87
votes
Are toasters really electrified inside of the "slots"?
I have actually stuck a knife into a toaster, and I can confirm that yes, it is very definitely electrified. Please, Please, Please, don't do this. The only reason I'm still alive is because of a good ...
- 806
60
votes
Are toasters really electrified inside of the "slots"?
The toaster is going to have heating elements of a type of wire that has very high resistance, usually nichrome wire. When electricity is applied to the wire, it becomes hot enough to toast bread.
You'...
- 6,940
43
votes
Accepted
How did mechanical engineers work before SolidWorks?
At the beginning of my career (1979) as a design engineer at HP, the mechanical engineer created the part design and then rendered it in pencil on paper, and then transferred it onto sheets of vellum ...
- 14.3k
41
votes
Why does the manual to a 1989 TV almost dedicate a page to the "pin assignment" of the SCART connector?
There was no Internet then. The only source of most of that information was through the manuals and if it wasn't published you could be stuck. Many of us made up adaptors and cables and this ...
- 10.3k
27
votes
What would "wired houses" refer to in 1928?
See this article: Digital History: The Rise of Hollywood and the Arrival of Sound.
It refers repeatedly to "movie houses", and uses the term "wired for sound". these are certainly ...
- 7,726
17
votes
How did mechanical engineers work before SolidWorks?
In the offices I worked in, drafters were also expected to have a grasp of the trades required to build the thing they were drawing. They'd have some background in welding, fitting, and fabrication. ...
- 271
14
votes
What would "wired houses" refer to in 1928?
they mean wired for sound. Previously movies were accompanied by a pianist or organ player.
- 6,534
13
votes
Why aren't screens round instead of rectangular?
The earliest CRT displays were in fact round. However, that was more due to manufacturing tradeoffs of making large glass envelopes with vacuum inside than a desire for the display area to be round.
...
- 11.4k
13
votes
Are toasters really electrified inside of the "slots"?
How could they possibly sell a consumer-oriented product like that which zaps its users if they happen to touch the interior slightly as they stick a knife into the piece of toast bread to get it out ...
10
votes
Accepted
In a reinforced concrete detail drawing what does 'reinforcement to be GK 60' mean?
Check this book out; it seems to be talking about that particular grade of steel used for reinforcement.
The choice of main bonded reinforcement is based on its high tensile strength and interaction ...
- 367
10
votes
Are toasters really electrified inside of the "slots"?
Why would they have the metal parts responsible for pressing against the bread and keep it in place be having electricity going through it?
They don't. The metal parts responsible for pressing ...
- 633
6
votes
Are toasters really electrified inside of the "slots"?
Yes, and no. When the toaster is actually toasting, then obviously there's electricity running through the elements, which need to get hot (and will be seen to glow). Once it's turned off, but still ...
- 209
5
votes
Would not a telephone call (from the late 1950s) auto-disconnect if one of the parties "closes the handle"?
If you could truly indefinitely keep a line open for anyone who calls you, by simply not hanging up on your end, the potential for abuse is endless.
That's the way the POTS (plain old telephone ...
- 10.3k
5
votes
Are toasters really electrified inside of the "slots"?
A toaster is simply a length of nichrome wire put across the mains power, which will be 120 or 240 VAC, depending on your country:
Those red-hot wires you see in the toaster? That's the nichrome wire....
- 161
5
votes
How did mechanical engineers work before SolidWorks?
I think the duties that engineers have to perform are independent of the tools they use. Nowadays there seems to be a trend that everybody involved in a working process, regardless of if we are ...
- 153
5
votes
How did mechanical engineers work before SolidWorks?
But I am left with a question I don't have the answer to, nor the resources to answer it. These days it seems most mechanical engineers (at least the ones I know) are really performing the role of ...
- 24.3k
5
votes
Is it dangerous for a child (or anyone) to bang away with a hammer and unscrew an old clothes washing machine?
the washing machine does not contain any energy storage capacitors which would retain a lethal charge for days after being unplugged. In addition, there's no pressure or vacuum chamber inside the ...
- 14.3k
4
votes
How did Al-jazary's "castle clock" work?
There is an excellent description of the castle clock in this article on muslimheritage.com. It describes the full workings of the clock, including all of the mechanisms for things such as doors ...
- 6,386
4
votes
Accepted
What were the technical reasons for type bar designs being more common than type wheels for manual typewriters?
The reason turns out to be that type bar typewriters are faster. A type wheel is much heavier than a single type bar and needs to both rotate and move forward, so operating it with a finger requires ...
- 254
4
votes
If the Roman number system was so bad, how did the Romans build all that relative high-tech?
What makes you think the ancient Romans did scientific or engineering analysis or used any form of mathematical analysis? Most of the mathematics currently used by engineers was developed much later - ...
- 9,642
4
votes
Why would a "delayed loudspeaker" be so expensive in the 1970s?
The band was the Grateful Dead and the invention necessary was an analog delay line that was inserted between the main audio mix signal line and the power amps that drove the speaker arrays (which ...
- 14.3k
4
votes
Accepted
Why aren't these spokes radial?
Radial lacing "tortures" the spokes of the wheel because when torque needs to be transferred from the hub to the ring when accelerating (or from ther ring to the hub during braking).
Radial ...
- 24.3k
3
votes
Are toasters really electrified inside of the "slots"?
Inside the toaster is a special type of wire, usually a nickel-chromium (Nichrome) alloy, that has a high resistance and lasts reasonably long at glowing-orange temperatures. It will be mounted on ...
- 131
3
votes
Accepted
Why were pneumatic thermostats commonly installed in buildings?
In the 1940's and 50's, dynamic system controllers were invented which used air pressure to work. It was possible in fact to design and build not only analog control mechanisms but also binary logic ...
- 14.3k
3
votes
How is it possible that an *undertaker* invented the automatic telephone exchange? And as early as in 1888?
You may be misunderstanding what "undertakers" actually did in this time period. Even in the 1950s in the UK when I was growing up, in rural areas the local undertaker not only did the carpentry and ...
- 12.5k
3
votes
Accepted
WW2 technology - How was this on-screen frame counter added to old film-media footage?
If you right click on the YouTube video and set the playback speed to the minimum, if is obvious that the video has been converted from 24 FPS cine film to 30 FPS video for TV broadcasting. Every ...
- 12.5k
3
votes
When were airfoil cross-sections first used in turbine blades?
Good description in the link, but curved surfaces were in use as sails around 800 years ago and Bernoulli came up with his formula , Ludwig Prandtl was testing sections in 1017 in his large wind ...
- 15.5k
3
votes
Why aren't screens round instead of rectangular?
X-Y addressing and raster scanning are both much simpler when addressing a rectangular area. So either you need to lose (waste) the corners or adopt a fundamentally different addressing scheme.
...
- 1,620
3
votes
Why do we pave roads instead of making them from removable parts?
Other answers have well described a road is a lot more than just the surface layer and the vast majority of the cost is the planning and logistics involved rather than the actual materials.
Current ...
- 15.2k
3
votes
Are toasters really electrified inside of the "slots"?
I just to want to add a caveat here for people reading this who might read these answers and think the advice applies to all electrical devices. For a toaster, sure, turning if off and removing the ...
- 131
Only top scored, non community-wiki answers of a minimum length are eligible