Simplest dusk sensor yet, with nice case for projects

While placing an order for a PIR sensor from a prominent UK supplier I added this dusk sensor in because it looked very "eBay".
It turns out that it may not be ideal for its intended application, but it would make an excellent case for mounting outdoor electronics. Light, temperature and humidity sensors come to mind, but it could also house a USB WiFi dongle or other active antenna for connections between buildings.
An interesting possibility would be to 3D print custom base inserts for specific applications.
I have a few reservations about its original purpose. The relay switching is not a precise digital event, so it depends on the relay maintaining contact pressure with falling coil current, until it drops out. It may be that it does decisively break the circuit when used like that. Something that is important with inductive loads to minimise arcing.
The other oddity is its use of single insulated cores with no obvious way to cover them. In the case of general maintenance operatives there's a risk that if they get handed something like this to install they will just assume that exposed wires are OK and fit it. That would pose the risk of accelerated UV degradation in addition to the lack of the double insulation required for cables outwith an enclosure.
One scenario this might find use is where it's mounted within a clear fronted electrical enclosure with something like an LED power supply, but that would affect its light detecting ability, and clear front enclosures generally cost more than standard ones, meaning it could be cheaper to use a proper external sensor with a plain enclosure.
The use inside a clear lid enclosure could have advantages in a factory assembled box with everything pre-wired inside though.
I'd say this product is more valuable for its case than its circuitry. Let me know what you think in the comments area.
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 KZbin's advertising algorithms allowing it to be a bit more dangerous and naughty.

[@NvTwist]

“Watch your eyes, the light is coming back” 😌 Considers others at all times, quality person & content.

[@mikebarrett2621]

Does not vote Conservative (Republican in US)?

[@NvTwist]

@@mikebarrett2621 A truly egotistic observation to steer attention to ones self, did my comment showing praise & appreciation for another person trigger waves inside your shallow mind.

[@Dust76tr]

And he zooms in for those of us watching on mobile so we stand a chance of being able to see it too

[@NvTwist]

@@Dust76tr 💯

[@erikhendrych190]

Instructions unclear. Eyballs twisted into torroids.

[@CollectiveSoftware]

LDR, transistor, and cap for time delay... this is right out of a classic era kids' electronics kit

[@vychan3708]

Precisely!

[@bigclivedotcom]

It did make me think of a beginner magazine project.

[@bigclivedotcom]

Maybe I'll stick a thermistor in and turn it into a matching thermostat.

[@ThePiGuy24]

@@bigclivedotcom Or just stick a few resistors across the output and turn it into a dusk activated party popper :p

[@zindi1138]

Hence the price

[@tottaka]

the thumbnail looks like a Styrofoam cup with some wires glued on it lol

[@drasco61084]

I thought this too. Thought it was going to be an electronic cup on a string telephone contraption.

[@mattelder1971]

The 8 second delay is probably to keep things like headlights from passing traffic from accidentally triggering it.

[@WarpRadio]

You almost guessed it.. its actually cause of LIGHTENING FLASHES -don't want lightening to cause the lights to flicker on and off esp HID fixtures! :)

[@mattelder1971]

@@WarpRadio Well, I did say "things like". I'm sure there are several possible sources of random lights, and that delay would counteract most of them.

[@WarpRadio]

@@mattelder1971 oh yeah! to be sure.. though usually, those things are mounted up high away from other (usual) sources of light.. AND, I have seen lightening STILL trigger them just the same.. thanks for the reply! :)

[@MrDaniyalAh]

It is there to act as hesterisis. When the light level is just equal to the threshold value then it migh switch between the two states rapidly which we don't want

[@alunjones3860]

@@MrDaniyalAh The capacitor and resistor won't provide any hysteresis. The relay will do that. The voltage threshold to turn a relay on is always higher, than that when it turns off.

[@raymondmucklow3793]

Start days tomorrow, I get to watch Clive before bed, good way to unwind relax. Cheers.

[@HighestRank]

“Qualified electrician installer”: ‘handing off the liability buck’.

