Timer switches: literally just a clock and a switch

Worthy of note: the motor-driven timers consume 3W constantly - and with modern LED lighting, that means that depending on what you want the timer to do... it may not save any energy! If you use it to control a lamp with a single 5W bulb for 8 hours day, then it saves 80 watt-hours while also consuming 72 watt-hours. In that specific case, you might as well just leave the light on all day and forget having a timer!

The absolutely ceaseless smattering of puns is why I love this channel.

When I was a kid we called those "coffee timers", at least in my family. Namely, it was a timer into which you plugged the coffee pot. A few years ago I went to the store and asked where they had "coffee timers". They looked at me like I was speaking Greek.

I would be willing to say Intermatic likely was the first company that made timer switches. They are still around today making things like pool timers, but their staple is delay on, delay off, and even more sophisticated relays! EDIT: Tab storage - It's literally right there!!!! To store the tabs, you set the tab for on, and then place the rest of the "on" tabs in the section where it will be on... Then set your off time and place the remaining "off" tabs in the section where it will be off. Too bad they never bothered to put that in the instructions...

Thank you for always making me interested in things I never even notice. These devices are so standard in terrarium or aquarium setups that I took them for granted. They're surprisingly nifty!!

It is kind of heart warming to see how much well deserved attention is given to such a humble everyday item. I can almost see them blush as you present their simple innards.

If you want a timing sequence that has a period longer than 24 hours, you can plug one timer into another. The second timer runs only when it gets current from the first. You can get really complicated switching patterns that way, but it is really confusing...

I'm so happy to have stumbled upon your channel a couple months ago. I've learned so many things about the complexity of things I took for granted. And I find myself more curious than ever about how things work nowadays.

These videos are always so interesting, and I always look forward to your deep dives into historical tech. They remind me of episodes of the old British show The Secret Life of Machines.

I’m 47 and those Intermatics gave me a powerful blast of nostalgia. My grandfather used to use those a bunch in his house. I remember walking around as a little kid thinking they looked so cool and complicated. Got older, he passed, and I found a few of his laying around. They are very cool, and fairly bullet proof. I’d much much rather have that ‘70s Intermatic than the one with the digital programmable display. Those are a pain to program.. and then after you learn it you forget the next year when you have to do it again. Now a days of course, smart home IoT devices do all this. Yep, nostalgia.

I’d really love to see an ice maker episode! They’ve always fascinated me and it would be very cool to see you do it!

You can store the removable tabs right next to the in-use tabs. For example put 3 ON tabs together right after the desired ON time and 3 OFF tabs together right after the desired OFF time. That's what I do for my outdoor landscape light transformer timer.

It's a testament to your video making prowess and progress that such a polished and entertaining video is deemed a "No Effort" video.

Another enjoyable dive into a common, overlooked household gadget. I really like the early "pre wall wart" style Intermatic Time-Alls that sat on a table and had a power cord. Just neater IMO.

I was hoping you would cover my favorite doo--dad, the timer I use for my holiday (Halloween and Chrismas) lights: it plugs into the wall (or in my case my outdoor plug) and has three outlets on it. It also has a dial that allows you to either turn it on, or set it to 2, 4, 6, 8 or "all night". It has an electric eye that detects when it gets dark and turns on the lights for the specified time. It is one of the most insanely useful things I have ever bought...

I use an outdoor version of the 3rd mechanical one with the 48 pins to control my pool pump. I have it set to run for one hour at 3 different times each day. Pretty handy and quite reliable!

You are so cool & I love this amazing channel that you’ve built. You rock so much & I’m so glad that you make this stuff for us. Been watching you for awhile now & im so thankful I found this channel. It’s so intricate & cool & interesting even when the stuff is “obsolete” or “redundant.” Thank you for bringing us many many hours of curiosity & joy in learning. In this case the info is also useful, but it’s almost always so fascinating.

I can't believe how you weren't absolutely furious with how these digital timers are unintuitive. Maybe it's just these I have ever used. And as always, amazing video!

