Inside a simple mechanical time switch
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- čas přidán 4. 03. 2024
- Just a low-tech laid back video showing the inside of a simple mechanical time switch.
Just a cost optimised motor with resistor chosen to suit the local supply voltage, a standard microswitch, and a slightly mistreated LED.
This video is basically me having a shameless skive from real work.
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 CZcams's algorithm quirks, allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators - Věda a technologie
Is anyone else thinking that Clive's loft must be rammed to the rafters with partially working poundland tat? 😂
I think he's got some things in storage but he's probably not as bad as Ashens. 😆
He literally does. He said that he didn't want everything sent because he had so much stuff collecting.
Yes
The crossover we need
No, not at all.
I expect there are 120 pins, 5/hour or 12 mins/pin. So when they say +-6 minutes, I think that's for the variation of the pin/lever mechanism but the clock itself should be accurate. In other words if you set the on time for 08:00 then it will turn on every day between 07:54 and 08:06, but more likely if it turns on at 7:57 on the first day then it will turn on at 7:57 every subsequent day.
Look at 1:02 , look at line markings, its 4 black pins per hour not 5. One black plastic slot is 15 minutes. You cannot expect this mechanism to be more or equally precise as the one with quartz. Mechanical inaccuracy of this device has to be more than 5 minutes per day. 5 / 1440.
Second part of your answer doesnt make sense... if you adjust dial, at 8:00, and you plug it in socket at 8:00, timer will act as a clock. if you use second pin in 8-9. it will turn on right at 8:15. However, tomorrow at 8:00 real time, timer will be at 8:06 or 7:54.
Daily activation will be moved every day by inaccuracy multiplied by number of days.
There is a difference between time precision +-6min/day and the 6min slots for switching.
Somehow Clive should know.
To many fissed liquors? 😂
@@orion310591RS I'll accept your premise that there are 4 pins per hour, I was simply going by the claim of +- 6 minutes.
As to the clock accuracy, the clock has a synchronous motor, it is as accurate as the frequency of the mains power. Such motors (and clocks) are generally accurate to within a few seconds per year. The previous timer for my central heating used this method, the only time I had to adjust it was after a power outage.
The way to set these timers reasonably accurately is to set the clock a few minutes ahead of actual time so that the timer is triggered slightly before the desired time. Then remove power from the clock to adjust it by the amount the timer was out.
A similar exercise could be done for the off time, but only the on or off time can be "accurate", not both.
Looking for a complex answer when a simple one will suffice. I too thought at first it must be some mismatch between the 60Hz UK mains frequency vs. a 50Hz oscillator, but then I realised it’s just the physical variance of the on/off pins as they travel across the switch.
If memory serves, there's a Tom Scott video where he waxes lyrical about the accuracy of the UK's 50hz mains, and how the Teasmade is the pinnacle of human civilization.
As a electrical project engineer I always specified mechanical clocks with spring reserve for exterior lighting. After reading the 1/2" programming manual no one can figure out how to program the digital timeclocks, especially your lowly custodian. Add a photo eye in series to keep the lights off during the day in case they are mis-programmed.
Whats the model name of the mechanical timer you are talking about? Did not know that some come with spring reserve.
@@mofo78536 by mechanical I mean the on/off times are set by pins or cogs, like the one shown, they still have a clock motor, but no other electronics. TORK or Paragon have such models I used to specify. The spring reserve keeps the "clock " turning for some time if power is interrupted for some specified time period.
I agree! Our condo installed walkway lighting. We has a celestial timer delivered with the lights. The electrician exchanged it for a photocell daylight switch.
He could not understand the understand the automatic one's manual.
@@williamterry3177 Yep, I've seen models where you enter GPS coordinates, totally over the top.
I changed my mind on these. I just set one of these up and it was pretty easy... Leviton VPT24, in "Pro" mode you just enter the longitude and latitude in whole degrees and can set on/off times by sunrise and sunset with an offset in minutes. Even has a battery backup and everything.