[@Karreth]

I particularly like how it's marked as being double insulated.

[@Mattja1]

It's pretty hilarious what those marks are found on sometimes.

[@pear7777]

But it is, both the wires are insulated

[@bradgardam1343]

Double insulated means it doesn't need to be earthed

[@BritishBoy1971]

I know very little about electronics Clive, but your calming voice and method of description in all aspects of your videos, especially your reverse engineering, is superb (even for a novice like me to grasp, to understand and get the gist of what's going on). *Your videos are a great stress reliever, believe me, thank you! 🙂👍

[@michaelmiguelsanchez]

I initially read the title as 'Simplest duck sensor yet...'

[@HeimoVN]

I read dust instead of dusk

[@deedeekay1642]

@@HeimoVN still at 7 mins. into the video, i thought it was DUST! untill I seen your comment!

[@asrcav8r]

I had the Radio Shack 200 project electronics kit and I remember the light sensor experiments. Great, now I feel old...

[@crispy_otter]

I had the Philips Electronics kit for Christmas when I was a kid, with an 'Automatic Night Light' circuit (my fav circuit - it even came with a green cover for the 6V bulb!) ..imagine how old I feel, that was around 1971 🤣

[@erikdenhouter]

@@crispy_otter I had the same sort of EE kit, but I remember that there was no relay involved. A relay needs to switch fast enough to avoid burning in of the contacts, and that is a weak floor in the above design.

[@stevenverhaegen8729]

@@crispy_otter my favourite was the superregenerative receiver, that made a fine air band receiver 😁

[@r1273m]

That would be OK in my loft to provide an external warning of when I leave the lights on up there.

[@keithmaddox1469]

Hi Clive :) Another fun video. Hope you have a great holiday. Don't shock yourself too much :)

[@simoncee9011]

Thank you Clive, interesting as ever.

[@ATMAtim]

I too would have put my money on there being a 555 driving the relay. This configuration is nearly more simple than a 555 circuit. Very interesting piece of hardware. Thanks for taking it apart.

[@Subgunman]

Bought the same item in Greece for 2.60€. I mounted this on a piece of PVC pipe that I sealed with a cap on the bottom. The top of the pipe needed a few turns of cheap electrical tape to get a tight fit. Its been working now for five years with no issues.

[@eebaker699]

Great video as always. I just noticed the Hopi doesn't strobe with the lights out. 😁

[@NeverMetTheGuy]

This is incredibly interesting. Does anyone else ever wonder what's happened along our life's journeys to make us so interested in this stuff?

[@ZAPATTUBE]

A thirst for knowledge.

[@spagamoto]

That Hopi in the darkened room has some pleasing Apollo DSKY vibes.

[@TheEPROM9]

Use to find LDR's in everything back in the day. Photo diodes & transistors were just of fancy electronics.

[@peterjameson321]

Quite right, TheEPROM9. The nice thing about CdS LDRs is that they're not only as tuff as old boots but they're bidirectional too and can be used on AC. In fact, when I was a boy (I couldn't resist saying that!) all this type of unit contained was an LDR and an hot-wire relay. There were no semiconductors at all. The hot-wire relay provided a bit of hysteresis.

[@oblitum]

this weekend i bought a similar one by amazon for a 24v solar street light project. great!

[@thecorbies]

Hi BigClive. A quick search of 'tutorial' on your back catalogue revealed nowt, but just so that you know, (you almost certainly already do), you have an amazing voice to listen to. Perfect for online tutorials. Now there's an idea! Have you ever though about doing online tutorials for beginners? I suppose it might be a bit tedious for you, but I for one would enrol on one of your courses I'm sure. I'm an electro-mechanical engineer, but somehow I always felt like I missed out on the whole semi-conductor age. Would love , love LOVE to know more than I do especially if you're doing the tutoring. Regards Mark in the UK

[@irish-medi-weed-grower5240]

I remember a time in my distant youth when (3:58) ' fingering about ' , had totally different connotations .