Hey, it's the timer I sent you like 3 years ago! 😅 Thank you so much for such a cool video involving the old 1970's timer. Your "why are electric switches clicky" video had just come out and I figured you might find something interesting to say about the mechanism. Wow, wasn't expecting a whole video on timer switches as I didn't think there was much to them! Also total win on the plug detents.

I've got a bunch of the type with the removable tabs. We put them on a few lights any time we'll be out of town for more than a few days so lights come on and off, making it look like people are home to reduce the chance of someone attempting to burgle. Also useful for my grow lights I use to grow herbs in the winter (no window sunlight here in NY winter).

I really like these videos about interesting and useful technology that we often overlook! Since you were talking about clocks again, I would love to see a video about mechanical clocks and their time keeping, but more specifically, how they have improved over time, comparing springs vs. weights, and most notably, one of the most accurate escapements: the double three legged gravity escapement that was designed by Edmund Beckett Denison.

Alec, it is unbelievable to me how we have at some point in our lives probably had the same ward niche interest in some seemingly mundane object and this is another one. I've gone through periods of mini obsessions with timer switches several times, to the point that I have a collection of them. Tons of intermatic Time-All's and plenty of other weird ones, like one particularly unique very old 1930's? Art Deco one with a mechanical wind up clock, I love these things!

I love these analog, ultra-mechanical timers. I have that first one and it's great for setting up an indoor grow lamp for plants.

I remember those mechanical timers well, mainly because my parents had a handful of them around the house when I was growing up, and KEPT them around for years. I wouldn't be surprised at all if they still have at least one of them in a drawer somewhere, and that they've actually used it to turn their lights on when on vacation in recent years. They were very much like that first timer you demonstrated, though I don't think any of them were that exact model. But it's really cool now to finally see how they work!

The removable tabs can be stored on the timer. Just insert all the spare "on" taps into a time span where its already on, and the spare off ones into a time span where its already off. This has issues if you only want it to be on or off for a very short period each day, but otherwise works pretty well (or at least it did for me back when I used the exact timer you showed). Sadly they tended to wear out pretty fast when used 24/7. Great for seasonal use though.

I bought a digital timer switch recently, actually a pair of them because they only came in pairs, and I found out that despite having 8 buttons on them, you can't set different times for different days, and you have to plug them in one day a month if you aren't using them to keep the internal battery alive, so now I have a spare timer plug in a random socket

We have some hybrid electronic/mechanical timers you might like. They use the same timer as that electronic one you showed, but instead of a relay they have a linear motor and mounting bracket for a light switch. When it's time to actuate the motor moves some bars with wheels which flips the switch.

While I appreciated the accuracy and thoroughness, "morphosisticsted" is my key takeaway. Joking sside, I install a lot of intermatic commercial mechanical timers. I believe the key difference between them and the consumer units you investigated is that the consumer units bare a horsepower rating. Maybe in a future video you could discuss the difference between units that can handle inrush current vs timers that are only good for small groups of lights?

I like the mention of the use for sign lighting. Having worked in the sign business most of my life, I can definitely say that photocells are not a great solution as they do not last long at all. Most people who want to go the route of photocells instead of timers do it just because it’s cheaper and doesn’t require access into the breaker panel. I will always try to pitch timers just because of their reliability

I have the second timer. You store the extra tabs by just plugging them into the dial. As you pointed out, they perform a no-op if they are on a part of the dial where the event they handle is already triggered.

I always liked how these very old timers with mechanical switches had a bit of natural variance in their on/off times as they worked to overcome the force of toggling... A little deviation in the times can make for a more natural look than hard-timed perfection of newfangled digital timers. (Although now we have programmed-in randomness on some units I've seen, to make lights look more "human" which is also neat)

If you want to store the tabs and not mess up the timing, just put both « on » tabs next to each other and both « off » tabs next to each other. Since they won’t mess up the actual timing, you can just use the spaces between the first on/off switches as storage.