I remember using one of these to turn my stereo into an alarm clock at one point. Pretty much the only year of my life I got up in time. Now the neighbours get unhappy hearing "Hells Bells" at six in the morning...
I LOVE simple and mechanical. God bless all those who keep making them. If they're made well...
That timing accuracy rating if +\- 6 minutes a day may be the switching jitter, not master timer drift.
The 7 year old in me thanks you to no end for these types of videos!
You must have been a hella nerdy 7 year old lol just like me!
I see them rarely fails as i said on Patreon. Efficiant Reliable and nothing complicated! Very neat timer.
They just start making a ticking sound after a while.
What you pointed out at 7:22, is a ratchet that allows you to forcibly turn the dial around to set the hours of the time on it, making that loud click-buzz in doing so, these will also visibly be an hour clock where they are plugged in
These are wonderful. I used one to turn on an electric blanket so the bed would be warm when I got home exhausted from a night shift and a motorbike commute in the winter.
They say +/- 6 minutes per day but I imagine what they meant to say was there's 6 minutes of 'backlash' in the time selection mechanism in addition to the usual short term drift of the grid frequency.
Also nice surprise to see a mass market consumer electrical device like that have tri-wing screws, all too often I get stuck with stuff that has those outrageous one way screws which makes repairing something or even just inspecting the build quality significantly more time consuming if not completely destructive.
I forget where I learned this trick but a U-shaped spanner bit works fairly well to remove "one-way" screws. It can still be a bit tricky to get them started but it's a great non-destructive method.
All looks cheap and cheerful. Good for low loads like a lamp or something.
I have several to time my Christmas decorations.
I upgraded a few years ago to the digital ones but the battery's expire when left in the drawer the rest of the year, and even if one survives I then have to read the instructions again to set it up.
The mechanical ones win all day long.
Not only do they last, but the 6 or so I have are used for my Christmas Lights, so come out for 6 weeks in Nov and go back late December/January. With the programming being mechanical and left as is when put away, when needed, I just plug them in set the time and they are ready to run again with no extra programming needed.
I have one of these running for almost 6 years non-stop now. Thanks to the motor relying on the mains frequency, it is more accurate than any of my battery powered clocks (excluding radio controlled ones). Very simple and very reliable.
I did an apprenticeship with the GPO in 1964 and those switched were in use then. Love your channel.
I use the same ones for my grow lights they seem to be very reliable
Those mechanical timers are more reliable than the digital ones. Thanks for the video clive! Keep making more of them!
are they? i have a digital one, it has drifted maybe 1 minute over the last year. no biggie.
I changed to digital ones precisely because a mechanical one died quite quickly. It was similar but not the same as this one, and both the resistor and motor coil just went mysteriously open circuit. At the time, I assumed the resistor was a fusible resistor and the winding had originally gone short circuit after back EMF broke down insulation. But Clive's measurements on this one seem to indicate most of the power is supposed to be dissipated in the resistor anyway so I can't guess how both went open circuit on mine.
@@JustinKoenigSilica I mean that the mechanical ones often last longer than digital ones. That is, if they are of good quality. In a mechanical timer there aren't many components that could fail.
I use a digital one that's almost 15 yrs old on a fish tank,they are much more accurate and hold set time in power outages (small battery)
@@user-tz3fd8hm4q just because something is digital doesn't mean it's more likely to fail, IMO. there are well designed mechanisms and poorly designed mechanisms, same for PCBs and components.
I bought ½ dozen similar items for little money from Ikea pre-covid when I was going to be away from home for a few l months. They're great. Keep perfect time - why wouldn't they when the work on 50Hz?
The clock on my brand new oven is about as accurate as a Mickey Mouse kid's watch from the 1950s.
I've run an oil-filled radiator on one with no problems. Although I wouldn't leave that on when I'm not at home.
Thanks Clive. 😊😊😊
Neat and simple and likely much better than a micro-controlled alternative, as long as your life works in 15 minute blocks. Thanks!
