Inside a proper optical smoke detector (Status)
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- เผยแพร่เมื่อ 8 ธ.ค. 2021
- A look inside a photoelectric smoke detector that uses infrared light to detect an increasing smoke level in a room.
I strongly recommend buying smoke detectors from local outlets like supermarkets, as that will guarantee a device that is compliant with your countries regulations.
There are very poor quality smoke detectors on eBay that use a cheap microcontroller to give basic functionality (if they even work at all) but for just a little more you can get real branded units.
I think this one either came from Poundland or the local Shoprite (Isle of Man) where they cost around £5.
This one uses a dedicated chip that is designed to self test in several ways, and also reduce the risk of false alarms by differentiating between specs of dust passing through the sensor and actual smoke.
The sounder is driven by a dedicated section of the chip with proper feedback to ensure it is loud by resonating at its maximum efficiency.
The shielded infrared smoke detection chamber has an emitter and sensor positioned to avoid direct light coupling. But the circuit does test the emitter and detector by looking for the low level coupling that occurs by reflection.
I recommend replacing smoke detectors at least every ten years. They can accumulate dust and reduce in sensitivity over time. They cost so little that it can be considered preventative maintenance. If you buy the same type it may fit on the existing base for an easy swap.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
www.bigclive.com/coffee.htm
This also keeps the channel independent of TH-cam's advertising algorithms allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators - วิทยาศาสตร์และเทคโนโลยี
Most entertaining. I can tell that you spent quite a long time determining how it works with this one. I Appreciate the time and effort that you put in Clive.
Very old design, the IC itself dates back to your very early CMOS process, which was one of the first uses for low power CMOS in consumer electronics, as the battery lifetime with the CMOS IC was equal to shelf life on them. That IC has been around since the 1970's, originally from RCA, but second sourced from many other manufacturers as well.
The RCA datasheet for this IC goes into much more detail, including the photos of the actual die itself.
It is good to keep a proven design instead of changing the design just because and then have to work out problems.
@@marka1986 True in some cases. However, it's always worth it to ask if we can do better. For example, modern ICs can work down to 1V or less. So, a detector could run even longer. Following that, 9V batteries aren't as common as AAs, so lower voltage allows that as well. That's mostly not a re-design of the detector as updating the chip to more modern manufacturing standards.
Then we have all the cool / mandated things. For example, in many places new houses must have smoke detectors which are linked. That means if one goes off, they all do. It's even easy to find ones that go with a wireless security system.
@@arthurmoore9488 or just stick a lithium 9v in when you need to replace the battery
@@arthurmoore9488 Then someone decides it's "cool" to make a wi-fi connected smart home iSmokeDetector that stops working if it hasn't had its daily firmware update...
5:17 These "dark rooms" attracts also small bugs, i have experienced it a few times that one of my smoke detectors starts whining for no reason, while the battery was new.
After removing them from the ceiling they stay quiet for a while, sometimes they start again after a short periode of time.
The last time i suspected that it was a bug, i placed the smoke detector inside a zip lock bag for a half hour, and the little bug left the crime scene and was visible in the bag 🤣
I've seen that some smoke detectors have some sort of a net around the chamber whilst other don't.
This is where radioactive smoke detectors really come into their own.
The design of the ir lamp and ir detector chamber was very neat, allowing smoke to enter but reducing the chance of outside light to virtually nill, even the screening from the ir lamp was in the same style as the outer ring.
Very informative once again Clive, thank you.
I recently had smoke alarm give regular false alarms, and when I opened it found out a small spider had moved into the detection chamber. After evicting the spider and cleaning the cobs out it worked fine again. nice teardown :)
That's funny
Yep. I've had spiders run out a few times after false alarms and blowing it out with canned air.
oh....OH MY GOD I GOTTA CLEAR OUT MY SMOKE DETECTORS, THAT EXPLAINS *EVERYTHING*
I don’t have a lot of electrical engineering knowledge but I feel most of what I have comes from you! As a kid I loved to disassemble old telephones and such just to see what was in it and these video’s scratch a nostalgic itch for which I want to say thanks!