Really enjoy these deep dives into every day items. Your presentation is perfect

Every time I watch your channel it makes me happy. Not only do you have an enjoyable and pacific presentation style, but it's fun to see such clever engineering behind so many commonplace devices

Always wonder how they works inside, I had my doubts, but you showed me I was mostly right. Like always another amazing video. Might be no effort, but it was worth watching.

Great topic, and great video, as always! My family has been using these kinds of timers since the late 1960s, when my grandparents first found out about them. (Religious Jews don't turn electrical things on and off on sabbath and holidays, so we use these timers to make life on those days more convenient.) After doing a bit of research to identify the picture burned into my brain, I think my grandparents' first one was an Intermatic Time-All Model A-211, which had a power cord, stood upright on molded-in feet, looked something like a big alarm clock and had the override switch on the right side. That timer might've outlasted my grandparents. My wife bought a timer exactly like your first one when she was in college in the mid 1980s. She still had it when we got married, and we used it (dare I say religiously? 🤣) for about 20 years, at which point it failed. I don't remember if one of the plastic parts of the switch broke off or the motor burned out, but whatever killed it, she definitely got her money's worth out of it. At some point, I bought two timers exactly like your second. Each came with two sets of trippers, and I did exactly what you implied in the video, and when I needed one of the timers to turn a light on and off three times over a 24-hour period, I borrowed two trippers from the other timer. I also discovered, as you mentioned, that those trippers are ridiculously easy to lose, so at this point I think I have one timer with two sets of trippers on its dial and the other has two OFF triippers (but no ON trippers) on its dial. Oh, well... I also have timers similar to, but not exactly like, your last two. In addition, I have one programmable in-wall timer that replaces a light switch. Acquiring that was something of a production. My first such timer was a relatively simple model that got its power from the household current. That was fine until CFL spiral bulbs that fit into most fixtures came out, and I quickly discovered that my wall timer was incompatible with those. Apparently, it depended on the filament resistance of incandescent bulbs in some way, and having even one CFL in my dining room chandelier caused all the bulbs to flicker and the timer to make funny noises. So, I had to stick with incandescent bulbs in that fixture until I discovered a wall timer that used a pair of AA batteries to run the clock and operate a mechanical switch to turn the lights on and off. That worked fine no matter what kind of bulbs I put in the light fixture. It was a bit annoying in that the switch made a curious sound when turned the lights on or off, which took some getting used to, and it went through several sets of batteries per year. It lasted for about 10 years, after which the plastic hook that held the battery compartment in broke, and I had to replace it. The updated model offers relatively complex programming, auto daylight savings time adjustment (obsolete since the last DST rules change), switching the lights at dawn and dusk, and a lot of other features. It uses some sort of camera battery instead of AAs, but it also uses a more efficient electronic switch instead of a mechanical one, so each battery lasts several years.

Something I love about your videos (among other things) is how there's a sort of "Technology Connections curriculum," for a lack of a better words, that builds off of previous knowledge I already know (or have the opportunity to learn by clicking the i card). There's almost a certain chronology to it, yet it doesn't necessitate watching every video in order. Additionally, this enhances my knowledge about all of the *connections* between various *technologies.* Hmm, I guess that's why it's called that...

We have a few that are like the second and third versions. I really like the ones with the push buttons. I have one on my ancient coffee maker and another to heat the bathroom in the morning. We also have one with the removable tabs to run our pond and water features I also have a really nice digital one but it's so complicated I don't use it

There are 96 of these "switches" on the DeLonghi Oil filled heater I have , each for every 15 minutes , and very , very tiny to pull or push each up or down... they took it to a whole new level!

This is by far, my favorite youtube channel. Never stop what you do.

Hey there! Thanks for the videos; love your choice of topics and the deep dives you take. I use one of these timers for my Christmas lights. It's a little different from the ones you showed. It has forty-eight fixed tabs that can be set individually in half-hour increments. That allows the device to be turned off and on at different times and intervals throughout the day. I'm not quite sure why you'd want that level of control, but it just goes to show that there is no limit to human ingenuity. Thanks again and keep up the great work! It is truly appreciated.