Simple but effective. My wife once said that about me but the "effective" bit seems to be missing nowadays! Great video Clive, as always!
I use DIN-rail mounted version one. It has 32768Hz time base crystal (or quartz) and similar mechanism method. Work for 18 years and still going on.
Nice to see that these things are still being made
A couple of years ago, I bought a similar timer. In a couple of months, it started making a little annoying noise. I took it apart and oiled it. Quiet for a few more months then noisy again. It kept accurate time but I could not stand the noise it made. Replaced it with an electronic one - much better results. Normally, I hate setting electronic clocks with the various modes etc but I lucked out on this one - for some reason - it is easy to remember how to adjust it.
its a good day when Big Daddy uploads
Very nice. I just realised that these might be one of the few applications that is left where electromechanics are still common. Much simpler than the one I took apart as a kid.
Those are absolutely ancient and are everywhere. My dad used one in 2012 for aquarium lighting, my graddad had one completely yellowed out in the attic since god knows when, all identical to yours in looks and operation, except different plug.
They're great because you can see the time and settings at a glance. After a few decades they may need lubing though. I also have a really nice Smiths Industries time-til-on timer I use on the washing machine. It of course consumes nothing once it stops and the washing machine starts.
They do start making a bit of noise after a while.
we can admire even the simplest things. you just have to realize that it is more easy to over engeneer things, than to make them simple and reliable.
I remember when electric clocks had larger motors on them, some had like a large flywheel. Then they went to the coil and tiny copper disc . I remember our first clock that had the tiny disk. Plastic gears. They became noisy. I sprayed WD-40 in the gearbox to quieten it. Oh, it worked! But it caused the gears to deteriorate and break.
Timers, I took one apart a long time ago. I don't remember what the clock motor looked like, but it was bigger. The timer I have now has tabs you insert in different places for on and off times. The tabs come off. Definitely not for accuracy. Just to turn things on for a certain length of time, and off when not really needed.
Interesting video!
One just like that has been switching my fish tank lighting for the last 15 years, continuously.
5:40 - "A national standard around the world." - If only there was a word for that. 😉
Hi Clive, An 83 year old Australian resident in Sweden(and an Electrical Engineer), I like you have a hankering to see what is inside little boxes when they fail. Thank you for the dissitation on those timers, I have at least 6 IKEA timers which look identical to the one you had so you have saved me the effort of taking one apart. I have never read the instructions, but know from experience here, the time is accurate to the second, so where they get that 6 minute accuracy, I have no idea. Thanks for a good video.
Yes, we all know how to program these! 😅
I've got a couple of these, and it's interesting to now know what's inside them. First time I've seen one sold in a box.
One big advantage this still has over the typical digital ones is it gives you more switch times. Use a digital and you can set one for the morning, one for the afternoon and that basically it. If you're really lucky it gives you a third one. Meanwhile with the mechanical ones you can switch your device on and off every half hour all day long.
IDK, the latest ~ $10-15 digital timers typically have around 20 separate on and off events and cover a 7 day schedule. They are super accurate and most have a little rechargeable battery to back up the program. These have come a long way compared to early digital timers. Depends on the unit, but some can be a pain to program, although I have one which is amazingly intuitive! repeat cycles and even random cycles are pretty standard features on most.
In Africa we have frequent power outages, and all the mechanical timers have to be reset. The the digital timer is king here because of its memory.
@@professorg8383 The modern digital timers do have lots of features but their accuracy is limited to the cheap watch crystal used. My digital lamp timer is off by 11 minutes but my synchronous motor alarm clock is about 1 minutes behind (and not coincidentally I've had a total of about 1 minute of quick power outages). The best approach IMO is to use the power line when available and revert to quartz only when needed.
