"A proper microwave designer would know that the best position to get something out of the microwave is how it was put in, and take care that regardless of microwaving time, the turntable would always stop in the position it started."
Turns out, it was just that it did a complete turnaround on a time segment (5 seconds) and it was easiest to input time in 5 second intervals.
Still, good, if not great design.
Why? Because there is an also very important requirement: when the user wants to get his stuff out let him do it immediately: do not waste his time. This way they did not compromise this important requirement while gave a solution to the other problem as well.
(Well, maybe it is me who is funny, I don't know.)
A later comment points out a microwave that does this (also the one ricardobeat mentioned):
»My 1990’s Sanyo Microwave has a “boomerang turntable”, meaning the turntable always returns to its starting point. It turns for a few seconds after the oven stops, until a micro-switch, driven by a cam on the shaft, is tripped.
The period or revolution happens to be exactly 12 seconds. (Has a synchronous motor?) I know this because any multiple of 12 seconds means the turntable stops immediately.«
I have been interested in the subject ever since I read the part of Code Complete dealing with the notion of abstraction.
If everytime you woke you had to think about the fact that a door is a bunch of atoms that together form different materials but together some of it being the doorknob you'd never be able to leave your bedroom.
It ties closely with the notion of affordance
A teacher told me that the reason for the banning of pork in the Quran and the Bible is to prevent some diseases. Straigth up banning pork for health reason solved the problem. It's probably some kind of myth.
If you are really impatient, and don't want to wait for the turntable to finish moving, the period of revolution is 12 seconds. Programming in multiples of 12s means the item is ready to remove as soon as the beeper goes off.
Appliance manufacturers go for the cheapest parts possible that still perform reliably under the warranty period. The motor driving that turntable is not a precision stepper or brushless motor with variable microprocessor speed control. It's a cheap A/C motor (perhaps with a drive belt for torque) that's switched to line current by a 30-cent mechanical relay. You can tell it's A/C when the turntable starts in a random direction each time it's energized.
There is no need to put an expensive polarity-reversal circuit (with mechanical or electronic memory) in the assembly just to alternate the turntable direction. The cooking effect is the same.
Given that the period of my oven is bang on 12 seconds, averaged over many revolutions, I think it's probably a synchronous motor.
The other thing to remember is that in the 1990s a microwave oven cost several hundred dollars at least. Now you can pick one up for fifty bucks, possibly forty. Losing extraneous features like "boomerang turntable" is presumably part of how the manufacturers managed to respond to the downwards price pressure.
You can find them in stores here, but they're not popular. I've told several people about them, and they were just as delightfully surprised as I was.
Go somewhere with 240V and two things happen: (a) you're far more likely to die of electrocution in your own house and (b) you can get a decent tea kettle.
At 110v you would be looking at 27 Amps which may be a little high. I had not thought this one through before, thanks.
The maximum current determines how thick the wires have to be. Since power (ability to heat or do other work in one unit of time) == current * voltage, doubling the voltage doubles the amount of power a wire of a given thickness can deliver.
Looks like the maximum power that a US kettle can produce is 110 * 20 = 2200 watts, so will take about 3000 * 2200 = 1.36 or 36% longer than an EU kettle to boil.
Microwaves make more sense in that scenario
They're also frequently mounted overhead, where it's more dangerous to retrieve a mug or big Pyrex cup. Contrast that with the kettle which has that little flap over the spout and is spill resistant.
The time it takes to boil the water is about the same amount of time it takes for me to grind my coffee beans and set up the Aeropress, so it works out.
So curious... what sounds so ridiculous about it? It seems so natural and obvious for me...
I find using a microwave to boil water so... strange and unnatural. I'm not sure why, but its just odd. That's what a kettle is for!
To quote a song: "You could not feel sadness if you've never tasted joy" - perhaps, if he's content with his tea bags, we can let him drink his tea bags. Since switching, I can tell you first hand, that I can no longer drink tea bags, or even poorly steeped teas without cringing. I sound like an asshole, I know.
That being said, I love me my loose tea leaves, but it's just a different product then bagged tea, one hasn't ruined the other.
Japan in general is a great example for optimizing people's daily lives without compromising on quality. There are many of such rituals to explore that are very specific to that country.
It is a somewhat interesting philosophical question of whether or not it's worth it to try something better if it might affect what you already enjoy.