Interesting, I have a k-mart branded one that appears to be of a similar age to the first intermatic you showed (circa 1970s). It has 24 switches, one for each hour.

Great content like always! but if I may make a humble suggestion that may help you out next time you are using the "peg /tab" style version. I hate losing small pieces as well and I understand your frustration with the lack of "extra peg/tab" storage on the back of the Timer switch, however there is actually "intergraded onboard" peg storage in the front of the timer. To use this storage all you need to do is put all the green tabs in after you set the time you want it to come on and all the red tabs in after the time you want it off. Example you want the timer to come on at 1pm and go off at 5pm, And your timer came with 3 green tabs and 3 red tabs. Put the green tabs in at 1pm, and another green tab at 1:30pm or 2pm , and the Third green tab in the slot for 2:30pm or 3 pm. Then take the first red tab and place it at 5pm , the second at 6, and the third red tab at 7 . As you stated @ 3:33 of your video the On tabs can only turn it on so you can have them slotted one right after the other its ok the other two tabs wont actually make a connection with anything, and the same is true for the Red tabs, after the first red tab turns it off the following red tabs will not make contact, so its like they just get to "ride" a very small Ferris wheel as they should never come in contact with the switch. I hope that my example helps this concept make sense, (its very wordy, and might not be as clear as I would of liked it to be, sorry) . You have taught me so many things over the years, and I just want to share that trick with you , keep up the great work, and thank you for all the knowledge through the years!

ive previously used a timer like the last mechanical one you showed, and ive found that they tend to drift quite a bit almost an hour in just a few months for the two ive ever used

I have a few of those with the removal tabs. They work great, and came in handy when I did a lot of travelling.

Mechanical ones are really practical and have a user interface that is hard to beat. The digital ones seem versatile, but one has to figure out how to set it up.

Wonderful! Clock switches are the first steps into automation. I remember adapting one to control the millivolt circuit on a gas heater in an apartment I was renting. One of those through the wall vented heaters with no electrical connection. So it would turn on before I had to get out of bed in the morning...

I always enjoy your comedic timing. It runs until the moment just before it becomes tremendous cringe and then moves on. Dunno how that timing gets nailed down but I like it

I have some BNLink timers from Amazon and they have the little tabs that you push up/down. When you push or pull one of the tabs at the current time, the tab also pushes the switch up and down (instead of the switch getting in the way like on older models). So the tabs don't interact with a rotary switch/knob, instead they pull a lever back and forth. When the override switch is on, the lever moves out of the way so that the tabs can't influence it.

I shame to admit but I was skeptical about this video. I mean, timer switches? But that was educational and entertaining as always. Especially the way you introduced the evolution of this devise. Alec You are a natural born teacher and I say it with my up most respect. Thank you for all your wonderful videos.

the big brother of this is the sangamo weston street light timer and outdoor lighting timer, its excetionally well made and the on/off tabs are moved mechanically by some extra curved metal pieces to account for seasonal variation in dawn/dusk. Thinking of carparks they even added a little wheel to exclude days of the week. Everything in it is mechanical and basic but btilliant. its been updated over the years but i like the 70s versions the best

mechanical timers are great. I'd actually use them, if those motors wouldn't produce noise 24/7. So digital it is for me! (also I'm now somewhat hooked onto home automation - so now everything is digital for me, comes at double the price and I'm constantly switching batteries and wondering why nothing works. FUN!)

The knob on that one is so much better than the way the ones I have work. All the modern ones I looked at when shopping for some this year have a switch that can be set to AUTO or ON, which means if you want to turn it on during the off times, you have to switch it back to AUTO, and if you want to turn it off during the on times, you have to unplug it and lose track of the time or change the settings and then lose your settings. Although the newer ones I have do have the benefit of being able to program multiple on and off times per day.

Half of your videos I'm excited to learn how a thing works. The other half I'm like, "yeah, yeah, I bet I know how this works," but then not only do I still learn a whole bunch, but you make it entertaining. You rock :)

I remember these timers. I remember my grandparents using these back in the 70’s to deter possible thieves. If they saw lights coming on and going off they would think someone was home.