@eDoc2020 That's been my experience, too: digital timers are precise, but not necessarily _accurate_. I have one with a seconds indicator, which is pointless since you can't reset the seconds and the thing loses or gains several minutes a month anyway. The synchronous motor ones tend to be the other way around as long as the power doesn't fail: They stay on time once set, but getting them programmed within an accuracy of better than several minutes in the first place is rather challenging, at least for me with the units I've used. Another potential downside is that the mechanical ones I've seen sometimes make gearbox noise, which can be a bit annoying in an otherwise quiet room.
@@eDoc2020 Well, in my experience the digitals I have are right on the money losing no time what so ever. I have a bunch of LED lights working flawlessly, day and night for a couple years and they are always on schedule.
I wouldn't buy this kind of thing off ebay! I tend to use Amazon but I rarely by the cheapest thing they have and I look at reviews. I tend to look at the worst reviews and usually it is from some idiot that didn't read the directions. I used to use mechanicals and at best, you get close to the time you want. Any power loss means you have to reset it. Digitals with an internal battery, stay on time across several hours of power loss,
The only advantage to a mechanical may be a higher current rating, but you can get get digitals with high ratings now.
I'm an old school guy but this is one of those areas that I think the new tech is far better!! But I'm an electrical engineer with a masters and decades of experience, so what do I know!
Great mechanical solutions. Less components, more recycling. Thanks!
Great video. Thank you.
It isn't the *clock motor itself* which is inaccurate, it is just that you can only set the accuracy of the *timing* notches to within an accuracy several minutes, it won't be _precisely_ 8h30m *ON* and 10h45m *OFF* or whatever when you pull the little pegs for at some particular time.
There is a variance in when it _actually_ clicks over the switch one way or the other for each little tab thingy, although they may sometimes fairly close to in sync with _each other,_ in total number of minutes between notches hitting the switch, the actual *wall clock time* is certainly not precisely matched to the index on the housing for an exact on or off time...
I use the mechanical timers to run the Christmas lights (indoor and outdoor) and to switch a couple of interior lights such as table and standard lamps when we’re away. Their inherent inaccuracy gives a sort of random offset to the lights switching which, in my mind, acts as a deterrent to intruders. (I’m too bloody cheap to buy a wireless system when I’ve got all these mech-timers!)
Plus they’ll use less electric and zero WiFi bandwidth, unlike wireless ones! 👍🏻
I had 2 near identical timers from decades ago. One the clock failed, but the second still works and is used for Xmas lights, and for a table lamp for when we are away. It has 4 crosshead screws holding it together.
I have two of these in my house. Thank you!
I have one of these (with the South African round 3-pins) operating my swimming pool pump. I have often seen that the timing is not very stable, although it operates on my solar inverter with a relatively stable 50Hz. And I must admit that I have been tempted to open it to see how the mechanism operates and if it can be improved...
Now I know and can spend my time taking more complex things (that still works!) apart.
Thanks Clive! 🙃
Simple and effective. Just the way we like it.
I have one off those trimmers , had about twenty years or so I have my bedside lamp on it . Wich serves two two purposes one I don’t have get out off bed to turn the light on or off and two a security light when we go on Holliday . They are a fantastic bit off kit fairly cheep and simple
Nothing really to go wrong with them . Oh and it keep good time I have it set to come on at 17.00 and it come on two minutes early set to go off at midnight gos off about three min early give or take a min or two .
I plugged into timer socket a beefy relay to compromise contact wear in the timer. I used my timer with beefy relay as a brain for my xmas lighting.
This is a lovely throwback to your first videos, I love feeling like I'm just stood next to you while you do your thing, it's very calming. A 50% brain video so it's easy to follow along when the other 50% is unavailable 😅
Oh man I loved mechanical timer switches. The Washer and Dryer used to have these timers with cogs that opened and closed contacts for the cycles. And even better they never failed unless the motor driving the device burned out.
Those things are absolutely durable. The synchronous clock mechanism is accurate (as good as the old Smiths Sectric); the only "real" failure point is the microswitch and the life of those contacts can be helped by a simple RC network. All of ours have .25 " slide on connectors, so possibly ours are upmarket versions (although bought from our local Reject Shop many decades ago).
