Electrical Engineering

tyblu

1:43 AM

hola @markrages ! How go the holidays?

markrages

1:59 AM

not bad

cgi.ebay.com/… <-- what are the chances this contraption would work?

tyblu

In storage for 15 years, so it may not have cameras for fiducial marks. This thread on AVRFreaks recently discussed the pros and cons of second hand P&P machines.

tyblu

4:03 AM

I just realized, to my horror, that my SanDisk multi-format card reader (XD, SD + varients, CF, CF2) is a low-speed USB 1.0 device: restricted to 183kB/s. I have a 32GB CF2 card. 32 GB / (183 kB/s) > 2 days. LOL. Time to go shopping...

W5VO

wow

that should be criminal

and by the way... 500 rep? wow

tyblu

@W5VO hehe.. go big or go home I guess.

@NickT will just have to make it apparent that all who enter this room are obligated to up-vote it. cough @Kortuk @NickT cough

W5VO

4:20 AM

oh, and by the way, after doing more research - HDMI and DVI-D use TDMS, not LVDS. I thought all you needed was a couple LVDS transceivers and a good SERDES, but boy was I wrong.

tyblu

neat - haven't seen that one before.

W5VO

Xilinx and Lattice have both made a "reference" implementation of HDMI in -> HDMI out, and Lattice's is good up to 1080p @ 60Hz

basically, you get the on-chip PLL to take the byte clock, multiply it by 5, and then shift in/out data using a dual-data-rate shift register at 150MHz

crazy fast

tyblu

4:35 AM

@W5VO they strip the encryption within 5 clock cycles?

W5VO

@tyblu They strip encryption at the byte level

tyblu

oh.. thought it was an obfuscating encryption. Didn't realize it was just part of the packet.

W5VO

what really happens is that you start off with 3 bytes per pixel. This gets translated into 10 bits per byte to help stabilize the number of transitions. The sync clock is a byte sync clock, so it is 1/10th the frequency that the bits should be clocked at.

All the encryption/decryption goo comes before that - the bytes going into the serializer are already encrypted.

The whole FPGA would be working at the same frequency as the byte clock, but the SERDES would be running 5x that frequency, and would be clocking on the positive and negative clock edge.

tyblu

er.. so does it matter that the code is DC balanced, or does that need to be translated back and forth too? 'suppose a decryption key could take it into account, and leave it in 8b/10b format.

W5VO

the 8b->10b conversion maintains DC balance. The 8b input can be arbitrary.

tyblu

4:47 AM

actually, i'll stop talking out of my ass. I don't even know that HDCP uses a key.

W5VO

both the source and the sink have a key, and that's transmitted over a separate line. I think it uses I2C

tyblu

yes, i've used other dc balance encodings before, and looked at other "8b/10b" schemes.

... just not TDMS. So, do you think you'll try out making this widget?

W5VO

Hrm... it should be a very simple board...

I need to do more research into the protocol, and see how much (ballpark) it's going to cost just to have a HDMI through setup. I'm hoping it doesn't need a really expensive part.

W5VO

5:10 AM

wow... maybe I won't be using Lattice's reference design...

Starting price for that FAMILY of FPGA's at Mouser: $75 mouser.com/ProductDetail/Lattice/LFE3-35EA-6FN484C/…

tyblu

Nice.

W5VO

and I don't know how small my design will be - may have to use a 256-pin BGA package.

tyblu

No QFPs available?

W5VO

only for small designs

check out this matrix: xilinx.com/publications/prod_mktg/…

2

Q: Analog Max Frequency Detector Circuit

As a follow up to this question: How to sample audio at Nyquist frequency with MSP430F5438? What type of circuit would I use to generate something that a microcontroller could use to determine the max frequency of an input? I was thinking it would preferably provide a voltage that is lineally re...

frequency-measurement

I wonder if you could do it with two 1st-order RC filters, each feeding a RMS circuit... and measure the difference between RMS(original), RMS(corner @ 1kHz), RMS(corner @ 5khz)...

tyblu

5:27 AM

@W5VO hardly know what I'm looking at.. Whole new world :D

@W5VO yes.. that's basically what I was suggesting by the crossover, 'cept it uses bandpasses. In reality none are practical with today's cheap and fast ADCs.