[@kimasim1]

Thanks for your intelligent yet humorous opening

[@28YorkshireRose12]

You have me thinking now, Clive. I have a "Zodion" style, and I emphasize the word 'style' which I bought on-line, and which failed about six months later. It came in box labelled up as "Newlec". I naively took it at face value, and installed it, and was duly disappointed when it failed. On attempting to remove it from the Zodion socket, the opaque dome fell off in my hand! Once down from the ladder, it was clear that this thing was a fake, and a poor fake at that! Under the lid, there was the capacitive dropper, a very sick looking resistor, what appeared to be an LDR, one small electrolytic capacitor and a three legged silicon device. I saw precious little else, though there must have been a rectifier of some sort, somewhere, and I'd guess there was a relay. Granted, this was about seven years or more ago. I may still have it somewhere! When you described yours as the simplest you've ever seen, I swear, you could have counted the components in this fake, on the fingers of one hand! if I were to find it, would you like to cast an eye over it?

[@AutoUnder]

Reminds me a bit of the mini photocells that are usually mounted within street light fittings with single core wires coming off it and the actual sensor itself is screwed into a hole on the light fitting

[@BradTech.]

0:50 I was like, "oh wow he's diving right into its insides"

[@smallengine]

“1, 2, 3, 4, 5. It took about 6 seconds.” lol added a second there

[@robt2151]

I have a Turkey-sourced one with a virtually identical instruction leaflet, but with a more rectangular 'dome'. I built it into a waterproof junction box, with a suitably sealed orifice, along with a 12v transformer and the combined unit now powers my 12v patio lights. BTW, have you noticed that, before the EU, electricians had to be 'experienced', now they only have to be 'qualified'.

[@martinwinfield2935]

Thanks great tear down as usual.

[@kradlyn]

I read the title as Duck sensor and was confused...

[@bobdavenport5190]

Read it as Dust sensor, quack-quack, oops.

[@catfish552]

Me too! 🦆🦆

[@skydnir]

same here.

[@AttilaAsztalos]

...Wabbit sensor!

[@uk_phil]

Yep. Me too.

[@bostedtap8399]

eBay; providing material for KZbin vloggers since 1999. Great reverse engineering and optimistic use. Thanks for sharing.

[@bigclivedotcom]

Except that this was from a prominent British supplier.

[@bostedtap8399]

@@bigclivedotcom Agreed, for a reputable UK supplier this is inexcusable; pretty sure these will be on there soon. May I wish you a Merry Christmas and and blooming better 2021.

[@osjakie]

Neat little thing, thanks for that.

[@InssiAjaton]

A 24 V DC relay pulls in (like they all do) at 80% which equals 18 V. The drop out is less standardized, but has to be before the voltage disappears completely. My findings have been anywhere from 2 V to 8 V. Anyway, with exponential charge and discharge, you can usually see different time delays in the two directions. This in addition to what the other component values and ratios cause.

[@johnmurrell3175]

It would be interesting to see the CE mark approval paperwork. Since it will have to be recertified to CUK and or CNI next year as we leave Europe the approval paperwork may be more accessible.

[@jimthesoundman8641]

2:03 I would cut a short piece of extension cord, remove the inner conductors so I only had a jacket. Then I would squirt a bunch of caulk into that sleeve and run the conductors through it, thus making it both waterproof and jacketed. Then run that short cord through a gland and into a junction box.

[@stevenbeaumont1698]

Built some thing like that when i did Physics at School at 13 (1983).

[@bigjd2k]

The simplest light sensors are the thermal types, with a big LDR and a resistor in series across the mains. The resistor is thermally coupled to a temperature compensated microswitch mechanism. Simple, reliable, and for some reason replaced with relatively complex electronic solutions nowadays.

[@andrewradford6267]

Ahh it's not a tiny plant pot. Damn was hoping you'd started doing gardening videos. ;)

[@westinthewest]

BS7671 requires a sheath over the insulation. The cable doesn't need another layer of insulation. The sheath could be another layer of PVC, but we could also choose to use copper (MICC), Lead (PILC) or steel (conduit).