The detector diode is reverse biased and only draws current when illuminated. I think the strobe connection is grounded during the test period so the sensitivity pot works. If it is open (transistor off) the remainder of the the time there will be no current trough the sensitivity adjust resistors. This will conserve battery life as you stated. I think the detector amplifier is a transimpedance amplifier with the input node near V+.. C1, C2, and R14 are most likely loop stability compensation.
The most interesting part to me was about the three terminal piezoelectric sounder and feedback driver. I had never looked in detail at one of those. I learned something new from this video. Thank you.
I love your reverse engineering of the seemingly most basic electronics...I find them so interesting and entertaining and often feel like I'm learning stuff! But don't tell anybody else okay? 😂👍🏽. Keep em coming!
There's an issue with having the piezo sounder standalone in one half of the clamshell; in an 'infapower' CO detector i have seen electrolytic corrosion set up between the sounder and the spring loaded contacts.....the alarm knew it had a problem but couldn't alert me to it since it's voice had gone. Just happened to notice the yellow 'fault' light flashing as i was dropping off to sleep, then found the fault. This was after 6 years into it's expected 10 year life, and it wasn't even in a hostile environment. I won't be using any alarms without hard-wired sounders in future.
I have seen the same issue with older cheap smoke alarms. They were laughably quiet or silent during tests despite a full battery. The newer alarms seem to all have soldered wires or corrosion-resistant plated contacts.
... Same happened to the one at my Mom's place back in the days - noticed this odd clicking / buzzing noise, and quickly traced it to the smoke detector, which was in alarm mode for some reason or other, I think the sensor chamber had accumulated dirt inside...
Fascinating to see exactly how the self test works. Thanks for sharing this one Clive.
Some of the modern ones are made around MSP430 microcontrollers rather than that ASSP. The shield is necessary (or at least desirable) because of the small analog voltages in play.
The piezo is glued in because it needs to make an airtight seal - there is a resonant chamber there. In the ones I worked on, the piezo was glued to a polystyrene speaker cone that was itself glued to the end of the cavity.
We have on multiple occasions spiders crawl into the chamber setting them off. My daughter really loves it. Also in my days of theatre work we would have to call our alarm company to have the system put into test if we were running fog or diffusion machines.
Fascinating take-down.
I've never been a fan of optical smoke detectors, due to my experience of them in the cable tunnels in the power station at which I spent most of my career.
There was a mixture of ionisation and optical detectors due to the different smoke particles that could be expected in a fire, but during every harvest season, the thripps (thunderbugs or corn flies) would leave the fields and head straight for the optical sensors putting them into alarm. The only remedy was a massive program of insecticide spray, carried out either by our staff or the fire alarm contractors.
I recently bought a new smoke alarm and thought everything was okay because it regularly blinked it's little LED.
But when I tested it again, after about 2 weeks, it just turned off with a low battery instead of beeping 🤦♂️
I guess this is why many smoke alarms are hard wired now days.
Test regularly.
I don't trust the mains-powered units after having one catch fire.
@@tncorgi92 that’s ironic! Also I remember some murder show long again on which a killer turned of the circuit for the smoke detectors and set the house on fire killing everyone inside. I don’t remember if they took out the batteries leaving no backup or what but It’s stuck out in my mind ever since
If I buy something that is battery powered I throw away the supplied battery and put in a new one from a reputable manufacturer.
@@tncorgi92 you need to buy a - proper - mains powerd one.
Don't buy strictly hard wired smoke alarms .get them with battery back up .they even have them with wireless pairing so they link up together without additional hard wiring .So much variety today with lights without lights combination smoke/co and talking !There are also hight temp and low temp alarms as well .Specific uses .many types
Interesting, just last week I modified one of my smoke detectors (out of pure interest I provided it with a 433MHz transmitter) and it works with an MC145012 chip, which is more or less the same as the MV145011 (exactly the same pin assignment, etc. .). The story with the piezo-beeper and the 3 connections still was a mystery to me ..until I came across your video - thank you very much for that :)
Regardless of that and said with all due respect: I know that you love to deal with all this Chinese-LED-etc-rubbish-junk and to take everything apart down to the last detail - you do it with the highest precision and with skill, but sometimes I would really love to see you dealing with more "serious", useful (and far more interesting) stuff like - for example- this ...just sayin' .)
