nilclass

joined 1 year ago
[–] nilclass@discuss.tchncs.de 4 points 2 days ago (4 children)

ISS, as in: you get shot into space?

[–] nilclass@discuss.tchncs.de 34 points 1 week ago (6 children)

Oh, so they can't get autonomous driving to work, thus the next step is to get people who are sleeping to steer the cars remotely

[–] nilclass@discuss.tchncs.de 2 points 1 week ago

Based on the pictures I’d expect the consistency to be rather soft and a bit like gummy.

that's correct. The outer crust is a bit harder than the center, and the center consists of layers, which come apart easily when cutting. Not sure how to recreate those...

Thanks for the other tips, I'll try adding starch next time I experiment with saitan. Also haven't tried to microwave it yet, usually I steam it or bake it.

[–] nilclass@discuss.tchncs.de 6 points 1 week ago (3 children)

Ah yes, that's the one! Thank you so much, maybe now that I know the manufacturer i can find it somewhere.

I've checked multiple asia stores already, will continue doing so.

Regarding making it myself: the ingredients aren' t special, but the texture is something i don't know how to recreate

[–] nilclass@discuss.tchncs.de 1 points 1 week ago

Great, good luck with that :)

Another thing that comes to mind: for audio purposes another technique used in ring modulators for audio effects is to use a mosfet switch to mix the signal with a square wave. This has more byproducts than mixing with a pure sine, but is a lot easier to do. Since you are downconcerting, it should not matter at all if you use a square wave, since the byproducts will all be (higher-order) harmonics of the local oscillator, which you'll filter out anyway.

 

Unfortunately I cannot find it anywhere online. It doesn't help that there is no brand name on it ;)

EDIT: The product is http://milebv.eu/index.php/products/product/25 (thanks to @rbn@sopuli.xyz for finding it!)

I used to buy this at a local vegan store (veganz at Warschauerstr in Berlin), but that store closed a while ago.

It was the most amazing mock duck I've had, but now I can't find it anywhere else. All I have is this picture (I don't even remember why I took it, probably to tell someone how amazing it is).

As far as I recall the product was made in Taiwan, not sure if that helps.

Of course, any other suggestions for tasty mock duck are welcome too, since I just love this stuff 😋

[–] nilclass@discuss.tchncs.de 3 points 1 week ago (2 children)

I'm not sure I understand what you are trying to do... do you want to build a radio? Or are all your signals in the audio range?

Anyway:

Regarding Gilbert cells, the two popular chips are MC1496 and SA631. The 631 comes with a built-in oscillator, so it's quite handy. Unfortunately both are hard to come by these days.

[–] nilclass@discuss.tchncs.de 36 points 2 weeks ago (7 children)

Does this mean jd vance is a centipede?

[–] nilclass@discuss.tchncs.de 19 points 3 weeks ago

Sounds great, except i think this whole thing is about some punching game.. Not sure though, i'm not a sports person

[–] nilclass@discuss.tchncs.de 1 points 4 weeks ago

Damn, i was hoping for them to make it slower!

[–] nilclass@discuss.tchncs.de 1 points 1 month ago

Growing plants with LEDs certainly works, I'm just wondering if the power of a USB port is enough

[–] nilclass@discuss.tchncs.de 1 points 1 month ago (2 children)

there's no need for relays if you have low voltage

That's a good point. Also makes me wonder if those lights will actually make a difference when it comes to plant growth, given the low power.

[–] nilclass@discuss.tchncs.de 6 points 1 month ago (2 children)

It's not completely stupid. One pissible issue: when the light level is around the threshold, slight variations (think: cloud passing by) will cause the relay to switch back and forth quickly. This can be solved with some additional parts (keyword: hysteresis).

I would recommend using a microcontroller, it makes this problem easy to solve, plus you can have more logic to trigger the lights (eg time based).

Another thing is turning off: if it's purely based on light level, you need to make sure the sensor does not "see" any of the LED light, otherwise it thinks the sun is back up

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help (discuss.tchncs.de)
 

I can't recall a time when I wasn't lost in the inner solar system. Currently I'm stuck on the third dot - how do I proceed?

Alt


The picture shows today's XKCD comic.

Transcript:

[A grayed-out sentence in the Times New Roman font reads "Optimistic aliens measure space typographically". The "O" in "Optimistic" is dark black and indicated as representing the Sun (not to scale). The dots of the letters "i" in the sentence are similarly dark black. The dot in the first "i" in "Optimistic" is indicated as representing Mercury; the dot in the second "i" represents Venus; the dot in the third "i" represents Earth. The dot in the "i" in "aliens" is indicated as representing Mars. The dot in the "i" in "typographically" is indicated as representing Jupiter. A measurement bar indicates that the distance between the "O" and the third "i" in "Optimistic" is equivalent to 1 AU (astronomical unit).]

[Caption below the panel:] 
Space tip: if you're ever lost in the inner Solar System, you can just type out the phrase "Optimistic aliens measure space typographically" in Times New Roman and use the dots as a map.

 

I am powering a 5V microcontroller (arduino clone, atmega328p) using a 9V block and a buck converter. Now I want to let the microcontroller occasionally measure the battery voltage, so I can get an idea of how full it is.

My first idea was to use a simple voltage divider:

I've chosen the resistor values so that:

  • the voltage at the measure output is < 1.1V, to be able to use the 1.1V internal reference of the atmega's ADC
  • R1 || R2 < 10kΩ, since the atmega datasheet says "The ADC is optimized for analog signals with an output impedance of approximately 10 kΩ or less"

This is great and all, but what bothers me is that this circuit will constantly draw ~100µA from the battery.

So, my next thought was to add a mosfet to the divider, to switch it on only while measuring:

This is obviously bad, because now when the mosfet is off, the ADC input sees the whole battery voltage.

To address that issue, I've added a second mosfet into the measure path:

This works, and it does not draw any current, except while measuring.

However, it's quite a few parts. So I'm curious if anyone has an idea how to do this with just a single mosfet. It seems to me like it should be possible, but I haven't figured out how.

Oh, and if I'm doing something stupid here, please tell me :)

 

I have a whole bunch of them. They are possibly a bit older (70s, 80s) judging by other contents of the junk box they are from.

There are no labels of any kind, but on the top they have stripes that look hand painted.

For at least some of them the resistance roughly corresponds to the color code.

So, I'm just curious why I can't find anything about these on the internet.

 
 

I'm taking apart a broken tape recorder produced in the 70s (a Tesla B57, made in Czechoslovakia), to harvest some parts (inductors, switches, ...) and maybe reuse the case for some project.

Which made me wonder: are there any dangers to protect myself against? I know about lead, so I'll take precautions when desoldering things. Is there anything else to be aware of? Some fumes, other toxic materials, ...?

I'm not planning to connect the device to power in any way, so from an electrical perspective there should be nothing to worry about (except for caps maybe). Am I wrong?

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