W5VO

@tyblu it's a very interesting academic exercise, because anyone with sanity would just say "I want/need to sample at X frequency, so give me a Nyquist filter for 0.45 X"

tyblu

yes, I like it.

Nick T

5:08 PM

0

Q: Can you harvest electrical energy from the air?

I found a website recently about harvesting energy from the air, and I am wondering if someone could tell me why the following wouldn't work? Their "generator" is supposed to make electricity from the ionosphere. Some claim it can knock out your electric bill totally (a bigger version, not this ...

power

needs new "scam-science" tag :P

tyblu

hehe -- I just saw it. Finally get to take that retarded circuit apart :D

it certainly does need something like that.

Nick T

6:45 PM

0

Q: Internal threading fix for Sony Bravia

I recently got a Sony BRAVIA 46". When I was mounting to an existing mount, I used the requested machine screws (it says 8 to 12 mm in length. I used 10 mm). I tightened one side and it fit great, nice and snug. However on the other side, i heard a loud crack! I quickly stopped tightening tried t...

lcd tv mount

off-topic

tyblu

Yep

Nick T

7:02 PM

Apparently our mod disagrees :\

tyblu

nah, he's just into the 'christmas spirit'. ;)

the "Tesla Generator" works if you radiate it with microwaves.

... doing some simulations :D

'suppose a piece of steak would "work" if you radiated it, though.

Nick T

I forgot what frequency Tesla wanted to use; I think it was like 400 kHz?

tyblu

Dunno... but he's turning in his grave due to his name being stuck on this circuit.

Nick T

"Tesla found the frequency range up to 30 – 35 kHz 'to be most economical.'"

Wardenclyffe Tower

Wardenclyffe Tower (1901–1917) also known as the Tesla Tower, was an early wireless telecommunications tower designed by Nikola Tesla and intended for commercial wireless telephony, broadcasting, and to demonstrate the transmission of power without interconnecting wires. The core facility was not completed due to financial problems and was never fully operational. The tower was named after James S. Warden, a western lawyer and banker who had purchased land for the endeavor in Shoreham, Long Island, about sixty miles from Manhattan. Here he built a resort community known as Wardenclyffe...

tyblu

bugger.. microwaves don't make this thing work: was computational roundoff and cutoff errors.

Nick T

7:25 PM

where are you grounding the circuit?

tyblu

nowhere -- just using it as a reference for the input voltage.

Nick T

using what point of it

tyblu

Simulating the antenna as a voltage source, node 0 (GND) to 1 (DC block caps).

Bogus Tesla Generator
Vin	1 0	SFFM(1 1 100Meg 12 10k)
C1	1 3	0.2u
C2	1 2	0.2u
C3	4 6	100u
C4	5 4	100u
D1	3 4	Dgermanium
D2	4 2	Dgermanium
D3	6 3	Dgermanium
D4	2 5	Dgermanium
RL	5 6	10k
.model Dgermanium D IS=200p RS=84m N=2.19 TT=144n CJO=4.82p M=0.333 VJ=0.75 EG=0.67 BV=60 IBV=15u
.control
delete all
tran 1m 600
plot V(5,6)
.endc
.END

Nick T

Your entire thing is floating

tyblu

yep.

Nick T

7:30 PM

you should at least add some parasitic cap to ground

or just ground node 4

tyblu

7:41 PM

still ~50pV output from 1Vpp input, so 0.

Arlen Beiler

8:39 PM

Did you see the link in the comment? It links to the full document. I'd decided to see what would come up if I googled a phrase in the pdf, and found that. Figured I would be safe from copyright infringement if there is any.

Nick T

8:50 PM

@ArlenBeiler That patent you linked seems to have nothing to do with your question

It looks like an application of the photoelectric effect

Arlen Beiler

Here is a link to the document. The video is junk compared to it.

scribd.com/doc/41445605/TeslaSecret

Nick T

No, the two links you just added to the question

are totally unrelated

Arlen Beiler

removed them

Nick T

Hmm, @ArlenBeiler The entire document aside from the TOC looks blank to me, but the title is the same "Radiant energy generation"

Your circuit looks like it's trying to capture RF or other AC from parasitic capacitance

Arlen Beiler

I've doubted all along that the circuit I gave would work. It just didn't look right.