I've had two mechanical time switches fail on me personally. Both times it was gear failure, the switch mechanism was perfectly fine in both cases.
Thank you, keep working.
i have a few of them of various ages, i picked up 2 'smiths' ones from a car boot sale and they probably date from the 80s, one even has unshielded pins! one had a capacitor for the motor dropper and it had gone very low capacity, a replacement pinched from another physically damaged timer cured it , the other one used a resistor dropper
I like these mechanical timers, but had to swap mine with digital timers because they were losing an hour a month due to average frequency of mains being slightly out of spec.
There are apparently 5 possible timing settings/pin positions for each hour, so their spacing is 12 minutes. For the ACCURACY of the timing of each position, given the construction method and materials, the best that could be expected is +/- 6 minutes. The repeatability (with a synchronous motor) is obviously much better.
Such a time switch was one of my first electrics projects. When I was a kid my parents had one and it had no on or off switch. I drilled a hole in it and fitted a on-switch. That very time switch is still in working order.
I took apart one similar to this a few days ago, and noted that the microswitch was rated for 16 amps, despite the timeswitch itself being rated for 13 amps maximum. Presumably that's because the sockets are rated for 13 amps too, so anything that plugs into them can't legally be rated higher than that, even if it uses components that are. The 16 amp microswitches are the same (or at least seem to be the same) as used in some types of electric showers to switch the heating elements on and off. So they should be fine to use with resistive loads of that type. I have been using one of these mechanical timeswitches to control my immersion heater, which is 3 kW, right on the limit of what the timeswitch is rated for, but well within what the microswitch inside it can cope with. Works just fine and has been doing so for years.
Check on it from time to time. I've come across units used with immersion heaters that did fail after long use.
I have one of these, I used to have it connected to a lamp in my living room. The are a great invention, my biggest complaint about them is due to my vision impairment, it's often a bit tricky for me to see exactly what time you set the unit to, mine also used removable pins which aren't hard to lose. I'm glad to see timers like this with toggle switches for the on and off timer settings, you won't lose the pins. These days I use a WeMo switch, because it's easier for me to program from my iPhone, but I can understand why people would still rather use mechanical timers like this.
I carry those mechanical time switches in my car, they are brilliant as a temporary replacement when fridge freezer thermostats fail , bypass stat or electronic board. You can set one of these with 1 hour on 1 hour off all day and few hours off at night. Means fridge will work till stat or board turns up. Ps that's quite a good one it's got a microswitch. Some District have a couple of cheap copper contacts being mushed together . Thanks for posting
The one-way mechanism you pointed out (or a different one) is probably so you can turn the timer wheel to set it. Also the 6 minutes is probably the timing tolerance for turning on and off; I wouldn’t think that the actual synchronous motor is off by that much per day.
I think it's where you make the pause while saying it: either a tamper-proof screw-driver, that is a screw-driver you can't put where you shouldn't, or a tamper-proof-screw driver
Neat didn't know they made those anymore!
Bought one of these for about a fiver from Poundworld. Very reliable and does the job.
I got one of these that was iffy a while back. Turns out it was actually the mechanical bit on the front. I decided to take it apart and it was clipped together. I got rhe clips iff and started levering the back off. There was a sort of "sploing" noise ans a small fountain of even smaller springs that went absolutely everywhere. By everywhere I mean for example one was found in the kitchen under the cooker.. Several were found under book cases and the sofa. It ha9 96 of these springs and 4 are still missing. I suspect one under the TV unit but bugger knows where the rest are.
I love these things,
a true technological marvel
Manually setting every pin is a Joy
Trying to set a 16 hr on, 8 off for the plants 🌿
Then leave it switched off until time sync is reached.
Normally trigger the 8 hr off at exactly 10pm
For a 6 Am power up. And its good for the whole season.
And add a threeway adaptor into the one timer.
To run more lights or fan
The 8-12 minute +/- flaw is not really noticeable
As sun rise changes by 4 minutes daily
From a growers point.