Finding a device that uses the spade holes is honestly very exciting.

Complex enough to be interesting but just simple enough (with your explanation) for me to comprehend. Beautifully presented!

We have one of these (or rather a clone) controlling our bathroom floor heating, I've always wondered how they work. Great video!

Thank you, thank you. As always, your topics are concise with wit and charm that elevates beyond mere nuts & bolts. (story time) In the other millennium, we were young and broke. Had a bed roll instead of a bed and a radio instead of an alarm clock radio. What we did have was a... Timer Switch. Simply put when we heard music (6am), it was time to get up. This was also the entertainment center for guests when playing (high stakes) Monopoly.

After rewatching the "holes in plugs" video just yesterday, I was not expected to find relief from my resulting frustration so soon and surprising.

I use a version of those timers that have a ring of many captive tabs. Popping up the tabs sets the schedule. You can set multiple schedules in roughly 30 minute increments.

The clicky down type timers are still routinely used here (UK) on boilers (gas furnace) to set the on and off times for your heating. Coupled with a thermostat that will turn it off and on too.

I have that exact timer with the removable tabs to control the light on one of my aquariums. On my other, I had a sliding-tab timer that was at least 30 years old, but I think it just wore out internally and stopped working, so I bought a power strip with a built-in timer, especially made for aquariums. It has four outlets that switch back and forth between on and off when the timer tells them. In other words, two are on, two are off at any given time, then when the timer says, they switch. The idea is that some people have blue lights on their aquariums at night.

I bought a version of timer #3 for a trip once, to put a lamp on, and I've continued using it ever since. It's just too convenient to have the lamp come on at dusk and go off around the time I go to sleep. It's also a great reminder to go to sleep, for us night owl types. It has some annoying drawbacks, though. As stated, power outages throw it off. Even better - mine is plugged into an outlet by the front window. My dog likes to lay against the window sill, waiting for me to get home. So, he occasionally pushes several of the switch positions in, and then it takes me a few minutes to figure out why my lamp is acting strangely. Lol

We have almost that exact third timer (with the depressible switches) and it is connected to a floor lamp that clicks on at 7:30 AM and wakes me up, and shuts itself off at 8:30 AM. In combination with a Fitbit and a silent alarm, mornings are much more pleasant now. Instant sunrise!

The ones with the individual pins that pull out are handy to use with an iron that doesn't have an auto-off switch. When using your iron, just plug it into a timer that only has Off pins set. Set the Off pin for the maximum time you'll be using the iron. If you forget to unplug the iron or turn it off, you have a safety backup.

The nice thing about the mechanical timers is they work with both resistive and inductive loads. Maybe they're better now but I tried using an electronic timer to control fluorescent aquarium lights and when the lights turned on it would crash the timer. So I went back to the old mechanical one, which is 100% reliable.

That gear-reduction cluster is needed to make the wheel rotate at the correct speed of 1 rpd, but it also adds a huge amount of mechanical advantage, allowing the tiny motor to easily push the levers or buttons in the crudely made device, which require some force to actuate.

One of the cool options on the digital ones I had, was to add a "random" 0-30 minutes to each setting, so that the timing was "more realistic" if burglars were watching the house. Or something. It was kinda fun anyway. But a couple of years ago I needed to buy a new timer plug, and I was dismayed that it was cheaper (and with lower running costs) to buy a smart plug. Hey, it works. It still has an override physical button on it at least.

Really informative and technical review of a vintage timer! I appreciate your videos! Thankyou :)

I love the mechanical ones as they’re so much more intuitive to set up compared to the electronic ones

I'm glad that you found receptacles that engage with the holes in the plugs! You and I both seem to have been suspicious about this for years (well, more years for me), so it's nice to find at least something that actually uses the holes.