Even being a fireman for a few years I never knew exactly how these worked. Thanks for sharing!
Thanks Clive, I'm enjoying these videos and your soothing voice while stuck at home with head and muscle aches from my booster vaccine.
2:19 Yes... I personally prefer when components are spiritually glued.🙃 Thanks for the video! Oh, and really good advice too.
The way they use the Schlieren effect to see the particles is also incredibly impressive considering the simple design of the chamber.
Many US states that unit would be illegal to install these days. Most have laws stating any new buildings have to have hardwired units with 10 year sealed battery back-up. So you activate the unit, plug it in and in 10 years it will start chirping to alert you that you need to replace it. Kidde has a list of the laws on their web site for those interested. This is the NY version - Smoke alarms are required in all residential dwellings (single family homes, multifamily homes, hotels, rental properties, dormitories, etc.). Smoke alarms in newly constructed or renovated dwellings are required to be hardwired with a battery back-up, interconnected, and UL-listed. Sales of battery-powered smoke alarms are restricted to alarms with a 10-year sealed battery.
And it's darned annoying when one of those starts chirping. What with years between battery changes, it's hard to recall where the sound might be coming from.
@@tubastuff I just write the install date on them and go get new ones the month before, it's handy though to look at the build date on them in the store and buy the newest ones they have.
@@Blazer02LS It's SOP for a lot of landlords here to replace all smoke alarms in an apartment when a different tenant moves in. I once came across such a box of discarded alarms that all had the 9V lithium 10-year batteries. I left the alarms behind but used the batteries in various applications (garage door opener remote, DMM, etc.) and got several more years of service out of them. The nice thing about lithiums is that the voltage stays pretty constant until end-of-life.
Thanks Clive. Really enjoyed seeing that.
Interesting Stuff!.. I had a rough idea how the optical smoke alarms worked, great to see it explained by the boss 🤩
Nifty. Learnt that non-radioactive smoke detectors exist *and* that they can be set off by little moist bug feet (Love the myriad ways you turn a phrase). A day that you learn something new is a day that hasn't been wasted.
Fascinating! It's interesting to see how this stuff works. Although I have to tell you that I needed some kind of smoke alarm that I could silence remotely as I am a wheelchair user and I had some things that were desirable and things I needed from one. There's slim pickings for smoke detectors that met my requirements.
The only one I found suitable was the Nest Protect Carbon Monoxide and Smoke detector. The main thing of a smoke detector I needed was for it to be a smoke detector, as in not have any "smart" functionality that would affect it's performance as a safety device. These have smart functionality but that is all secondary to it's primary function. The smart functionality if it can't work, it won't not sound the alarm.
The remote "silence" feature is quite good in how it works, it only works via Bluetooth and you have to be in the vicinity of your detector (so you can't silence it from outside, if you could though my partner said that'd make a good murder plot on a CSI xD).
There's two types, mains and battery. The mains one has 3 lithium AA batteries as backup and is hooked into the grid and the battery one has 6 lithium AA batteries. They both have a path finding light at night, but the battery one only comes on when it detects a human. It also reads out in clear English which room has the fire or CO and tells you what to do - Great for kids or people that get easily confused. I also like when you turn the light off at night, if all it's self checks have passed, it will glow green for a second, if not it'll glow amber. It also does a test of everything every month (sounder, batteries, connection, link to the others) and they also link to each other as well.
They're not cheap at about £80 each, but I'm kinda glad there's not a bunch of manufacturers making woefully inadequate safety devices, but being a wheelchair user I can't reach up and silence a traditional alarm, so after much research, I went with the nest protects as they're sensibly designed and pass all appropriate legislation, and owned by Google they're pretty good with warranties and supporting their product.
