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How a car cigarette lighter works, in CT scans

lumafield.com

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Re: How a car cigarette lighter works, in CT scans

#11

Post by kube-system »

mrguyorama wrote: post #9
kube-system wrote: post #3

Earlier quoted context omitted.

When all you are is a hammer manufacturer, all your demos look like nails.

In which case the question gets inverted: Why of all common things you could CT scan and show people, you choose something that is kinda obvious to anyone who has thought about it for five seconds? I don't think average people struggle to understand the concept of "electricity makes wire hot", especially if they lived at the same time as normal car cigarette lighter usage.

Lumafield posts tons of these. I don't think the average person has thought at all about how these work, and even if they do, the appeal of these is to look at the pretty pictures (and demonstrate the analysis that is possible non-destructively to their target audience), not to understand "electricity makes wire hot".

They have a scan of a dang football, and it isn't because people don't know there's air inside: https://www.lumafield.com/article/ct-big-game-football

Re: How a car cigarette lighter works, in CT scans

#12

Post by peterleiser »

beaglesss wrote: post #6
Arainach wrote: post #2

It's a cool explanation, but I'm not sure what a CT scan offers that cutting it in half with a bandsaw wouldn't.

IR heat profile might have been cool. It's a shame cars don't come with them anymore. A lighter can save someone's life and cost next to nothing. You can toss a lighter in but something about the designated electric plug is pleasing and invites you not to lose it.

Yes, very handy even for non-smokers. We have a 2015 vehicle that we bought used that came with a cigarette lighter. I removed it and put it in the glove box.

Re: How a car cigarette lighter works, in CT scans

#13

Post by ofalkaed »

gwbas1c wrote: post #5

> this design, developed in the 1950s, is entirely analog Uhm, how is this analog? Perhaps "electro-mechanical?" Is there such a thing as a "digital cigarette lighter?" It's not like the electric circuit is an analog of the act of lighting a cigarette; as opposed to what we commonly use the word "analog" to mean that something in the system is an analog to what's being recorded or processed. (IE, in analog tape the m…

It is an analog of a traditional burning fuel lighter. But they are using analog to refer to the fact it relies completely on analog circuitry and I suspect they actually wanted to point out the fact that it is 100% passive circuitry relying solely on the electrical and physical properties of a resistor (the coil) which is the interesting thing here, the resistor is its own temperature sensor. They sort of explain this and walk you through it all, probably trying to stick to language suited to their audience.

Re: How a car cigarette lighter works, in CT scans

#15

Post by floatrock »

Arainach wrote: post #2

It's a cool explanation, but I'm not sure what a CT scan offers that cutting it in half with a bandsaw wouldn't.

Same reason every coding tutorial -- no matter the capabilities of the language -- starts with a simple "hello world".

Learn with a simple toy example before moving onto the industrial-grade deconstruction that really shows the power of the tool. These guys have done CT scans of things like real vs. fake airPods and charger bricks to show what really justifies their (probably) 7 or 8-figure price tags.

This one is just content marketing of something anyone can wrap their head around.

Re: How a car cigarette lighter works, in CT scans

#16

Post by ssl-3 »

mrguyorama wrote: post #9
kube-system wrote: post #3

Earlier quoted context omitted.

When all you are is a hammer manufacturer, all your demos look like nails.

In which case the question gets inverted: Why of all common things you could CT scan and show people, you choose something that is kinda obvious to anyone who has thought about it for five seconds? I don't think average people struggle to understand the concept of "electricity makes wire hot", especially if they lived at the same time as normal car cigarette lighter usage.

Those who have thought about it for more than five seconds understand that there is more going on inside of a normal car cigarette lighter than "electricity makes wires hot."

Re: How a car cigarette lighter works, in CT scans

#17

Post by wumms »

> You might think such a system would involve a thermostat, a microcontroller, and an actuator, but this design [...] has bimetallic arms with steel on the outer surface and copper on the inner surface. As the filament heats up, the arms warm up, causing the copper to expand faster than the steel. This expansion pushes the arms open, releasing the lighter. The coil spring then causes the handle to pop out, signaling that the lighter is ready.

Maybe I am in a picky mood, but for me the intro made it sound like all three items (thermostat, microcontroller, actuator) would not be necessary, though of course only the microprocessor is missing from the design (thermostat -> bimetallic arms, actuator -> spring).

Mandatory link to another marvel in the same problem space (I found the 19min video worth the time):

"An Antique Toaster That's Better Than Today’s [video]"

https://www.youtube.com/watch?v=1OfxlSG6q5Y

https://news.ycombinator.com/item?id=21164014 [2019, 386 points|5 years ago|232 comments]

Re: How a car cigarette lighter works, in CT scans

#18

Post by 1970-01-01 »

wumms wrote: post #17

> You might think such a system would involve a thermostat, a microcontroller, and an actuator, but this design [...] has bimetallic arms with steel on the outer surface and copper on the inner surface. As the filament heats up, the arms warm up, causing the copper to expand faster than the steel. This expansion pushes the arms open, releasing the lighter. The coil spring then causes the handle to pop out, signaling…

No, you have the correct take. The bimetallic bond is a thermostat. The spring is an actuator.

Re: How a car cigarette lighter works, in CT scans

#19

Post by gwbas1c »

ofalkaed wrote: post #13
gwbas1c wrote: post #5

> this design, developed in the 1950s, is entirely analog Uhm, how is this analog? Perhaps "electro-mechanical?" Is there such a thing as a "digital cigarette lighter?" It's not like the electric circuit is an analog of the act of lighting a cigarette; as opposed to what we commonly use the word "analog" to mean that something in the system is an analog to what's being recorded or processed. (IE, in analog tape the m…

It is an analog of a traditional burning fuel lighter. But they are using analog to refer to the fact it relies completely on analog circuitry and I suspect they actually wanted to point out the fact that it is 100% passive circuitry relying solely on the electrical and physical properties of a resistor (the coil) which is the interesting thing here, the resistor is its own temperature sensor. They sort of explain th…

> it relies completely on analog circuitry

A resistor is not "analog circuitry"

> the resistor is its own temperature sensor

No, the clasp that holds the spring down is a bi-metallic strip that bends when it reaches a temperature. This is not "analog" because there is nothing for it to represent.

The article is merely a case of calling something old "analog" without knowing what the word means.

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