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Questions tagged [uv]

The tag has no usage guidance.

-1
votes
0answers
33 views

A suitable UV source [on hold]

I am working on a photocurable resin , which reacts when exposed to UV light, i need a UV light source(365nm) which can be focused easily and also the intensity can be varied through some mechanism, ...
3
votes
4answers
180 views

Can an EPROM be “refreshed” without UV erasing?

I have lots of AM27C512 65k x 8b 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 ...
2
votes
2answers
64 views

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 ...
0
votes
2answers
94 views

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). ...
0
votes
2answers
184 views

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? ...
0
votes
1answer
30 views

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 ...
0
votes
1answer
84 views

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 ...
1
vote
6answers
274 views

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 ...
0
votes
1answer
176 views

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 ...
0
votes
2answers
79 views

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 ...
0
votes
0answers
115 views

How to measure UV LED wavelength? Experimental setup help

I'm planning on doing research with UV LEDS, and one of the important issues I'm finding is that each singular UV LED comes with it's own set of % error. Reading papers I find that researchers are ...
1
vote
1answer
729 views

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 ...
3
votes
4answers
102 views

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 ...
0
votes
1answer
315 views

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 ...
0
votes
2answers
60 views

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 ...
0
votes
1answer
65 views

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, ...
0
votes
3answers
273 views

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 ...
0
votes
2answers
135 views

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 ...
0
votes
1answer
231 views

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 ...
-1
votes
2answers
256 views

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 ...
3
votes
2answers
163 views

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 ...
6
votes
4answers
1k views

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 ...
0
votes
2answers
122 views

Is there a such thing as a UV EPROM whose contents cannot be burned unless the UV-sensor is uncovered? [closed]

Is there a such thing as a UV EPROM whose contents cannot be burned unless the UV-sensor is uncovered?
2
votes
1answer
407 views

PCB UV Etching Paint

Is the UV curable paint used for PCB etching the same UV curable paint used for making PCB solder masks? Some have different eBay descriptions but they're all in identical 100g black containers. As ...
3
votes
1answer
804 views

Is it possible that my UV LED is emitting white light? If so, how would I filter out the white light?

I recently purchased a 365 nm UV LED, and set up the proper circuit. When I turn the power on, the LED lights up very dimly. Is this white light (that's the color I saw) being emitted from the LED? ...
2
votes
2answers
2k views

Using a CFL ballast to power 9W UV tubes

I would like to build a low-cost home UV exposure box for PCB manufacturing. Recently my attention was brought to these dirt cheap UV bulbs which are used in manicure drying lamps. I have the ballast ...
1
vote
1answer
98 views

Forward voltage of AlN diode

At 210 nm, the shortest wavelength/highest frequency LED seems to be composed of a Aluminum Nitride junction (according to this article). I was wondering, what would the Vf (forward voltage) be of ...
1
vote
3answers
254 views

UV Led / Did I get Harmed?

There was an UV Led lying around, I wanted to check bank notes with it. I soldered a 3W led on PCB. And powered it with 4 AA batteries (connected in series) The light was bright and purple. (I mean, ...
0
votes
1answer
376 views

UV LED operating above Designed Voltage Hazard?

I have a 5mm High Brightness UV Led that I bought from Radio Shack that states Wavelength 405nm ( typ) View angle 20 Degrees FW current 20mA FW supply 3.3V ( typical), 4.0V (max.) part # 276-0014 pkg....
18
votes
3answers
27k views

Are UV LEDs really dangerous?

I just bought some UV LEDs I bought them for testing banknotes and identity papers. I read the documentation and saw some warnings about UV light in which the vendor advises not to look directly at ...
1
vote
1answer
462 views

How many of these UV lamps do I need for PCB fab?

I want to build a PCB UV exposure unit. It will be in a wooden box, it will have lamps and a glass above them. Basic design. For the lamp drivers I will use the circuit from the neon lamps at home. ...
2
votes
1answer
398 views

Dot Matrix IC message board [closed]

I'm trying to make a dot matrix message board -type thing work, The dot matrix IC's are the DL-57 Alpha Numeric Dot Matrix Display [Data Sheet] : https://drive.google.com/file/d/...
0
votes
1answer
262 views

how to print a PCB layout for UV etching

I am new to UV etching. I have a 2 layer PCB layout that I prepared on Eagle Cad. I am confused what layer do I need to mirror? After printing the layout what side of the paper turns to the UV light ...
3
votes
1answer
951 views

Determining the best UV exposure time

I would like to manufacture DIY PCB. I am planning to make a UV box like on this link, then I wonder how I can determine the best UV exposure time? or if I use the Sun as the UV source, how I can ...
6
votes
1answer
979 views

Solar UV index radiation sensor?

I need to measure solar Ultra Violet radiation index. Is there any light sensor that would allow me to do this using an Arduino?
7
votes
1answer
443 views

6x UV-leds in parallel turning on and off when they should be on all the time

I have 6x UV-leds in parallel driven by a 6V source. The problem I have is that they glow for a little while, then they are completely off for a little while, then glows and then they are off ...
1
vote
1answer
1k views

DIY UV Exposure Unit for Making PCBs

I'd like to buy or build a UV exposure unit for the photoresist method of making my own PCBs. Nice-to-haves: adjustable timer knob works for double-sided PCBs US$50 budget What are my options?
2
votes
2answers
1k views

Good high-lumen LED suppliers? [closed]

I'm looking for some bright LEDs (in the range of 30-50 lumens, which I think means 2-3 W) for use in a piece of scientific equipment. Can anyone recommend an LED manufacturer that has not just ...
0
votes
2answers
428 views

Light Modulation and Detection

IR light is the mainstay frequency for optical communication systems. How could I experiment with UV frequencies doing the same thing? Ideally I want to set up a serial link just as is often done with ...