There's also another 'best effort' feature if you have a Nest Thermostat linked to your boiler. If it detects CO it will try and shutdown the boiler, but whether or not this is effective doesn't matter, you still would have to leave the home, it would just mean the emergency services could enter the property earlier if it was able to shutdown the boiler.
The only ones they carry at the local hardware store now don't have a replaceable battery. It allegedly lasts ten years, then you have to replace the whole thing.
yes, all alarms must have a sealed battery now as per law in Scotland, and must be replaced every 10 years.
You were supposed to replace the whole thing every ten years anyway.
I installed a few infrared laser laser smoke detector in a Temple .the laser shot across the vaulted ceiling ,bounced of a prismatic reflector and back into the unit .it used a visible red laser to help you align the unit ..It worked quite well .No false alarms .Unit came with a bypass key when they would be using incense or indoor fireworks .It was a Chubb Edwards addressable system.basically anything interfering with the beam over a certain period of time would trigger an alarm.Same principles
Neat!
That's called a beam detector
@@FireTech7 yes it is called a beam detector .Love that device !
@@carlubambi5541 I have a beam detector but I have yet to hook it up
@@FireTech7 They work amazing .some models don't have a red Laster to help you aim it .So I use a laser pointer to help line it up .
I saw the video announcement and immediately had vision of “The Mask” with Jim Carrey saying “Smokin’!”
Great tear down thus far Clive!
Also if you want an Australian Smoke detector I can send one over. AMPAC have a detector that gets its loop address from switches on the detector that are actuated by fingers on the base. Which means of you replace a detector in the same base it always gets the same address. Most of the other makers program the address with software or dip switches on the detector. Fire detection loops are quite interesting. Tyco another Australian manufacturer actually provides a lot of technical detail on how their loop works. Voltages, currents and signalling etc.
Absolutely brilliant Clive
Finally understand why these annoying levers are in the battery bay! THANKS!!!
Remember that smoke alarms have a sounder and smoke detectors just detect air contamination and have a seperate device to sound the alarm. I've come across many fire industry people who incorrectly use these terms interchangeably.
My Mum's smoke alarms get tested every Sunday when she makes Bacon Butties.
Very interesting breakdown, thank you professor.
It's good a lot of clever circuitry in it
Good vid BC, I have fitted hundreds of these things in people's houses years ago, I honestly never really knew how they worked. 👍👍👍
Just what I wanted to learn, thanks again sir
The way the face of that sounder looks, looks exactly like my plasma disk
See, now I want to build a gazebo in the style of that smoke detection chamber. All the breeze and none of the sun in the summer?? Sign me up! 👍
I have always wondered how these work.... not I know a bit more on the functions of smoke detectors. Thanks Clive!
Oh I "love" playing the multiple reattaching clips game! Especially on large, cumbersome objects like tower fans 🙄
A great explanation of the circuitry and how a smoke detector works. Plus, the added info about how important it is to keep the dust trap chamber clean. Also, to press the test button on your regular testing day, e.g. Monday... If it is too high for you to reach, then use a long brush shaft or what you can to press the tester button to check the alarm.
Please remember to never cover up or remove a smoke alarm unless it is faulty. Contact your building fire officer and/or handyman. If in doubt about its working condition telephone your local fire station on their non urgent directory number to inspect the alarm.
In the meantime, if you smell smoke, see smoke or the alarm sounds, Get Out & Stay Out. Never go looking for the cause or tackle on your own. Use any anti fire Blankets, Sand Buckets, Fire Hoses or Extinguishers etc to aide your escape. They are best used for that purpose to save your life. Leave the Fire Fighting to the professionals who are qualified to tackle a blaze of any size, small or large.
Got two of mine in the garage for the past 3 years. 8)
The batteries long removed and one of them started chirping for a day like 3 months ago. Was wild. It's quiet again.
I'll reinstall them when I sell the house.
I recently took down fire detectors that had no electronics from an old house I bought to remodel. Very heavy and took me some time to figure out all the gizmos that made it work, when it turned out to be quite simple, yet effective if you were within earshot. I would love to send you one if interested. Ear plugs are a must. You might already be familiar with them. They are quite heavy.
