EXPOSING MYSELF - UVC Radiation EPROMs
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- čas přidán 4. 06. 2022
- WARNING: Safety glasses or suitable welding helmet and gauntlets must be worn at all times when watching this video. I take no responsibility for those failing to use suitable personal protection equipment.
In todays video we are going to be talking about two types of Ultra Violet (UV) radiation and there various uses for making printed circuit boards, germicidal applications and also how UVC can be used for erasing Eprom devices
EPROM:
An EPROM (rarely EROM), or erasable programmable read-only memory, is a type of programmable read-only memory (PROM) chip that retains its data when its power supply is switched off. Computer memory that can retrieve stored data after a power supply has been turned off and back on is called non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages than those normally used in digital circuits. Once programmed, an EPROM can be erased by exposing it to strong ultraviolet light source (such as from a mercury-vapor lamp). EPROMs are easily recognizable by the transparent fused quartz (or on later models resin) window on the top of the package, through which the silicon chip is visible, and which permits exposure to ultraviolet light during erasing
All radiation is a form of energy, most of which is invisible to the human eye. UV radiation is only one form of radiation and it is measured on a scientific scale called the electromagnetic spectrum
UV radiation is only one type of EM energy you may be familiar with. Radio waves that transmit sound from a radio station’s tower to your stereo, or between cell phones; microwaves, like those that heat your food in a microwave oven; visible light that is emitted from the lights in your home; and X-rays like those used in hospital X-ray machines to capture images of the bones inside your body, are all forms of EM energy.
The most common form of UV radiation is sunlight, which produces three main types of UV rays:
• UVA
• UVB
• UVC
UVA rays have the longest wavelengths, followed by UVB, and UVC rays which have the shortest wavelengths. While UVA and UVB rays are transmitted through the atmosphere, all UVC and some UVB rays are absorbed by the Earth’s ozone layer. So, most of the UV rays you come in contact with are UVA with a small amount of UVB.
Like all forms of light on the EM spectrum, UV radiation is classified by wavelength. Wavelength describes the distance between the peaks in a series of waves.
• UVB rays have a short wavelength that reaches the outer layer of your skin (the epidermis)
• UVA rays have a longer wavelength that can penetrate the middle layer of your skin (the dermis)
UVC radiation is the highest energy portion of the UV radiation spectrum.
UVC radiation from the sun does not reach the earth’s surface because it is blocked by the ozone layer in the atmosphere. Thus, the only way that humans can be exposed to UVC radiation is from an artificial source like a lamp or laser.
UVC radiation can cause severe burns of the skin and eye injuries (photokeratitis). Avoid direct skin exposure to UVC radiation and never look directly into a UVC light source, even briefly. Skin burns and eye injuries from UVC exposure usually resolve within a week with no known long-term damage. Since the penetration depth of UVC radiation is very low, the risk of skin cancer, cataracts or permanent vision loss is also thought to be very low. The type of eye injury associated with exposure to UVC causes severe pain and a feeling of having sand in the eyes. Sometimes people are unable to use their eyes for one to two days. It can occur after a very short exposure (seconds to minutes) to UVC radiation.
Some UVC lamps emit small amounts of UVB radiation. Therefore, exposure to a high dose or prolonged low dose of radiation from some UVC lamps can potentially contribute to effects like cataracts or skin cancer that are caused by cumulative exposure to UVB radiation.
Additionally, some UVC lamps generate ozone which could cause irritation to breathing passages (that is nose, throat, and lungs), particularly for those who have respiratory sensitivity such as asthma or allergies. Exposure to high levels of ozone gas may also worsen chronic respiratory diseases, such as asthma, or increase vulnerability to respiratory infection.
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www.megauk.com
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Some vital information on that EPROM 🤣😂👍
Thanks for watching and comments. Best regards Chris
Classic flash back memory ... yep we used that box with ready made UV sensative PCBs and the spray, at the Uni back in the 80s ... gotta love the 'old' RS Components ...
I have such a lot of parts and tools from RS back in the day. Thanks for watching and comments
Much enjoyed, Chris...
Somebody bought it for me. Must try that excuse myself 😉 BTW, UVC LED's can be used for zapping eproms and such, I made a homebrew device for erasing Psion Organiser memory packs. (Ahh, you mentioned leds later in the vid) 🖖
Actually I have tried that excuse and I’m just collecting it for someone or I’m repairing it for someone all grown thin now with the wife. Thanks for watching and comments. Thanks regards chris
Hope to see you Sunday at 11:00 - sweet dreams
I'll be there, to love and comfort you...
I'll be there, too, with my UV protective sunglasses and factor 30 sunscreen applied. Took me ages to find it among all the windchill factor 50 lotion.