You'll be hearing from me soon with another question related to this.

tyblu

9:03 PM

wonder if I can use an nmos as a pull up if i'm pulling only a small amount of current...

Nick T

Your output voltage will always be Vth less than the positive rail then

tyblu

yep, just trying to protect an input and see if I can use nmos everywhere instead of pmos

--- V+
|
|--||
   ||--- ctrl
|<-||
|
R1
|------ input
R2
|
--- GND

Nick T

How are you protecting it

tyblu

V+ is a rough voltage source -- a semi truck source at the end of a few dozen meters of wire -- varying between 12V and 20V with spikes. The input is a 5V ADC. Am putting the FET there to 'turn off' the leg so it doesn't drain (gate will have pull-down resistor, too). It needs to be a pull-up control or the 'input' will go to V+ when current is zero.

Nick T

@ArlenBeiler I rolled back your question as it seems like those deal with the actual document. Added to my answer as well

tyblu

9:15 PM

input also has clamping diodes, resistor, and cap.

Nick T

2

A: Can you harvest electrical energy from the air?

To address the original question of "Is Nikola Tesla's free energy discovery...", Tesla never created a "free energy device". One of his noted ideas, however, was a system to intentionally transmit power wirelessly. Power companies don't intentionally radiate energy (as it's a pure loss for the...

@tyblu I don't get it...why can't you just use a voltage divider

and clamp diodes

tyblu

just so it isn't always pulling current.

Nick T

Ok...but if you care at all about the ADC accuracy, why would you inject some unknown quantity (Vth) into it

tyblu

I don't care all that much.. just within 0.5V or so. I think I can calibrate to that accuracy.

Nick T

Some guy I worked with would just use 2x 100kΩ resistors to monitor IGN on heavy trucks, direct connection to the micro

tyblu

9:19 PM

hope he used a dip socket for the micro, so he could replace it :P

Nick T

9-16 V normal, 100 V transients

Why

because you're going to drive enough current through a 100 kΩ resistor into a micro to kill it somehow?

tyblu

he never fried it with 100V transients?

Nick T

How much current is going to be going into it

1 mA

oh no.

That will totally blow up the input protection diode on the MCU...

tyblu

1mA

Nick T

Most micros are specified with a certain level of current injection

Arlen Beiler

9:22 PM

@NickT It works fine for me, you have to scroll down, of course.

tyblu

I still think i'll put the RC protection in there. I expect this to be abused...

Nick T

How much do you actually need to lower the power consumption of your device anyways? Is your input line the battery or some signal that will only be high when the ignition is on?

tyblu

it'll be one of a few things: single auto battery they're testing, truck +ve line (alternator + batteries), only the alternator, or a small 12V battery to power it for some other functions (tests trailer lights, etc.).

Nick T

Is this production at all or just test?

tyblu

just test.. I'll make one or two.

Nick T

9:27 PM

So why do you care about power consumption, saving a few pennies on a N-ch vs P-ch, etc?

tyblu

hmm.. too much free time?

Nick T

:P

tyblu

i mean.. I just ran SPICE simulations on a circuit I knew wouldn't give any output, for 2 hours.

Nick T

Signing up for a fake scrib'd account...scribdsucks: taken, scribdsucksballs: taken

scribdsucksmyballs: yay

tyblu

oh, got that bogus pdf.

Arlen Beiler

9:30 PM

I didn't need an account to look at it.

Nick T

All the pages are white for me

Arlen Beiler

what browser/OS

Nick T

FF4b8

tyblu

this link should be active in a few minutes: [removed]

Nick T

Eh, I downloaded it after being a jerkwad

lol, this paper just feels written by someone with no physics/eEE knowledge

> The ionosphere is where the irradiated energy of the sun stays. This area has a positive charge. The earth, at the bottom, has a negative charge. The air between the two other layers acts as an insulator, or buffer, keeping the "circuit" closed.