YAY, now can see what is salvageable from old ones.
Had a smoke detector go off recently, probably three years old. Cleaned it with a vacuum, but it gave another false alarm a week later. I then blew it out with compressed air and it's been silent ever since, so I guess it's either repaired or completely buggered up :)
You can test it by burning some toast. They usually have a red test button on them but that just tests the battery and the alarm, it would ring even if the detector was clogged with dust. You really should test it by burning some food, smoke detectors are the most valuable thing in your house because they could save it some day.
This is where the test button comes in I suppose.
Fascinating, as always.
Thank you Clive
Last time I went to buy a battery for a smoke detector, I discovered that a whole new smoke detector of exactly the same style with 9V battery included was around the cost of a premium brand 9V battery (about $5). I replaced the whole thing and threw the old one in the electronic scraps bin.
I wonder if those screws with tape over them are just to show if you happened to tamper with the alarm.
So many of the tv news reports about fires mention smoke detetors that weren't working properly, or which didn't have batteries installed. One solution to this is the newer units that have come out that instead of the typical 9V battery has a built-in lithium cell of some sort. Designed to last "the life of the device" and then the whole thing gets replaced. I know of at least one locale where these are mandatory for rental properties.
感謝你拆偵煙式住宅用火災警報器研究 非常有用
別客氣。
Thanks BigClive I have just tested and replaced the battery of my smoke detectors
Clive, Great video as usual - you always have the best reviews. Concerning this circuit and the MC145011 chip and supporting circuit, it would be interesting and possibly useful to hack the circuit and make a real air and particle detector. You could take the signal off from the IR receiver and count the number of particles as air is driven through a small chamber. This could be so much easier to deploy than the multi-thousand dollar instruments currently used to detect air pollution and contaminants suspended in the air. What do you think of this approach?
Reminds me that I need to replace mine. Thanks for this
They usually have a manufacturing date, a spot for an installation date, and an expiration date on the label of most smoke detectors. All of mine were expired after 10 years.
The expiration mainly applies to ionization equipped detectors. This one doesn't have it at all.
@@Orxenhorf I'm assuming their expiration is to do with the half-life of the isotope they use?
@@Orxenhorf not necessarily the newer ones at least in the US are now required to be hard wired to power and they also have a built in battery that is not replaceable. So the date is also to indicate end of life for the battery.
@@krashd Yes
@@Robert-Wilson Hardwired yes, but the batteries vary between model and the non-crappy ones will last longer than that with hardly ever using battery power and constantly being able to trickle charge.
I have installed about 50 ei electronics ei650 smoke alarms in my life. They are excellently made and have a 10 year battery. The cost is perfectly reasonable since you pay for 10 years and you really are getting much better quality than with your average smoke alarm. They can also transmit diagnostic data to a smartphone via the beeper.
There's so much going on. Cheers for the tear down and explanation.
I would like to see a tear down of the singing bear you showed on the live stream a couple of weeks ago. :)
Worth watching just for the spider impersonation alone 🕷️
WIth the new regs in Scotland the costs are increased significantly. Whilst looking for a new system to meet the regs I noticed that you could get either mains powered interlinked detectors or battery powered linked detectors. but they are no compatible. In my house the main living accommodation is on the first floor meaning it would have been easy to install mains powered detector but down stairs would have meant damaging ceilings and the need to fully decorate etc. Its a shame that there isn't a hybrid system that allows both battery and mains powered devices to be interlinked. That said the FireAngel detectors I have installed work great.
Aico Ei650RF battery smoke alarms will interoperate with their main powered Ei3016 series provided you fit at least one of the 3000 series with a SmartLINK module. I fitted a couple of battery units to complete my setup as the ceilings were going to be difficult to route mains across.
@@davefiddes I was told they were not compliant with the Scottish regs because the battery was not sealed and guaranteed for a minimum of 10 years
@C P detectors designated as D1 (mains-powered, tamper-proof backup battery), D2 (mains-powered, user-replaceable backup battery) and F1 (tamper-proof battery only) are permissive under the new Scottish standards.