The inaccuracies are in the mechanism, if the grid is maintaining frequency average over the year
I have the exact same one, except with Australian plug and socket
Same dial, same side "switch"
I have that exact model, from Tesco. It is actually fairly accurate, I have it running a charger during the cheap hours at night.
Always interesting m8. 🙂
In many places grid operators are no longer required to do daily "make-up cycles". That may explain the +/-6 minutes spec since any deviation in the power line from 4,320,000 cycles per day (50Hz) or 5,184,000 cycles per day (60Hz) will adversely effect accuracy of anything using a synchronous motor or cycle-counting scheme. For example, my ancient X10 controllers, which once kept perfect time, have been running fast since mid-2000s.
wow. that was so interesting i'm off to take mine apart now to compare. cheers BC.
I believe the clock is driven by a synchronous motor; the six minutes is likely the resolution of the switch positions. Did you count the switch levers?
Running 600w of HID ballasts on these cheapy timers. Never a problem, very reliable. There's a relatively new digital version that allows ON periods of just 10 seconds, and still just as chrap. Perfect for irrigation pumps.
If there are power factor correction capacitors on the ballasts it can cause contact welding.
Basically a thermostat of sorts.
I got a similar timer for my 1.75 Kv space heater. Works very well. Every micle maks a mucle.
Send the bits over to us in Portugal for spares Clivey, I blew ours up a couple of weeks ago! It didn't do bad though, we had it donkeys years!
I had one of mine apart not very long ago to check for problems and it looked pretty much the same as yours too, simple switch and all
I bought two plug in time switch from a DIY store because they come in a pack of two and I got what I payed for. The plastic black bits you slide for off and on that are around the 24 hour ring they have worn so as the timer ring turn it doesn't throw the leaver over enough to turn on what ever I have plug in. But the timer does keep very good time but it doesn't always turn things on or off
I call those screw drivers 'Warranty Voiders". They do come in handy though.
The thermostat broke on my freezer 10 years ago and since then I have used one of these to turn it on and off and works a treat and is more efficient than the thermostat ever was. I use 30% less juice for the same effect.
Got a quite similar one at home. It's accurate to one or two minutes a year.
I got an American Harbor Freight version of that. I wanted to set it up so one side will turn on and the other turn off then alternate. The internal switch was marked NO, NC but when I pulled it apart only the NO side had contacts. Some time I need to find the version of the switch that has the NO, NC contacts so I can replace the switch. The goal is to have two fans and alternate one or the other. With out making an overly complicated project.
We use a West German (yes it is that old) Suevia timer. It has a very obvious time drift like this one and has to be readjusted every day.
The inaccuracy may be due to positional inaccuracy of the switch/tab elements and not speed inaccuracy in the motor.
I believe so. The mechanism is reliable but sloppy.
IIRC the inaccuracy is from the line frequency nit the synchronous motor. Most countries allow the power line 50Hz to drift down under heavy load with catchup when the load is less. The guarantee is that 24hrs will be accurate but point to point time may differ from real by a few minutes. Countries do vary as to their tolerance with no slippage allowed in some, e.g., most (all?) of the USA maintains 60Kz as a solid standard.
I loves me a nice shaded pole motor. I'm guessing the manufacturers just swap out the reduction gear box for 50Hz vs 60Hz regions?
I think the stated accuracy may be due to the mechanical nature of the mechanism, not the motor's synchronization with the power grid. Just as with any mechanical alarm clock, it could trip plus or minus a few minutes of the set time on any given cycle, with a Gaussian distribution over many cycles.
I see you've reached gold play button subscriber status. When did this happen?! Congratulations!
Those timer segments almost remind me of how a commutator on a brushed motor is constructed.
Hi Clive. Love your videos. I just took apart a failed IKEA 24 hour timer, and all the parts (including several gears) went flying all over the place. I figured out where everything went and got it back together. Still fails, gear slip. They wear out.