@@oldblokeh all sensible precautions!
@@Codeeze thanks Paul - Bring me up some hot chocolate
Fabulous Video As Always Chris That UV-cure epoxy is The Dogs Ding Dongs Picture This Back in The Day Me Trying To Make a Pcb For a Guitar Phazer I Think It Had About 8 I.C.s I Traced The Circuit On Traceing Paper Stuck a Piece Of White Fablon On The PC Board Then Stuck The Traced Circuit On Top Of The Fablon And With a Sharp Craft Knife Proceded To Cut All The Unwanted Fablon Out Took Me Bloody Hours But When I Etched It With Ferric Cholhride It Dident Turn Out Too Bad Thanks For Uploading P.S. You a Good Friend Of Mr Putrid Chris he he Regards mike
Back in the day I used to draw on the copper using marker pens and had some stick on transfers for the IC pads. Great day and nothing wrong with doing it today if it works. I enjoy keeping these old skills alive makes me feel young. Thanks for watching regards chris
Great tip on the UV eraser, thanks! *Question*: Could you use the UV-cure epoxy to make traces on a PCB? In other words, draw the traces carefully with UV epoxy, expose it to UV, then etch the PCB? That would be useful for a quick-and-dirty PCB project, like a filter or crossover. Not sure how the epoxy would come off, maybe a little heat and a scraper? Great video, love the channel, cheers!!
You could do that but you may as just draw on the PCB using a permanent marker. That’s how I made them before electronics CAD was a thing
Interesting data you have on the old eprom. 🤪
Yes isn’t it. Maybe random corruption
That was interesting, yes i also remember erasing was 10-15 minutes... nice how you bring also so many other facts in a very nice way... thanks!
Hello Tony - Sometimes its nice to do work on simple things but sometimes they end up being quite interresting. Thanks for watching and comments Chris
And they used to panic about taking the label off the top of an EPROM for a few seconds, lol.
I used to panic back in the day LOL
UV Cement, I knew that industry was using UV activated glue's and cements after seeing this video I think I'll give it a try though. I seem to have horrible luck gluing parts together.
I think it’s ok in terms of strength the main bonus being the very fast curing time. Thanks for watching and comments regards chris
Lovely, I would have loved to get that exposure unit for making PCBs a dozen years ago… I actually used a dual standard fluorescent light, as they give out UV too, they rely on the polycarbonate diffuser to block the UV.
Hopefully have ago making some PCBs again I have some projects planned in the future
I’ve had bad EPROMs in one of my Datron’s
It's the little things...
How about a mercury vapour discharge lamp and break off the outer bulb to just leave the quartz element exposed without the fluorescent coating?
I guess it’s what you have to hand. But those Mercury lamps do have a several peaks and one is at the correct frequency for UVC erasing. Thanks for watching and comments regards Chris
They used to be so expensive - I still have one, much used along with all my other PCB making kit. Mind you, you can buy 5 ready made boards from China for less than a plain unworked board!
Your quite right about the cost of making the boards its much easier to just buy them from china and let them have the trouble. Still sometimes it is nice to just do the craft things.
@@allthegearnoidea6752 That Mega site looks like a good toy shop :)
I've got a UV eprom eraser and my tube is clear and it has a blue glow inside, but
mine has a drawer and it won't work till it's closed. Also it has a built in timer.
Yes I had similar units back in the day when I wrote software for microcontrollers. Unfortinately it all went in a skip once EEProms became available. I dont miss the waiting time.
lol i think the data is interesting to run
I wonder if your Eprom was meant for the Russian market... if so, I hope they have UV erasers available before plugging them into someone's device or pacemaker or such...
Well it was chosen completely at random. I actually have no issues with the Russians, lovely warm hearted people in my experience but I do have an issue with Putin.
Of course. I understand completely and I share your opinion about Poutine. I was actually just being ironic, you know.
Although it is kinda funny to imagine such an Eprom would end up in one of his personal devices.
Years ago I had the idea of examining random ROMs just for the fun of discovering obscure or mysterious code or information left behind by some programmer. I might still have a go at it if I end up buying one of those little ROM reading tools you showed
Of course you can change unprogrammed bits to programmed ones, without erasing the eprom :)) by just flashing over it...
I was OK until you got that gadget off your wife, totally lost now. Further info; you only have one of a pair of EPROMs, you have the even EPROM called Putin. There is an odd EPROM called Boris. Both have essentially the same data.
Yes I also use PCBway and some others. But occasionally nice to roll my own
@@allthegearnoidea6752 Sorry I've edited my comment and made your reply look mental...sorry about that.
@@radio-ged4626 no worries