Those built-in-tiny-tab designs used to be pretty common on household boilers in the UK. I've lived in flats with them, and they were a very handy way to pre-set having your heating come on in the winter. Much better than my current system, wherein my boiler reads the programme from a thermostat across the flat from it -- but sometimes decides to connect to my neighbour's thermostat instead, and heat to their programme instead of mine. Meanwhile, I'm still enjoying a plug-in mechanical-tab timer switch in Scottish winters, which I have plugged into a SAD lamp so that it turns on before my alarm in the mornings, so I don't have to get up in the dark.

Our house actually, interestingly, has two of these mechanical timer switches, likely added when the house was remodeled in the 60's to late 70's, in an in-wall configuration, not sure what they do if anything but it's still interesting.

We've used these for years run block heaters on the big trucks and tractors (1600 watts). Just like the one you showed, but a more recent version. They work quite well, although after a few years they start having problems when it's -40 and sometimes stall or get really slow. I've also got one running a light (because the stupid LED won't work with the day-night sensor that is supposedly meant for LED). By the way the newer analog switchers you showed don't like -40 at all, especially the one with the 48 little tabs.

We use the newest tab version for our pet vaporizers. They turn on around feeding time, and at midnight/noon for some extra in-between calming spray in the air. They're super nifty.

Not gonna lie, this channel is bringing up the charm and the cleverness in older devices, I like them a little more every time I learn about them.

I have had that second white one my entire life and since it’s the only one I’ve ever needed I thought it was the pinnacle of outlet timer technology. The digital one blew my mind!😂

Gotta say, I agree with you on the pleasing simplicity of a timer that just is clock-switch and nothing else.

Another good video, Alec. First, back in the ‘70s, my family stayed at a friend’s cottage and they had the first timer you showed. And I thought they were really neat and modern. I was 10. Anyway, Second, I also noted when you opened that one up there was the CSA logo (Canadian Standards Association) on the motor housing so I presume this unit was sold in Canada. Eh.

Thanks for the video! Been using these things for 4 decades but now I use plugs that work with Google assistant. Still really cool to see how they work.

Truly enjoyable video. I have had and used all of these types of timers. I still have several of the type with the push / pull tabs. And recently picked up a digital version for Christmas lights, and it is for me the most difficult to program. I have several tansformers with the pin type timers built in for out door lighting. Over the years the timers seem to go bad, so I would by a new transformer for $60 - $80. Then the idea struck me to just run the transformer thru the timer.

Oh, man, I remember those things. My family had a set of them, that exact model, but with avocado green cases. I always wondered how they worked, and now I know!

I worked with a variant of those devices at a hotel: it was an alarm clock with slidable tabs all around the dial at fifteen minute intervals. We used it to make manual wake-up calls to rooms. Each tab set would make it buzz until we hit a switch to silence it, then we would look at a list to see which rooms to call. Four-star service, baby!

I have the digital version of it (no need for gearing to wear out), which turns on and off, outside LED rope light I installed on my balcony. It's quite handy instead of letting it stay on during the day or manually un/plugging it. It's also due to the area lighting sometimes going out during a brownout.

Those removable tab ones actually had a feature lost in the newer up-down timer where you could have multiple on or off...say if you turn the light back on manually it could turn off a second time later. That is why I now prefer digital timers (or smart plugs). Also digital ones have less power consumption.

For the second timer that can be programmed by inserting or removing tabs, spare tabs just need to be put next to take that you're already inserted. Put the spare "on" tab next to the "on" tab that actuates the timer. Do the same with the "off" tabs. That way the spare tabs will simply pass without changing the state of the timer.

With the second timer, and the removable tabs, you stored the extra tabs in the appropriate place within the On or Off zone. They would not affect the timing, as the On tabs would be next to each other, and thus only the first On tab would have an effect.

Loved it !!! thank you for producing consistent format of great information in a clear presentation , without wedging politics into your rhetoric.... at least not that I've been distracted by !!! :)

A bigger cousin to these would be older mechanical traffic controllers. They have a timer that rotates continuously and has tabs set at various places to adjust the percentage of time for a given indication. The actual sequence of lights is controlled by the cam, which is stepped each time a timer tab trips the switch. Thus with two systems, the timer and the cam, you have a unit that can control in what order the lights go and for how long each step is. Acme School has an episode on them, but it would be neat to see you do your take on them as well since you have the traffic modules in the back wall display.

