I am trying to do some calculations for a UV curing system that the place I am interning for is working on. One of the tasks that I am assigned to is to determine how many LED does the system need ...
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Weird behavior of phototransistor

Tonight I debugged a weird issue with a simple IR LED/phototransistor circuit that I was meaning to integrate in a RPM sensor. With the IR LED pointed towards the phototransistor, with a gap of 1-2cm ...
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Is it possible to detect specific UVB wavelength ranges using just a UVM-30A UV sensor or similar

Is it possible to detect specific UVB wavelength ranges using just a UVM-30A UV sensor or similar. The spec sheet for sensor GUVA-S12SD. Seems to indicate that it generates a specific current level ...
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Time required for toner transfer vs UV light for manual PCB fabrication

Me and my group mates is currently on our planning stage of our design project in the fourth year of our program. We are going to make a direct sketch to PCB printer using CNC. I just want to ask, ...
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UV intensity behaving oddly with ML8511 UV Sensor

I am using the ML8511 UV sensor: https://learn.sparkfun.com/tutorials/ml ... -guide/all The sensor outputs a number that represents UV irradiance (intensity) in mW/(cm squared). However, whenever I ...
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Developing photoresist PCB with UV bank note checker

I'm just looking into developing a photoresist PCB. I bought a kit that contains a photoresist single sided PCB, developer solution (in powder form to mix with water), etchant, and a tank. I have ...
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Can spray paint or a marker block UV for solder mask/resist? [duplicate]

I am planning to make a PCB and putting solder mask on it but I don't have my own laser printer to print the transparency for the mask. I do, however, live near a printing shop with a laser printer ...
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LED lamp loses intensity very fast

I have designed a UV lamp using UV LEDs (VAOL-5EUV8T4-ND), and it loses intensity very fast. I attach a figure with a picture of the lamp and the circuit. I am using a LM317 to generate a constant ...
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signs of complete PCB photo-resist development

Currently. I'm making a PCB using the photolithographic method (print on transparency, expose with UV which works, then develop under a bright red LED as the only light source), but half the time, the ...
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6 votes
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LED intensity changes with time

I want to operate a UV LED at continuous 20mA for one week. However, when I measure the LED intensity with a photodiode (see image), I find that the light intensity changes continuously in time. I ...
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