@C P these three grades can be interlinked either entirely wirelessly, entirely hard-wired, or a mix of both.
Aico have released an updated PDF outlining the combinations of their product line to suit our new legislation.
Search "Aico Scottish legislation" and scroll down to 'view the brochure' near the bottom of the page (not the pocket sized guide at the top).
@@_Steven_S Thanks Steven, I am sure this info will be useful to others, but it's too late for me. I have already installed the FireAngel battery sensors with remote and they are working really well, but we will see what they are like in 5-10 years.
Great video, as always! Would be great if you would do one on the various bms boards available on Aliexpress, such as the HW-391 bms. I've seen them used in upgrading power tool batteries from NiMH to Li-ion, and I wonder how reliable they are. Thanks for all the work you put into your videos.
Rare to see optical smoke detectors today. Most are ionization.
I have a 1970s AC-Powered _Vanguard 'Smokesonic'_ which uses an incandescent bulb as the light source.
Strange looking gold perforated metal "bell gong" style device.
They all seem to be going optical here. Probably because they're cheaper to make and don't have "dangerous" radiation in them.
@@bigclivedotcom Also possibly because they use Americium instead of Britium. ;)
Here in Massachusetts, either photoelectric or photoelectric-ionization combination smoke detectors are required by code. Photoelectric detectors are said to be more effective in detecting smoldering fires, while ionization detectors are said to be more effective in detecting flaming fires. Smoldering fires are said to cause more deaths.
😀 - vintage
In the Fire Alarm industry it's the other way around. Ionization smoke Detectors are the rarity and they're usually 20+ years old.
Nice demonstration you made here, so now we need to look inside one of these radioactive ones which charges the smoke particles when the radiation strikes them and generates a voltage on the sensor, nah I know you already know this and I value your safety. keep up the good work!
The Spider comment is interesting Clive, the one in our bedroom went off at 6:30 am the other morning for a few seconds, not a beep from it since ... maybe I had a wayward bug too !
Informative and interesting and maybe saving lives one video at a time. ⚡️⚡️⚡️🍻
The periodic Illuminate-Check cycle and rechecks looking for an increase in reflectivity will also avoid false trips from things like strobes that are bright enough to get into the chamber.
Going deeper with Clive.
Good channel name.
Awesome big Clive
8:02 The cost difference not negligible, it is potentially your life and/or that of your family. Thanks as always great tear down.
My personal favorite is the Fireangel Angeleye smoke detector. It just screams quality, at a decent price. Might wanna take a look at them, Clive.
timely...i just pulled one apart the other night as it started going off at 3am for no reason whatsoever (it was only tested by licenced electrician/installer like a month ago..SMH)...this one has a pack of 3 cr2023 button cells on a little board with some passives (rechargeable) and its wired into the light circuit, and to a 2nd alarm in another room... it also didnt have a peizo, it has an actual speaker like from an old phone handset...
i didnt pull the chamber apart, but it looked very much the same from the outside
i put it all back together and put it back in place, did a test n it worked, and havent had an issue with it since.. i think the batteries where not charging correctly as the voltage was less that 1v (altho it was still loud as hell n woke me up...twice!)..im thinking the electrician may not have placed it back on its holder correctly and the mains connector pins werent making a good connection or somthing
Learned some, left happy ;)
Seems well designed, and this one's not radioactive! I personally find status products to be quite good.
2:36 I was really hoping for the 'we must go deeper' reference :D
Now we need a smoke detector testing set up next to the 2 fork cooking chamber. How many watts does a sausage need to activate a smoke alarm?
I find it fascinating that hanging a few 10 pound devices on the ceiling here and there will safe your life one day.
Just how it detects smoke is soo cheap just a piece of plastic and 2 diodes, yet it's soo reliable.
We here in New York USA now have to buy smoke detectors with built in batters. No more replacing the battery. Just thru the unit away.