At 7:20, you show the 'Freewheel.' It alllows you to advance the timer wheel clockwise (not anticlockwise) without engaging all the gears. It makes that funny clicking noise when you set the time. The motor is self starting in the correct direction.
I guess, the 6minute accuracy is about the mechanical switching, because of imprefect spacing of these black teeth. Every one is 15 minutes, so even the slightest move to the side or not fully pressing them down can and will affect the switching accuracy. I had one of these timers to control the power to a boiler. Never let me down, to be honest, and I don't remember to have corrected the time for many years, so I guess the motor is really doing it's job. On the other hand I sometimes used to turn the wheel manually, because using the override switch and forgetting about it made the water too hot 😅
They are about to film a new Highlander movie. I think "Big Clive" should be the brains that the immortals go to for electrical system advise!
Thanks :)
Bring mine out every year to run the Christmas lights, I have three on the go and the accuracy is pretty good. An accuracy tolerance of 6 minutes a day seems to be way off as mine don't vary by a minute or so over a 3 week period 😊
I have a couple that are at least 20 years old, more likely 30, and still work perfectly well, unlike the short lived electronic ones.
I paid about fifteen quid apiece for them and see them now in Home Bargains for a couple of quid.
You can get them for $5 at Harbor Freight in the US. I have one running a 5 W LED that's been keeping my bioluminescent algae alive and happy for years now. Incredibly, it keeps time more accurately than the various quartz based clocks around the house.
Line frequency is always going to be more accurate than a quartz clock. At least until the power runs out.
I've been using a Digital one for ages but I once had a mechanical one that used red and green pegs you had to put in either the outer or inner circumference which had many tiny holes.
Very quiet when I first bought one of these, has slowly become louder. Its on 24/7.
I think they mean the acuracy of the on and off moments. So the per day is not needed.
There were some digital timers on eBay (many suppliers, many "brands" but all the same) that were horrendous:
The digital display was upside down (in the Australian pin version, maybe that was the only version with the problem)
The switch was in the neutral line, so the appliance remained live when off.
They were cheap & worked wonderfully so i bought several and modified the internals, it was only a matter of turning the display around and swappkng wires...but they were potential death traps.
Edit: they were temperature controllers, not timers.
I havs more than one of these and they are pretty accuate at timekeeping.
You talking about them overcomplicating things reminds me of the last time I tried to buy just a simple table clock.
It seems like you can't really buy a basic synchronous motor clock anymore. They're all overcomplicated with microcontrollers and DC power supplies.
Simple thing inside but could be a be neater. 👍👍
Mains frequency is a serious business its' really accurate and if it runs even slightly over or under clocked throughout the day, the electricity supplier will compensate by increasing or decreasing the frequency to make up the difference over a 24hr period. a heck of a lot of devices used to work like this timer. I have one at home and its accurate over months. (to the quarter hour)
If you are using one of these to turn lights on and off while you are away from home (vacation, etc.), you'd actually want the timing to vary some each day. It gives a more accurate impression that someone is actually home. If a potential burglar sees lights going on and off at exact times each day, they can almost be certain that no one is home.
06:30 Was anyone else hoping those little black things were going to go 'ping' in all directions..? 🤣
Yours was a very chap, there are some much better ones (for DIY/modifications) where they have a big square module including the microswitch, timer and motor in one unit, there are three terminals. A resistor is connected on the outside (after terminals) and the live (or neutral depending on orientation (Sweden)) going to the switch and the socket.
I love these small timers (that I described) as you can remove the module and put it in your own electronics, some modifications need to be done, and that is removing a little metal piece connecting the switch and the coil, then you solder on two wires for the coil, Wich can be connected to an ac transformer. I use one of those for my, what's it called... Cubbord or a wooden box, idk, but I have a code lock on it to lock the door, and at different times of the day a code either starts or stops working, I also have lights and a battery backup for it, and I'm realizing this is a very long comment...
Simple, very little to go wrong! but it does need the chip to flash the led in SOS mode!
a national standard around the world... there should be a word for that... like ehm... can't think of it :p