[@rimmersbryggeri]

I think this cout be used to great effect for patio lightin and such applications that ta dry to "damp" but covered. Could make a simular unit but replace the ldr with a RTD and use it for the infra red patio heater. Would probably need a 24hr timer for that in the colder months though.

[@richardkaz2336]

You can sleeve the bundle of wires between a JBox with appropriatle rated flexible conduit. The units would be positioned well out of the reach of anyone accessing it, requiring a ladder and you would isolate the cct before attempting to access the light fitting or JBox. Zeena warrior princess diode.

[@aterack833]

I love that you cut the big print out, I don’t know if I’ve noticed that before but I guess most boards you show are square

[@Uncle-Duncan-Shack]

Nice one Clive, it's a simple and classic design. At 1600 ohms as per the datasheet for the relay, that transistor is going to have an easy life, 22VX22V/1600 ohms = 0.3025 Watts. Magnetic hysteresis with some help from that diode to ensure the gate current goes away completely during the day. it's clever, thanks for tip on how to design an enclosure for my temp, humidity and barometric pressure sensor, the traditional designs are a lot of work and the tolerance to driving rain is an issue unless a lot of attention is given to the louvers. So I am going to make it look like that, with holes in the base for air to in and out past the sensor. Take care, regards from South Africa.

[@eDoc2020]

I can't imagine those tiny surface mount transistors can handle 300mW. Isn't that the limit for the much larger TO-92 packages?

[@Uncle-Duncan-Shack]

@@eDoc2020 Yes SOT23 packages are like 200mW At partial conduction with 11V across the transistor it will dissipate 75 mW. The current through the relay will produce the highest losses when fully energized, during the night. During the day no current flows through the transistor and then there's a brief period of partial conduction at dusk and dawn. The zener diode is going to steam a bit during the day with no load on the dc side. That might get to between 300 and 400 mW. With the copper around it being minimal I would expect that area to turn brown over time. They work, it's a cheap item after all, so it's the level of engineering one gets for the price.

[@richardeblack]

Thank you. Another interesting video. Just made one of these ldr circuits for the lights for the tree outside our village pub. I was thinking of adding a capacitor to 'damp out' sudden light flashes from passing cars and wasn't sure how to. Would that work? I love your videos, they are so informative for an old beginner with a very limited knowledge of electronics. I've learned so much. Thank you.

[@bigclivedotcom]

You probably couldn't make a dusk controller for less than buying a complete one from a company like CPC.

[@citizensteve6713]

Second cap to allow for lightning/ intermittent light sources? Save switching on pain in ass bulbs that take time to re arc like sodium and halide ?

[@Leroys_Stuff]

You got me Big Clive I thought the watermark was the ldr for a second and was how the hell does that work lol

[@eaburtolemiliox]

Could be the different ratings in the condensers due to the timing delay needing to be more or less consistent between different devices, so greater "precision" condensers were sourced to that effect? Given that electrolitics have a wide tolerance in capacity generally

[@instrumenttech4220]

Nice one maybe ask curious hvac guy to send you a Honeywell burner control would love to hear your take on it

[@andrewduncan4230]

I would be interested to see a video off how to take the closeups, the printer and paper you use to produce those clear pics?

[@twocvbloke]

It's perfectly safe to use outdoors, so long as no electricity is used... :P

[@stuc.6592]

It's like a cheap waterproof coat. 100% waterproof so long as you don't wear it in the rain.

[@cfinlay6428]

Oh my word!! I really need to get myself to Specsavers for an updated prescription because I read the intro as a DUST detector and didn't cotton on until you switched off the light. I kept wondering where are the vent holes to let in dust laden air and why on earth would you enclose it in a plastic housing???

[@electrogrim]

As an aside, it was interesting to compare the Hopi display with the light on and off.

[@Jakek200]

That's all thanks to the camera slowing the shutter down in the dark which gets rid of the flicker on the recording.