Regularly replacing them seems like a good idea. Though the really good combined smoke and heat detectors are quite a more expensive and if you want them in a non-fugly design with useful features like low volume testing (and yes, it's important to make sure they actually do work and can make a sound) or mesh networking then they're *way* more expensive than the regular cheap ones. Mine (without networking!) cost around 45€ a pop and I have 9 of them in my home...
That is expensive. I suppose its only €40.50 annually over ten years. Do they sell them at a discount if you buy them in sets of 3, 5 or 10? If they're the 10 year total lifespan ones that you recycle after is there a buyback when recycling? I would imagine they just test old ones, replace the casing, smoke detection chamber, heat detector, battery and then sell them as "new" after you recycle them.
Awesome video might I suggest a teardown of an ionization smoke detector
My old boss thought he had a gheko in his light fitting. Took about a week of cool winter nights to work out it was the occasional low battery chirp of the smoke alarm as the battery finally reached ambient temperatureand lowest voltage late at night.
Next year all rentals in Queensland Australia require hard wired or wireless interconnected smoke alarms, so if one goes off the rest will. Thanks to lithium cells, the wireless ones have a 10 year battery life.
That optical detector is just brilliant except for the occasional bug detection.
From early next year properties in Scotland must have multiple "interlinked" smoke alarms, either wired or battery. For my flat (apartment), I must have a smoke detector in the main living room and one in the hallway, plus a heat alarm in the kitchen. The 3 alarms are about 2m apart. If you have a house you'd require 4 alarms. If you have gas you also need a CO detector. At £50 each somebody is making a large profit on this. (Scottish Parly response to Grenfell Tower fire)
@@ziplockk Canadian here... You just got me to google Scottish politics to figure out what you meant by fishwife and her fishy friends. I'm always learning new stuff from Clive's videos. :-)
@@ziplockk (I also googled fishwife for good measure and learned another thing.)
Similar situation here. 83m² 2 bed flat on a single level. 2 opticals, a heat and a CO.... all sighted within 2 meters of each other. £170 in "parts" at today's prices.
The system in the communal areas.... completely isolated from each of the 8 flats 🤷
Good advice about changing them out every ten years. I'm still using ones that were installed twenty years ago which is probably a really bad idea...
You may have the old radioactive ones yet.
The combined carbon monoxide-smoke detectors have a shorter replacement interval, I believe because of the CO detector life.
As always, an excellent and fascinating analysis, Clive. Perhaps proper conformal coating would be more suitable to coat the sensitive receiver electronics. Though, it is still altering it as you say. People must bear in mind, the real cost difference between a correctly engineered smoke detector and a fake, is your life. Don't skimp on it.
I starting to think Clive might be the reason we are having supply chain issues. His Fleabay shopping sprees surely have to take up a few ships that would congest even the largest of ports... Thanks for the great content.
Would like to see a breakdown of an aico Ei 3028 multi sensor and Ei3024 heat and CO.
Good Friday morning to you sir
Nice a video on smoke detector as ever going to be interesting
thanks Clive. RLTW!!
Hey, I love your explanations. Can you do a teardown of an in grund invisible dog fence, and how viable is to extend its range (cable range) I've seen them in aliexpress for around 30 quid
I use both ionizing and optical smoke detectors, one is good for flash fires and the other for smouldering fires. To clean the optical ones I use compressed air after vacuuming. My problem is getting to one that is at the top of a 20 foot ceiling, short of erecting scaffolds in the living room I can't get to it. Very interesting on the design and power saving choices made.
Why not a 20 foot ladder?, the maintenance guy at the old work used one to service lights in the front lobby. These usually have a wider base to not tip over.
I opend some smoke detectors produced between 2001 and 2020 (sold in Germany); all chips: MC145012, A5358 and CS2105GO-M12 are fully pin-compatible and use the exact same circuitry
...and so to the pinout of this KD-5810
Thank you, very interesting and entertaining indeed! A problem I have with smoke detectors is that the low battery warning always occurs in the middle of a cold winter night. Our room temperature (thermostat) goes lower at night which causes the detector battery voltage to sag enough to trigger the low battery beep. I easily sleep through some random beeps, but unfortunately my other half does not and forces me upp to resolve it at once.