This is the second apartment I've lived in without a microwave, and I think I've missed it all of twice. Once, when I wanted some popcorn, and a second time when I was in a hurry to heat something up.
Don't get me wrong, if it was just for my lunch, I'd use the microwave, but if I was plating something for family dinner, I'd use the oven.
Plus, I mean, look at this kettle and tell me you don't want it: http://www.etsy.com/listing/97984435/retro-80s-seibel-bubble...
A distinct advantage of electric kettles over stovetop kettles is precise temperature control. High-end loose-leaf white and green tea wants 70c-82c water; Aeropress coffee wants 80c-90c.
Speed is obviously another benefit. Good electric kettles are significantly faster than stovetop kettles.
Also, electric kettles take up counter space, but stovetop kettles take up space on your cooktop. Space is more constrained on the cooktop; you probably only have 4 burners, and on my stove, if the front two burners have skillets on them, it's awfully hard to maneuver with the rear burners.
Also, I hate the ergonomics of cutesy round tea kettles, and, obviously, that's a tea kettle: most electric kettles hold more water.
I didn't realize electric kettles could control water temperature. Which one do you have? I've always just boiled water, and then let the temperature fall to where I want it, even when using an electric kettle.
Also, for me, the fact that the regular kettle is on the stovetop is actually better, because that space is almost never in use (only during cooking), and when I do need, I can temporarily shift the kettle elsewhere. My counter space, on the other hand, is always at a premium (I only have 2 squares.)
While a few companies like Mighty Leaf do offer higher quality, whole-leaf tea in bags (or rather, sachets), at that point you're paying as much as a 2x-3x premium over loose-leaf tea of comparable quality. For example, this tea from Adagio is about 16¢ per cup loose-leaf, but 40¢ per bag: http://www.adagio.com/black/ceylon_sonata.html
I'd suggest anyone who likes tea get a stainless steel mesh infuser (they're about $10) and go loose-leaf. It's worth it.
So the best advice I can give to an American arriving in England is this: Go to Marks and Spencer and buy a packet of Earl Grey tea. Go back to where you’re staying and boil a kettle of water. While it is coming to the boil, open the sealed packet and sniff. Careful---you may feel a bit dizzy, but this is in fact perfectly legal. When the kettle has boiled, pour a little of it into a teapot, swirl it around, and tip it out again. Put a couple (or three, depending on the size of the pot) of tea bags into the pot. (If I was really trying to lead you into the paths of righteousness, I would tell you to use free leaves rather than bags, but let’s just take this in easy stages.) Bring the kettle back up to the boil, and then pour the boiling water as quickly as you can into the pot. Let is stand for two or three minutes, and then pour it into a cup.
I don't trust the idea of microwaving water for tea, because microwaved water will probably be sub boiling temperature.
(but in all seriousness interesting article about the problems of not critically addressing things that annoy you)
Lighter teas (white, green, chamomile, etc) are best brewed at 70-80C, so that's not general advice :)
Well, don't worry unless you have a really smooth cup and going for 5-10 minutes or more...
i find this to be an excellent example of (failing at) optimizing for the common case--probably >99% of the interactions people have with microwaves are pure timed-cook-at-100%-power, and requiring an extra button press to enter that mode is silly.
Not sure if one can expect mankind to extend its horizons to the whole world or universe as it really is. The older I get, the more I think of us just being animals at all. This "look beyond your own nose" thing is maybe not so realistic/real for our species, as nice it sounds in theory.
Reminds me of a comic http://questionablecontent.net/view.php?comic=2202
What blocks microwaves is thin metal plate in the door. With holes so you can see inside.
It's a Faraday cage. And if you read specs in the manual, it' says the percentage that it blocks "for sure" to match some regulation. Hint, never close to 100%
And there's a percentage of radiation that goes out, and fry the inpatient that keeps it's face there
(It does happen through the gap between the door and the rest of the microwave, but there's some neat design work to keep it from getting too bad.)
Of course it leaks, though. It leaks so much that when I was working on sensitive RF receivers, I could see when microwaves were turned on for lunch hour in other parts of the building. It's the leakage that makes it interfere with wifi. Don't worry though, you absorb more RF energy through the wifi in your devices and through your cell phone.
I'm fairly sure the holes are sized such that only certain wavelengths can leave, but that could be nonsense.
Of course, you can block/scatter visible light that way, but it's awfully difficult (since the holes would be tiny)