[@erikdenhouter]

That switch design with LDR is mainly the first design you could find after the transistor came to market at the end of the '50. And it would have been shot down immediately for the gradual raising of the voltage on that relays, and for that sparking contacts. We miss a thyristor as a clamping mechanism; using that under its clamp current you wouldn't even need to reset the thyristor.

[@erikdenhouter]

That cap 100 µF 35 V is also to suppress noise. Without it it would make the relays vibrate on any 50Hz leftover.

[@anoimo9013]

it seems to need some hysteresis to keep it from oscillating when the light level is in between

[@r3tr0nic]

Simple design, reminds me of my first learning with one of those Science Fair kits. I agree on the 1M resistor. I personally like through hole. They should of used multicore flex, but then again this is not something I'd buy to actually use. As with most ebay chinese specials, its good for spares and modifying ;)

[@I_am_Allan]

Could you put some heat shield over each wire, to add more insulation? Or ... put them in a conduit?

[@nigelanscombe8658]

I wonder if this is a similar circuit to the detachable parking lights you could get for cars in the 1960s? It was used to turn a red “parking light” on after dusk.

[@ronaldroberts7221]

If these stop working after a year or so, first check to see if it's covered with bird manure. I recommend any outdoors installation have a clear cover over it that can be thrown away when needed, like half a clear plastic soda bottle.

[@robt2151]

I'm guessing that our host did not read the instruction leaflet - it explains that the black bag is for testing the sensor without having to pray for a convenient eclipse.

[@dlayman101]

please do a video on the simplest way to wire a snubber to a bidirectional DC motor, including the methodology of determining appropriate diode(s)

[@BjornV78]

I think this type of dusk sensor is used indoor, like factories, offices etc.....where there is a skylight used, if the light from the skylight is below the treshold, the electric lights come on. I worked at a place, that used this system to save on electric costs of light, but it was very annoying on cloudy days where the lights are switched on and off multiple times within few minutes.

[@tactileslut]

The silkscreen by the pads for the leads looks like it says ANL.

[@danielm2142]

EDIT: Nevermind, it was in your "Random stuff on my bench." video, at least I'm not crazy... Oh, who am I kidding? I'm getting deja vu, didn't you already make a video on this exact same unit, where you also mentioned that it'd have to be in an enclosure if used by business owners in case a customer/employee grabs the wires? I'm probably dreaming of Bears with dusk switches again.

[@jasonx4937]

In South Africa you can have single insulation as long as it's run inside pvc conduit I'm not sure about the British regulations. But perhaps the aforementioned is an option ?

[@tommiller1315]

Used a 12V version with a transformer, and made my own in a clear plastic peanut butter jar (with a cable gland) 2015. :-)

[@robertwillis4061]

Possible reason for the loose wires is that, in would need to use 4 core flex. It is rare to get 3 core in anything other than positive (brown), negative (blue), earth(green&yellow). It would be very stupid to use the earth wire as the output. So that means going to 4 core with an white or grey additional wire. That would be an additional cost and a redundant earth wire

[@aclam9839]

Would heat shrink on the wires count as double insulated ??

[@IGendel369]

Did you notice that the HOPI doesn't flicker when the lights are off? I guess the flickering has to do with the type of light used in the room plus the camera. That is cool though that without the lights on there is no flickering.

[@skywing959]

I used one of these a few years ago for lights in my chicken coop, it was a 12 volt version though but had the same design. The way I dealt with the single insulated cores was to put heat shrink around all three together. Eventually it stopped working, so I replaced it with a new one which still didn't work, and yet the lights worked if I bypassed it. Very odd since the first sensor worked perfectly for a couple of years. In the end I just got rid of it altogether and used a timer to control the lights instead.

[@TheFool2cool]

You didnt need to worry about single insulated cables if it was a 12v system?

[@davidelsbury2917]

@@TheFool2cool good practice and all that

[@bradgardam1343]

Double insulated has nothing to do with the insulation on the wires, it means that it doesn't need to be earthed.

[@cheeseschrist2303]

Could be used as-is inside a glasshouse or conservatory.