W5VO

9:38 PM

@ArlenBeiler, the schematic can't be found anywhere in the actual paper. It's only found in the wonderful video slide show.

Kortuk

-1

Q: Internal threading fix for Sony Bravia

I recently got a Sony BRAVIA 46". When I was mounting to an existing mount, I used the requested machine screws (it says 8 to 12 mm in length. I used 10 mm). I tightened one side and it fit great, nice and snug. However on the other side, i heard a loud crack! I quickly stopped tightening tried t...

lcd tv mount

W5VO

There's no indication how to "scale" this "generator" because it doesn't work in the first place.

Kortuk

@NickT, @tyblu, your mods do not disagree this is offtopic, I have no idea why there was an answer.

Arlen Beiler

Did you try it as described in the PDF?

Kortuk

@W5VO, You do not know until you buy the book!

You guys discussing the free power generation?

Arlen Beiler

9:41 PM

yeah

tyblu

hello @Kortuk. Free from the family clutches?

Nick T

@Arlen Did you read my updated answer at all? The generator you're talking about now uses the PE effect

Kortuk

@tyblu, I have alot of family in town till Wednesday. I only visit them once a year.

Nick T

And tesla coils are just antennas

W5VO

@Kortuk Arlen has kindly found a link that has the fabled "book"

Kortuk

9:41 PM

@tyblu, just trying to check in once in a while.

-1

Q: Internal threading fix for Sony Bravia

I recently got a Sony BRAVIA 46". When I was mounting to an existing mount, I used the requested machine screws (it says 8 to 12 mm in length. I used 10 mm). I tightened one side and it fit great, nice and snug. However on the other side, i heard a loud crack! I quickly stopped tightening tried t...

lcd tv mount

Is a good reason to check in regularly. I cannot believe it was still open, nor that there was an answer.

@W5VO, It is magic! Tesla was the king of free energy! Power should be free and it is a conspiracy!

Nick T

...by a mod

Kortuk

@NickT, Yes, He even stated it was off topic, I guess we all need our rep. It is closed now.

Arlen Beiler

Have any of you built a tesla coil?

Kortuk

This has happened before.

W5VO

@ArlenBeiler Yes. I remember it needing power to work

Kortuk

9:43 PM

@ArlenBeiler, I am very happy to see new people in here, forgive me for speaking off topic. I have to get back to family.

tyblu

@Kortuk even better reason: go up vote my questions. :D

Kortuk

@ArlenBeiler, you guys have fun.

Arlen Beiler

ok, you too

Kortuk

@tyblu, I upvoted that this morning.

tyblu

see ya.

Kortuk

9:44 PM

don't get too mad, I know how engineers get about technical discussions, you also did not need to remove your comment.

Have fun.

W5VO

@tyblu You're going to make me work for it, aren't you?

Nick T

There's a place down in K'zoo, MI that built twin TCs, pretty cool. They didn't use them to Tx/Rx, just make tons of sparks

tyblu

@W5VO your answer is the best one there.

@W5VO the wolves are circling, though... :D

Nick T

@tyblu Why are you dumping 500 rep on that, out of curiosity?

tyblu

@NickT eh.. seems to come fairly easily. I imagine 500 rep will be a drop in the bucket in the future, though it seems like a lot now.

W5VO

9:46 PM

The reason why noone would fund tesla coils for power distribution is because there's no way to charge based on use. It would be like trying to charge everyone that listened to a public radio station $0.50/hour

The PDF makes no mention of the circuit you drew. The only place I saw that circuit was in that presentation.

Arlen Beiler

Correct, it isn't in there. And I don't know where they got the one on the video.

tyblu

@W5VO I wonder if there's a way of detecting large, weak fields, Star Trek-style, too see the extra 'curl' near field 'users'.

Nick T

I wonder what would happen if you blew a ton of styrofoam (but without anti-static) beads up into some HV lines

Arlen Beiler

The one in the PDF is different. And it makes more sense too. I don't see how the presentation one is supposed to even work (it isn't grounded).

