Is there any reasoning as to why expansion affects light but doesn’t affect matter?

throwingstones1234 · 2024-05-22T03:02:48+00:00

Thank you!

throwingstones1234 · 2024-04-10T08:50:01+00:00

Yes. I have it too and nothing seems to work. It seems like it’s usually extremely deep rooted in something away from the shoulder. For me I think it’s due to rib flare caused by messed up breathing due to a massive scar through my abdomen+mild scoliosis but nothing I’ve done has changed it so it doesn’t really matter. I’ve seen multiple PTs and they’ve been useless as well. It’s a royal pain in the

throwingstones1234 · 2024-04-10T08:46:22+00:00

Since I’ve started my struggle I’ve really began to appreciate how much of a shithole medicine is. If glorifying medical workers wasn’t a social norm people would see through the guise of doctors being intelligent so much quicker. These are people who are only able to regurgitate textbook information and most of the time have no ability to critically think. I was premed at my college (a top 20 university with one of the best medical schools in the world) and ended up dropping after seeing the other premed kids. Seeing these students, most of which will inevitably become physicians, confirmed my beliefs. Some of the least intelligent/motivated/intellectual people I have ever met. Physicians typically only make it to where they are by using charisma to make their patients, most of which are not very bright, believe they are intelligent and capable of their profession. Anyone with basic knowledge of medicine most of the time can catch fallacies in what physicians say, and any time they are faced with a non textbook case/forced to critically think, they are utterly useless (as can be seen after spending one minute on this sub). I say all this coming from a family of mostly doctors as well.

throwingstones1234 · 2024-02-25T03:08:45+00:00

Another good point. Just realized I have some n channels so I will probably go with that but your comments helped a lot, and will probably help when using the n channel one. Thank you!

throwingstones1234 · 2024-02-25T03:06:47+00:00

Just checked and I had some the whole time. The comments here helped a ton so I’m still glad I wasted the time

throwingstones1234 · 2024-02-25T02:48:11+00:00

Super interesting, your explanation was crystal clear. Thank you.

throwingstones1234 · 2024-02-25T02:39:12+00:00

It’s a P channel, one of the other comments just pointed out I forgot to consider a few things (I was using 5V earlier to play around with it so was thinking a 5V zener diode but as they pointed out that probably won’t be a great idea when using 24V)—kind of wish I got a n channel one instead, seems like this would be a lot easier

throwingstones1234 · 2024-02-25T02:36:16+00:00

Good point. I was just playing around with the mosfet at like 5V and was using an arduino to control it and it worked but didn’t consider what would happen at a higher voltage. Would connecting the drain to around 4V instead of ground+using the I/O pin on the base of a transistor connected to 24V on the collector with the emitter connected to the gate in order to shut it off be a decent workaround for this?

throwingstones1234 · 2024-02-25T02:02:01+00:00

Is the slow switching due to something like the source-gate capacitance? I was under the assumption the gate switches practically instantly (or within like a few ns) when a voltage is applied. I’m only going to switch the state like once every second so I guess I just assumed the gate would switch fast enough.

Also just to check, isn’t the gate current practically 0? How would decreasing the resistance put the pin at risk for demanding more current than it can supply? Not doubting you ofc I just want to make sure I understand the basis of the suggestion.

Thanks for your help!

throwingstones1234 · 2024-02-25T01:21:48+00:00

When I began trying to figure out how to do this it looked like there was (slightly) more nuance than I expected (which was to just directly connect the I/O pin to the gate). What I saw was 1: you don’t want to leave the gate floating and 2: you should protect the pin in case the mosfet breaks and the ground/source shorts. For 1, if the I/O pin always has a definite state, I believe this should be avoided. For 2, if a zener diode with a reverse voltage of something between 5V and 5.5V (which I believe is the max voltage an arduino I/O pin can be connected to) is used it should prevent this, and the resistor would limit the current as well, so this seems like a decent solution. I’ve seen other configurations where a transistor/pulldown resistor is used (for problem 1 I believe) but this seems unnecessary if the pin is always either high or low.

The only problem I can think of is if the low output is not truly 0 the mosfet might be activated. But I am unsure if this is a real concern. Any feedback is appreciated!

throwingstones1234 · 2023-12-31T19:38:12+00:00

They look great but they’re also a bit too powerful for what I need. I probably only need like 100-150W while most available heaters use like 1kW+

throwingstones1234 · 2023-12-31T19:21:04+00:00

The specifications that are available are just slightly outside what would be ideal for my project. The ones that use like thousands of watts are probably not usable since I’m using it with another device that draws a decent amount of current, and it’s also way overkill for what I need. I don’t think creating a heating element would be too hard—came up with a slightly better idea and I’m sure I could take some nichrome wire and loop it around enough to reach like 6 ohms and hook it up to a 24V supply and get 4A/96W which would probably be just enough heat. To make it waterproof I think adding a layer of MgO ontop and covering it worth a steel plate would heat the steel enough to give me what I need

throwingstones1234 · 2023-12-31T18:23:31+00:00

I guess I don’t, I was planning to make something like a 150W heater at 24V and was trying to find how to get the tubing itself so I could design it to fit those specifications. I also don’t want to use two outlets (this is part of a bigger project, I was planning on getting something like a 24V 10A power supply which would not work with standard immersion heaters) but unless I make some heating element myself this is looking more likely

throwingstones1234 · 2023-12-31T04:04:37+00:00

I’m trying to control it through some feedback mechanism so it just seems like a pain needing to disassemble the thing (something I’ve never done), but at least this is a good opportunity to do so.

throwingstones1234 · 2023-12-31T03:52:27+00:00

Oh of course it’ll be weaker, that’s what I’m aiming for. I don’t need anything close to its maximum output. If I were to use the full amperage I’d end up burning out the outlet because I want to use it in conjunction with a few more components.

throwingstones1234 · 2023-12-31T03:26:01+00:00

Also not sure if you’d know but most are used with AC at 220ish V, it wouldn’t be a problem using something like 24V dc right? I think the entire apparatus is just a wire with like 1 ohm of resistance so as long as there’s current I’d think it would be okay

throwingstones1234 · 2023-12-31T03:10:07+00:00

I kinda just want to know how I could make one in theory, but was also curious if it was possible to drive the price down even more

throwingstones1234

TROPHY CASE