Wikipedia:Reference desk/Archives/Science/2016 June 29

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June 29

telepathic technology

I remember reading in 2001–2005 about researchers designing technology that would allow drivers to manipulate automobiles through a helmet. Do we have an encyclopaedic article on this? --Romanophile (talk) 02:59, 29 June 2016 (UTC)

Well the general principle is brain-computer interface that might get you started. Vespine (talk) 03:12, 29 June 2016 (UTC)

Hovering your cursor over the title of this section gives the answer. AllBestFaith (talk) 13:11, 29 June 2016 (UTC)

It's not really telepathic, of course, or even Telepathy (software), though it might appear magical to those who don't understand it. Dbfirs 16:47, 29 June 2016 (UTC)

I wouldn't say that's strictly speaking true. At this point, the technology, though cutting edge, is many orders of complexity below sending any kind of information that might be mutually intelligible between brains, even motor or sensory data. The most advanced experiments in this vein have implanted an electrode mesh in the brain of paraplegics, which then can (with a little training) be used to act out volitional commands with a mechanical appendage. Pretty impressive in its own right, but a far cry from sending information from one brain to another in any format that would have any kind of use. And indeed, there would be huge ethical implications for implanting a device that could stimulate neurons rather than simply receive their signals. All of that said, this technology could be adapted to that purposes, in principle; the major roadblock is not the transmission, its the encoding and decoding of brain signals which we still have only a very basic understanding of.

All of which is a long-winded way of getting to this point: if these not-insignificant obstacles are overcome (and they are the focus of a massive amount of research now), then, in principle, that would qualify as telepathy, I dare say. Telepathy as a concept might have its origins in mysticism, but I think a lot of people who have (gullibly) believed in telepathy in contemporary times have often figured it had some kind of (unknown) scientific explanation, as with "parapsychologists"/enthusiasts who are proponents of the existence of "ESP"). Interestingly, though, we might not be all that far off from a time when that's actually the case--that there will be a technological mechanism for actual brain-to-brain communication that does not use external sensory channels. Snow ^{let's rap} 10:29, 30 June 2016 (UTC)

HT1621: seven segments LCD driver Power Consumption

I'm trying to find out the power consumption of, HT1621, a LCD driver. This page says[1]:

   Power Consumption:
   <3mA (@5V)
   <600μA (@5V with no load, LCD on, internal RC oscillator on)

I'm not sure exactly what "no load, LCD on" means. If the LCD is on, then wouldn't that make it the "load"? The "load" for a LCD driver would be referring to the LCD, right? Johnson&Johnson&Son (talk) 05:07, 29 June 2016 (UTC)

For the the LCD to work it needs to be "powered on" even when it is not 'displaying' anything. I assume "no load" means nothing actually being displayed. Notice there's a LOT MORE to the display than just the segments (quite unlike a seven segment LED display) Vespine (talk) 07:00, 29 June 2016 (UTC)

There is? I thought it's just the segments and nothing more. Sometimes there's a backlight, but that's not common.Johnson&Johnson&Son (talk) 08:42, 29 June 2016 (UTC)

See Liquid-crystal display for an explanation of how LCDs work. Unlike with LEDs, they're not simply a segment that is turned on and off. Nil Einne (talk)

My question is about a segment LCD driver driving a segmented LCD display though. Looking at its schematic I don't see anything in the display besides the individual segments. Johnson&Johnson&Son (talk) 12:47, 29 June 2016 (UTC)

The HT1621 in addition to driving a 32x4 LCD has a bidirectional serial data interface and tone generator outputs. It will draw an unspecified extra current if these outputs are loaded. AllBestFaith (talk) 13:07, 29 June 2016 (UTC)

Right, but that this is about why the display needs power in general and that relates to how LCDs work. The article I linked to does discuss segmented displays, I checked before I linked it. Not in great detail but segmented LCDs aren't some weird special thing anyway, they're still LCDs with similarities to oher LCDs, although they are often reflective rather than transmissive that many other LCDs are. As mentioned above, the driver itself has several other features. (Of course the fact you have a driver means it'll need power.) Nil Einne (talk) 15:57, 29 June 2016 (UTC)

LCD ON refers to the internal state of the chip that it enters after you issue the LCD ON command, not to the LCD as such. "No load" likely means that the figure was measured with all output pins disconnected (incl. those that connect to the LCD.) Asmrulz (talk) 21:01, 29 June 2016 (UTC)

Looking at its schematic I don't see anything in the display besides the individual segments. What schematic are you looking at? Are you confusing the LCD Display with the LCD Display DRIVER? Have you seen the datasheet ? Specifically the block diagram might help here. There's no actual display in the HT1621, you have to plug a display into it. Vespine (talk) 22:28, 29 June 2016 (UTC)

The HT1621 is a MOS device, with internal or external oscillator in kHz range. MOS usually is shotcut protected by itself. A LCD segment can be seen as a capacitor with leakage about 50 MΩ. I guess, the data sheets describes basics of the device of origin and other use. So anything the low power device is beeing used for, the designer should be able to precalculate the power consumption of the whole application.--Hans Haase (有问题吗) 09:49, 3 July 2016 (UTC)

Identify these mushrooms

Hello

Please can you help me identify these mushrooms. Many thanks for your time. 163.28.80.40 (talk) 15:28, 29 June 2016 (UTC)

Sorry I can't tell you the answer, but I can tell you that Reddit's mycology page [2] has far more mushroom-expert readers than we do. So if you don't get a good ID here, I'd try there. SemanticMantis (talk) 15:31, 29 June 2016 (UTC)

FYI, my antivirus software has blocked that image as potentially dangerous. User discretion is advised. Rojomoke (talk) 21:51, 29 June 2016 (UTC)

I don't know what happened with your antivirus software, but the file is fine, so I'm uncollapsing the thread. -- BenRG (talk) 04:38, 30 June 2016 (UTC)