[@TDOBrandano]

Or inside a window to control stairwell and corridor lighting in a building, in parallel with a timer

[@dfpguitar]

the UV would kill the insulation in a glass House and glass houses are also incredibly humid. Meaning there is likely to be condensation inside it.

[@TDOBrandano]

@@dfpguitar Very fair point for the condensation and temperature, but regular glass and many transparent plastics do block most UV light, which is why you need crystal tubes for UV sources.

[@westinthewest]

You can't have un-sheathed wiring whether it's indoors or outdoors. The flex on your TV or kettle cannot show exposed brown and blue cables, and neither can cables for fixed wiring such as this. The sheath must be continuous from the appliance to the plug or wiring enclosure.

[@dfpguitar]

@@TDOBrandano not disputing that glass blocks some UV, but it is clearly not all , because if it was. All the plants in every glasshouse and polytunnel in the world would die. Also, there would be no need for UV coatings on spectacles or even welding masks.

[@Nathan1975Liggy]

Looks like it should be mounted on some sort of pole so the cables go down inside the pole or directly on top above an outside conduit with its bracket slid behind the conduit and attached to the wall. It looks to me to be some sort of conduit sensor with those wires

[@stevea5407]

Could heavy sleeving be used before an outdoor junction box?

[@bigclivedotcom]

It would have to be arranged so that any water finding it's way into the sleeve wouldn't fill the junction box.

[@erdosydani]

I read the title as "dust sensor", and at the half of the video I didn't get what hell is going on here. :D

[@supercables251]

I thought it was "duct sensor" :D

[@doogle2822]

Fit one to your hoover

[@australianstig]

Almost an identical design to one I built in TAFE around 25 years ago

[@LariFariYoutube]

Heatshrink over the leads would make it somewhat double insulated.... And it would helf against UV light. (insualtion gets brittle over time)... Thats a very simple circuit, which in some form or the other, i have used a lot in the past.

[@westinthewest]

The cable doesn't need another layer of insulation. BS7671 only requires one layer of insulation, but it must be covered by a sheath. Double insulation relates to appliances. It sounds like a tedious point of terminology, but a cable's second layer doesn't have to have insulating properties. It is there for mechanical protection.

[@mernok2001]

@@westinthewest In some contries its required that cable sheats must resist 1500V.

[@NickNorton]

Need to start giving names to the Impact/Skid Marks on Clive's Desk. Problem is the 1920*1080 XY Origin may keep changing depending on exact Phone position. Might have to resort to using the somewhat stable BigCliveDotCom as a reference 😁

[@liamguy2820]

Could you not use black rubber (earth cable type) sleeving over all 3 connectors and terminate that into a gland?

[@Mark1024MAK]

With such a simple circuit design, that has no hysteresis or schmitt trigger arrangement, I wonder what it’s performance is like when the light level is very near the switching point. Especially if even a bit of light from the controlled lighting finds its way to the sensor...

[@fd1150]

Bit of a faff but you could use a bit of Bundy10 and blob of resin on the base, then a gland at the end I suppose.

[@nicholasboyarko1680]

It's unfortunate they didn't just put some uvb or another type of outdoor sheathed wire on there. Also a gasket between the case and cover to make it usable outdoors. Alternatively even a larger bezzle so it could mount on a standard light fixture box. So many possibilities, so few acted upon.

[@yoyofargo]

I read the title as "Dusk" sensor and was so confused. I didn't know what a dusk sensor was when I clicked. >_>

[@keithking1985]

whats capping the current on the zener? or is the LDR resistors or the 100omh cap dropper resistor working on it too??? ANYONE?

[@ferrumignis]

The capacitive dropper limits the current.

[@piconano]

...and I made one with only a TL431 setup as a comparator. Didn't think it could get simpler! I was wrong :(

[@theoldbigmoose]

Every time I look at the EU power line colours... I think how easy to remember it would have been if brown was for earth brown return a earth potential, and blue was for blue sky hot ... where the lightning comes from. I'm OK with the earth green/yellow.