W5VO

If I remember the picture with the cell phone, there's a few things that scream "fraud". First, you can't account for all the wires in the picture. Second, you couldn't even identify all the additional circuitry required for charging the phone. Third, I'm not even sure that the cell phone was indicating that it was being charged!

Arlen Beiler

9:51 PM

Someone should build and mount the antenna with the spark gap and all and see if they even get a spark. I am curious as to whether it would work.

W5VO

@ArlenBeiler It doesn't have to work. All it has to do is look simple enough for you to want to buy the PDF.

Also suspect: in the video, he mentions that "5.2 MegaWatt Hours" come from the sun to the earth as ionized particles. If you forgive the wrong units, that's 5.2MW for the whole earth, which is almost nothing!

Nick T

Average solar irradiance is about 1 kW/m^2

@W5VO 5.2 MW·h per what...hour?

W5VO

That is about 26mW per square mile! wolframalpha.com/input/?i=5.2e6+/+(surface+area+of+earth)

Nick T

milliwatts?

W5VO

Mega Watts

Nick T

9:58 PM

oh, the charged particles

What?

tyblu

lol .. do electrons even stream from the sun? Thermionic emission, etc.. Obviously photons do en-mass, but what about other particles?

Nick T

Yeah dude, the sun is spraying tons of stuff out

W5VO

They used Mega-Watt-Hours instead of Mega-Watts

Arlen Beiler

Check pages 28-32

W5VO

but when it reaches earth, if you assume that it's 5.2MW, distributed over the surface it becomes 26 milliwatts per square mile

Nick T

10:02 PM

@ArlenBeiler Dude, the guy that wrote this paper has no scientific knowledge. He's attempting to describe the patent you linked in which Tesla is talking about transferring energy using UV/X-rays and electron beams

tyblu

@W5VO that calculation is a bit tricky, though, as its basically a parallel ray density intersection a hemisphere...

W5VO

@tyblu yeah, I was assuming that the ionosphere made things "work out". But even if you fiddled with orders of magnitude, it still is ridiculous. If you're on the equator, and get 10x that value, it's still 260mW per square mile.

Nick T

The whole premise is bullshit, how are you going to capture particles "in the ionosphere" with an antenna.

I dunno, I haven't seen this mythical video

probably do not want

tyblu

@NickT a big f*ing antenna, obviously. Maybe the Spaceballs gargantuan vacuum.

W5VO

@NickT The antenna can be as short as 30'

Nick T

10:07 PM

Did you read how insulators "close" circuits?

W5VO

I'm done reading. I haven't found a thing in there that makes me believe that the author knows what he's talking about, or that there is any possibility of his contraptions resulting in even a milliwatt of power received.

Nick T

Oh, I finally got why the circuit doesn't work...I thought it was a basic rectifier, but that plus DC blocking caps fails

Unless you have a full-bridge rectifier

W5VO

He uses mostly true statements to hide complete fallicies, so that the whole thing "sounds" reasonable to someone not familiar with science.

@nickt How about this for it failing: there is no current loop

tyblu

the 2 caps on the left are DC blocks; everything to the right looks like a multiplier to me (x4), but the input isn't wired correctly

Nick T

For what, the antenna input to ground? I assumed you might ground the negative terminal

tyblu

10:15 PM

:P

Nick T

on the next page:

> However, just like in his experiments, you can put a Tesla coil into the equation.

He's right about that, instant awesome: just add tesla coils

All the pictures in this PDF are direct rips from WP

If you had an ideal capacitor (say parallel plate) charged up, but couldn't touch it, could you discharge it?

tyblu

10:31 PM

am I allowed to irradiate the electrolyte, or does that constitute touching?

Some THz waves or just plain high voltage/field in the void will ionize the gap, creating a current path.

Could use a rod to discharge it, but don't actually touch the contacts -- just go close enough such that the air ionizes and you get a spark gap.

Arlen Beiler

10:44 PM

Well, I picked up the hammer, and we will see whether it is a nail in or a nail out of their coffin. I am asking for my money back. They have a 60 day money back guarentee.

At any rate, the coffin already has so many nails that it won't help them much whether they do or don't.

Transcript for

Electrical Engineering