My grandparents have the second timer shown, and I see it lying around every time I visit them, but never investigated its inner workings. So cool!

2 things of note for the mechanical/analogue timers. The first is that they are generally a lot cheaper than the digital ones. The second is that they are not silent. That little motor makes a buzzing sound, regardless of whether the timer is "on" or "off." So you may not want to use one in some situations. Such as your favourite place to read, or your bedroom.

Great info. How about a three part series on the evolution of the door stop and how unappreciated it is.

I've always loved these things. My parents used them to make sure the house growing up was always lit when we were coming home from dinner or what have you. For the models with tabs, they'd just add place all of the like tabs together if they didn't need more than one program. Only the first tab would have an effect, and then the replacements were right there on the face of the dial if you needed them.

Neat teardown, I'm liking "November in January"! I once built a few "industrial grade" electromechanical timer units for a client who owned a quality control company. They tested fabric samples (among a variety of other things) for parameters like durability, colourfastness, and resistance to colour fade in strong sunlight which was simulated by exposing samples to a bank of powerful UV lamps for a calculated period of time. They were using typical off-the-hardware-store-shelf electromechanical timers for the lamps as Alec demonstrates here, but they kept failing as the high inrush current of the lamp ballasts exceeded the switch contact rating in these consumer-grade units... they would arc every time they switched on and eventually weld themselves closed, even though the steady-state current draw was only about 6A per unit (well below the 10A @ 240V nominal rating which is standard for consumer power outlets and switching hardware here in Australia). I couldn't do anything to limit the inrush current to the ballasts because then the lamps wouldn't strike and could possibly sustain damage or have a reduced lifespan, and these lamps were _expensive_ , like "replacement lamp for your high-end home theatre projector" type of money. So I sourced some "Heavy Duty" electromechanical timer modules from Farnell (now Element14) which had a peak rating of 16A for the switch contacts and a nominal rating of 12A. They were of the type that feature two concentric rings of closely-spaced holes on the timer dial - one for On times and the other for Off times - which accept metal pins to set the program. The closeness of the hole spacing allowed for control of on/off intervals down to 5 minutes i.e. 12 divisions per hour in each of the "On" and "Off" rings, which suited the application perfectly. There was a very simple "pin sliding in slot" type of flush-mounted manual override switch on the side of the unit, and nice chonky screw terminals for the mains wiring. They were not cheap. The programming pins were incredibly easy to lose (even though there were a few additional holes on the face of the unit to store unused pins) and they were a bit fiddly to use when setting timing intervals but apart from that it was a pretty solid design, and in this application we were only interested in a few specific time periods so it was a set-and-forget kind of deal. Installed them in grounded metal enclosures into which I fitted heavy-duty mains input/switched output sockets and a suitably rated fuseholder + slow-blow fuse. As far as I'm aware, they were still working fine when he eventually wrapped up the company in the 2010s about a decade after I supplied them, and would probably have gone on for another couple of decades with no issues. There's something to be said for the reliability of the good ol' geared-synchronous-motor-just-flipping-a-switch design. :)

I hope you do a video on electronic pocket dictionaries and spell checkers one day, those were so neat. Love your channel!

I've got a mechanical timer on my boiler which controls when the central heating goes on and off It's like little slider things that pivot so the inside is off and the outside is on. It's got a slider for always on and always off as well Super handy once you find a copy of the manual on the internet to find out what each position of each thing does what!

Now you need a follow up video on the heavy duty timers like used with electric water heaters and how they differ from the wall receptacle mechanical timers.

When I had a car with a block heater, I had one of these set up to start the heater some time before I needed to leave. Helped immensely when it was -30 Freedom units out one morning.

We got one of these for our apartment block's lights. I change it every couple months so that it keeps up with sunrise and sunset times. The pins are completely removable, And by far the most annoying part is bumping the one-way mechanism so you have to go allllll the way around to make the time accurate again.