[@6F6G]

The single insulated wires could be made quasi-compliant if they were covered in heatshrink and the top sealed with a blob of silicone.

[@a.garland5003]

The famous white box company 😆

[@SKYNET9er]

Do u ever use any of the items you feature? In yer workshop? Or home projects? Or at yer job? Just curious.

[@andyash5675]

It's a good job they put the sun in the sky all that time ago. If they hadn't that thing would have filled up with water. :-D

[@wva5089]

Mind testing turning this off with a laser of various frequency and power?

[@GeneralPurposeVehicl]

Does it fit in a knockout?

[@11Eighty8productions]

Nice

[@jordbjor1]

Trying to find something like that for 3v AAx2 batteries. Haven’t had much luck

[@bigclivedotcom]

I've sometimes just used a plastic bag over battery packs, with the bottom left open to avoid condensation.

[@mistermartin82]

has this featured in a previous video or live stream ?

[@schmittinator1]

Is the test device available with the EU plug?

[@PicaDelphon]

I use these for Flashers Tower Lights, From a Sunny Bright, Down to Night Time Dimmer of 33% of the Flashers..

[@pjeaton58]

Heat shrink the single insulated wires ???

[@brianjonesg8aso403]

Got one of these from Banggood so it is Chinese. As you say CPC should not be handling it unless it was a 12V version.

[@Mark1024MAK]

Or a 24V DC version.

[@nigeljohnson9820]

It rather poor that it does not use a Schmitt trigger to drive the relay. Is there magnet or mechanical hysteresis in the relay contacts. Without this feature, what stops an arc developing across the contacts as they open? I suspect that hiding the LDR between the other component might have been intentional, as it would limit the source of light to that coming from above, reducing the chance of triggering from say car headlights

[@bigclivedotcom]

The relay tends to open and close fairly decisively.

[@nigeljohnson9820]

@@bigclivedotcom I assume this is the result of the gain in the system, however testing with an on/off light source, like a torch, might produce different results to that of a slow sun rise.

[@GrenPara]

Hey Clive, great videos thanks for making them. I have a weird question for you. I have a fiber optic tree and it came with a mr16 12v16watt halogen bulb. My problem is I can only find mrc16 12v 20watt bulbs in Canada. The mrc means bulb comes with a cover. The power adapter is 12v 1700mA with max 20.4VA Would it be safe to use? Thanks in advance Gren

[@Mark1024MAK]

Is the power adapter output AC or DC?

[@GrenPara]

@@Mark1024MAK Hello, Thanks for reply. The power adapter has no markings except the ones! listed it does not even have symbols.

[@Mark1024MAK]

@@GrenPara - well, a 20 Watt lamp is rather close to the rating of the power adapter (20.4VA is the maximum power for a resistive load). But this could be the maximum input power rather than the maximum output power (there will be some losses). But if you can’t find a lower wattage lamp and therefore it’s useless as it is, you have nothing to loose as long as it fails safely if it fails. Transformers used in power adapters (if it’s the heavy type) are supposed to have thermal fuses to protect against overloading or overheating (the fuse is not replaceable). The lightweight adapters use switch mode power supply technology (rather than the heavy mains frequency transformers) which should have overload protection. So it should be safe. But I suggest you keep checking that the power adapter does not get too hot when you use it and don’t leave it unattended. At least, not until you are happy that it’s not getting too hot.

[@GrenPara]

@@Mark1024MAK Hey Mark, Thanks for all the info and help. Ill give it a shot and see how it works. I wont leave it unattended just in case. I will also connect multimeter to see if ac or dc. If I blow power adapter I have higher ones for old devices. Thanks again and have a Great Christmas and Holiday Season.

[@elena6516]

Mr. Clive: Are you or any of your mates into angling at all? Could you do a teardown a bite alarm and receiver for carp fishing? If you are knowledgeable in the RF specialization, could you explain how one might make a bite alarm of one manufacturer communicate with the receiver of another? Would you like me to pay for them?