I tried NiMh batteries that I charged every year but they didn’t last much longer than a good disposable battery. Maybe a smoke detector that runs on two (rechargeable) AA batteries with low self discharge could work longer/better?
It's a bit of an investment effort in terms of wiring, but if you can, buy and fit a mains-powered detector. They won't beep in the middle of the night because of low temperature or low battery effects.
acamperfull, its the law in australia to use alkaline batteries in detectors. there is a common sense reason for that. they dont die suddenly.
@@SH-vv7zq Oh yes they will. Always at 0200. I won't say due to temperature, just the battery having no useful life left. At this point, I just swap them once a year, regardless. It's like one fails then a few days later another... always middle of the bloody night and not necessarily cold at all (though temperature could affect battery performance that isn't the case with mine.) So... scheduled change outs once a year makes my sleeping much easier.
I'd like to place two of the ones I ripped out back up if it weren't for my shower setting them off. Ain't nobody got time for that.
I must reiterate what Clive mentioned. There are some things you don't try to save money on and smoke detectors are among them. I still like the old school ionization base detectors with Americanium inside. They seem to False alarm less, but they are hard to find now.
Interesting. The alarms we use in Canada have a silicon detector and like .001 microcuries of americium to detect smoke instead of the photo detector.
Nice one BC - another T.U.T.Y. (Thumbs-Up, Thank You). I'd like to change of Angle of Attack here for a moment (yes, I LOVE my aviation) if I may: - over the years I've been asked the same question by several folks (including family members, friends & neighbours) - "Why do I have 12 smoke detectors and 12 multi-purpose extinguishers in the house, along with anchored escape ropes in every room upstairs (plus an analogue X-Ray machine, sorry, hammer)?, Simple: 5 years fixing and MacGyvering things in I.T. years ago (plus my Dads advice when we were growing up - a very wise man) thought me the following: Firmware fails, Hardware fails, Software fails, Batteries die, plus even if the one (ONE) detector goes off downstairs in the middle of the night we probably won't hear it (until it's possibly too late) - I've seen far to many news reports while growing up concerning kids dying upstairs after a fire broke out. I reckon(ed) it's because no-one considered it likely, therefore never had a plan! When my two nippers were growing up (they're both adults now) I drilled it into their heads "If you think there's a fire, break the window, put a quilt over the bottom bit (to help negate broken glass), use the (knotted) rope to get out, alert the neighbours, call it in. If you're wrong, I'll repair/have the window(s) fixed myself). Thankfully never had to use the plan, because prevention is better than cure. I also have motion-detecting LED lights at every fire point (i.e. extinguisher). Plus a double-up at my work bench in the kitchen-bit.
I know, I might appear to be a bit of an old woman with this but hey - better being an OLD woman than a young, dead idiot. My routine is to check/test everything on the 28th. of every month (simply because February typically has 28 days, so I won't miss one). Just saying'. I hope what I say here may be helpful/of use. Thank you again, Sir.
i made an electronic tuner sensor from the piezo crystal, good for acoustic guitar, clamped on from a capo. no clip on tuners back in the day. piezo good for el cheapo pickup taped to an acoustic guitar too. yes we live and learn dont we?
I had a few false alarms with cheaper smoke detectors and at some point got fed up and bought rather expensive EI Electronics ones. These are great, 10 years claimed battery life (around 6 years old now and tests fine still) and seem to be really well made (nice double sided PCB with good soldering quality). Not made in China, too.
Clive is always interesting
Thanks for another great video. I wonder if such detectors can be used to detect vaping?
Yes. Vaping fog will trigger them.
Since it a safe device, the three connections in the piezo maybe are used to periodically test if the speak is working using some inaudible signal.
I don't think it tests the sounder except when you manually press the test button.
I have a GMRS radio antenna in the attic above one of my detectors. When I transmit at 15 watts the detector chirps.
i've had mine for 7 years, maybe time to look into a new one