>£50 Sterilisation Robot - Page 1
Forum section: electronics / projects

author: rickey1990
author_rank: Regular Contributor
timestamp: August 06, 2015, 12:14:20 am
content: Recently iv been putting afew projects together to use as examples for a new charity id like to set up, building and designing things that are made cheaply as a non profit orginisation. Alot of the stuff is made from old stock, returns companies cant sell, products made a couple of mm to big or short. i intend to exibit these at different events.The picture above shows an example of whats out there in UV Sterilisation, prices range from $6000 to $16,000 , i fort "thats alot" so i did some research, because non of these companies provide any technical details on the power output on these devices, so iv been zooming into some photos, some with image inlarging software. the device above uses 16 UV-C Lamps at a lenght of 35inchs, the news has coined it as the "GERMINATOR", looks great until you realise the Lamps are 18.4 watts each (Total 294.4watts), which turns the subject to why use so many low wattage bulbs?, would the customer think "wow" im getting all this for my money, 16 bulbs :0, thats alot more than other one's. Also after the 8000 hours of bulb life, you have the privilage of paying for 16 more. And listening to the video, theres a faint hint of ringing. which i hope is not them using cheap magnetic choke ballasts (for driving the lights) instead of the newer electronic ballasts.All these products state the same sort of thing, how it will save lifes, so id like with this project and others to hopefully bring down the current price on life.My project, uses 4 X 4 foot 75watt lamps (300watts), 4 75watt choke ballasts (i can use them because my project cost me just under £50) A arduino to control the sensor, to cut off the lights if it detects a human's presence.The main frame is just scrap wood and HIPs plastic, as it just a prototype. the body will be wrapped in silver mylar as its cheap, 50p a peace, light weight and reflective, iv chosen gold mylar for the base because things in gold mylar do look awesomeWoodern frame, still abit of work to do on it, wating for the first bit to dry. Also down the middle will be a pipe,tempted to hook a shop vac attachment to the base and put a cheap air filter on top.

author: helius
author_rank: Super Contributor
timestamp: August 06, 2015, 12:58:04 am
content: Am I the only one who finds that picture frightening?How do you reliably detect human "presence"? By smell?The PIR detector you showed will only sense moving warm objects.

author: mikerj
author_rank: Super Contributor
timestamp: August 06, 2015, 01:11:26 pm
content: Quote from: rickey1990 on August 06, 2015, 12:14:20 amAre Apple making military buildings now?

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: August 06, 2015, 01:55:33 pm
content: Sorry if this is a dumb question, but WTF is the device for? And who are the chaps/terrorists/SAS in the foil ponchos?Regards, BT

author: Deathwish
author_rank: Unknown
timestamp: August 06, 2015, 01:57:15 pm
content: Quote from: BurningTantalum on August 06, 2015, 01:55:33 pmAndy McGrab

author: DmitryL
author_rank: Regular Contributor
timestamp: August 06, 2015, 02:12:00 pm
content: Quote from: BurningTantalum on August 06, 2015, 01:55:33 pmThey are specimen to be sterilized, apparently

author: daedalus
author_rank: Regular Contributor
timestamp: August 06, 2015, 03:04:25 pm
content: The fallacy in your analysis is the idea that the cost of this item comes from its components. This is a sterilization system for hospitals, most of the product development costs will be getting it certified, and doing intensive in situ testing in hospitals to prove it is effective. Testing something like this in a hospital could easily set you back 0.5mil+/year, and eat a year or two.The sales price will also include some pretty high cost of sales (hospitals take a lot of hand holding to buy anything), around 50% commission to the distributor, support costs etc. The cost of the components is only a tiny fraction of the actual cost of delivering this.There are for example 168 trusts in UK, if each bought 10 of these units, then you are still looking to cover a development budget of a couple mil on a couple thousand unit sales.Whilst you can bodge this together at home for a fraction of the cost, you are ultimately building something you have no personal use for, and the kinds of people who might use something like this (hospitals) will never touch it because its unproven / not sold in a compatible way, and should you find the funds to prove it works and set up the kind of sales team you need to sell to nhs, you are then in the same price bracket as the competition.Also the reason they use lots of little tubes is not "to look expensive", it is to provide lots of redundant point sources of light to reduce shadowing / overhang effects (which would leave contaminated areas). It also has the side effect of providing some redundancy to bulb failure during decontamination.

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: August 07, 2015, 07:50:54 am
content: Ah ! Thank you Daedalus for indirectly answering my question- I assume that its function is to sterilise a room or large volume, and that it would be placed in the middle of said room and left alone for a period to do its duty.I must admit to not having any inkling that such a device existed and was used thus.Regards, BT.

author: Kalvin
author_rank: Super Contributor
timestamp: August 07, 2015, 08:08:45 am
content: IMHO, placing the tubes in circular pattern will create better UV-light intensity distribution compared to the 4 UV-light tubes.

author: Kalvin
author_rank: Super Contributor
timestamp: August 07, 2015, 08:12:40 am
content: How about using UV-leds? They should last longer, be more robust, require less power, require less space, it is easy to create sterilization containers in different shapes and sizes, doesn't require ballasts, can be powered from 12VDC. etc. ...

author: jwm_
author_rank: Frequent Contributor
timestamp: August 07, 2015, 08:18:11 am
content: Every time I go for a piece of bread and find it moldy, I think i should dig an x-ray tube out of my junk bin and throw it into a heavily shielded breadbox such that it turns on when the lid is closed. Would do a much better job than some UV LEDs at sterilization.

author: fcb
author_rank: Super Contributor
timestamp: August 07, 2015, 08:25:42 am
content: Quote from: Kalvin on August 07, 2015, 08:08:45 amIf saving money is a big deal, why not just have one tube and spin the robot - slower, sure - but cheaper.

author: Kalvin
author_rank: Super Contributor
timestamp: August 07, 2015, 08:59:19 am
content: Quote from: fcb on August 07, 2015, 08:25:42 amTotal UV-light exposure dose per area needs to be equal in both cases. I would guess that a higher intensity UV-tube would be required in the spinning model. And of course, mechanical system has its own drawbacks.

author: LukeW
author_rank: Frequent Contributor
timestamp: August 09, 2015, 03:16:48 pm
content: Quote from: Kalvin on August 07, 2015, 08:12:40 amUV LEDs only produce relatively long wavelength "blacklight", not the hard UV (shorter wavelength) required for sterilization.

author: Kalvin
author_rank: Super Contributor
timestamp: August 09, 2015, 05:23:50 pm
content: Quote from: LukeW on August 09, 2015, 03:16:48 pmYou are right. However, there are UV-C leds available with the "deep UV" ~ 250nm wavelength. I have no info about the price and output power. There are quite a few UV-C leds available in Alibaba, but most of then look quite small.

author: Paul Moir
author_rank: Frequent Contributor
timestamp: August 10, 2015, 12:34:41 am
content: Two things occur to me:1: You'll be surprised by how much the output of those germicidal bulbs depends on temperature. Plan to cool them with a fan to increase output.2: Are you sure the gold mylar will reflect at 253nm? I'd bet the aluminized stuff will based on how well aluminium reflects way up there, but I would certainly test first before committing to the design.3: Many plastics break down pretty rapidly under that kind of UV.