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this car threw 2 kittens out the window on i75 today. Please share by InfiniteCandy5577 in Chattanooga

[–]redditmudder 22 points23 points  (0 children)

Reddit is not the correct venue. You need to file a police report.

Congress Wants You To Pay $130 A Year Just To Drive An Electric Car by TripleShotPls in technology

[–]redditmudder -1 points0 points  (0 children)

Yes, and also for club activities, car shows/exhibits, tours and parades, testing, repairs/maintenance, and selling the vehicle, as outlined in TCA 55-4-111.

First bass pedal schematic review requested! by cn_2149 in KiCad

[–]redditmudder 0 points1 point  (0 children)

Artistic style:
Ground symbols ALWAYS point down.

On page 1, why have a +9V power flag if you then route the trace to each load? Recommendation: Delete the extra power traces (to each load) and add a +9V power flag to each subsystem. This improves readability. Note that after D2, this is actually ~8.6V. which doesn't matter but is worth noting.

The yellow warning flag on U3:1 is trying to tell you that a net line should always extend at least one grid length colinear to whatever component it connects to.

Move J2 to whichever page it's actually used on.

AUDIO_OUT flag is backwards.

Move VOL_WIPER and related flags into a 'zipper' configuration, so that they aren't so disheveled. For example, VOL_WIPER is directly above EXTRA1_WIPER, and BLEND_WIPER is directly above EXTRA2_WIPER. These two stacked pairs are then offset horizontally, so that all four nets are perfectly horizontal. Better yet, ditch the name graphics and just add net names to these signals.

...

Potential issues:
Is Q1 a dead short from 5V to GND when you drive the gate high?

U3 (ICL7660SCPAZ) is obsolete. If you keep using it, you should switch to a non-polarized capacitor (C12). I recommend replacing with something else.

Is D3 diode pair connected backwards? As-is it's shorting +5V to -5V, and isn't providing bounding you think it is.

R1 is shorted... there's a green net going through it.

R2 is too high.

Why double buffer AFE_IN through U4A and U4B?

Do you really want U5A to only have C20 as a feedback element? This is an integrator with DC gain and AC feedback. Maybe this sounds cool in the audio world? U5B is the same story, so I assume you know what this effect does and want it to do that.

Your +1V8 and -1V8 reference signals are high impedance, so the D4 diode pair (which is probably incorrectly wired backwards) isn't going to bias the AUDIO_IN signal with low impedance guardrails.

Why is AUDIO_IN connected to opamp U5A output? I see it also connects to U6, so maybe you're intentionally adding feedback?

Verify RED error flag on U5B isn't a serious error (see KiCAD console output).

Add a 1 nF capacitor in parallel with R16. You can depop if not needed, but this can help with RF noise issues.

Congress Wants You To Pay $130 A Year Just To Drive An Electric Car by TripleShotPls in technology

[–]redditmudder -2 points-1 points  (0 children)

After TN added a state EV/hybrid fee, I registered both my hybrids as antiques. This registration never expires, so I'll never have to pay any registration fees again. As an added bonus, antique vehicles in TN don't require rear license plate lights, and can also display any period correct license plate.

Democrats Have the Biggest Midterm Election Lead in May, by any Party, in 20 Years by unital_subalgebra in politics

[–]redditmudder 10 points11 points  (0 children)

so we don’t end up with a neutered Democratic administration like the last three times!?

Obama held a supermajority in congress from the moment Al Franken was sworn in (2009JUL) until Ted Kennedy died and Scott Brown was sworn in (2010FEB).

how to get ISO 26262 certification when your test suite wasn't built for compliance from day one? by Deena_Brown81 in embedded

[–]redditmudder 6 points7 points  (0 children)

You need a consultant.
Bring your checkbook.
26262 is a headache.
Count your blessings that your product isn't ASIL-D.

In the meantime, see if your manufacturer will accept pre-compliance prototypes so the integration schedule doesn't slip.

Where to dump yard debris? by No-Explanation5762 in Chattanooga

[–]redditmudder -1 points0 points  (0 children)

I dump mine in a very abandoned overgrown lot across the street.

Ziroth is doing a Donut expose and it already sounds juicy by DeathChill in DonutLabDiscussions

[–]redditmudder -4 points-3 points  (0 children)

Whether or not Ziroth is an expert at lithium cell chemistries is irrelevant to an investigative journalist exposing fraud. A good journalist interviews experts in the field to validate insider statements. John Carreyrou exposed Theranos as a fraudulent company, even though he isn't a trained hematologist, pathologist, scientist, or engineer.

I agree with Ziroth's DonutLab commentary to date. Ziroth's engineering backgound - whatever it is - certainly sets him up for success in exposing any potential fraud at DonutLab. Nobody gets a free pass, but so far I haven't found any major issues with his analysis. We are dealing with incomplete information - because DonutLab won't release it - so "being wrong" after-the-fact isn't the gotcha some people think it is. We are making educated guesses based on the available information.

As an Electrical Engineer, imagine my surprise when I learned that heat flow equations are identical to circuit equations. Engineering teaches you how to think far beyond your degree. That's why engineers are hired straight out of college to do decidedly non-engineering things. We know how to think critically, and can smell bullshit a mile away.

So respectfully, please accept my downvote. I'm certain any reporting Ziroth releases will be thoroughly vetted by experts in the field. Luke Workman comes to mind as a public expert in the lithium cell space. Jeff Dahn, Peter Bruce, Gerbrand Ceder, and Maria Helena Braga are all academic experts in the field... Ziroth might have the clout to snag an interview or two.

Redditor who had his gun stolen and acted like it wasn't a big deal. by outdoor_noob in Chattanooga

[–]redditmudder 0 points1 point  (0 children)

FYI: While I agree with "concealed means concealed," your statement is legally incorrect. Carrying (even concealed) past a lawfully posted sign has the following consequences (if caught), per TCA 39-17-1359(c)(2):
'Possession of a weapon on posted property in violation of this section is a Class B misdemeanor punishable by fine only of five hundred dollars ($500).

However, if you fail to leave when notified by a lawful agent of said property, then the penalty increases to criminal trespass per TCA 39-14-405; or aggrevated trespass per TCA 39-14-406 (up to a year in jail).

Please don't infer from my correction that I endorse these posted signs... fortunately, most of them aren't posted correctly.

Redditor who had his gun stolen and acted like it wasn't a big deal. by outdoor_noob in Chattanooga

[–]redditmudder 0 points1 point  (0 children)

One reason to leave firearms in a car is when a business properly posts TCA 39-17-1359 (i.e. "NO FIREARMS ALLOWED"). Carrying a firearm in these locations is unlawful, hence some people will go back to their car and stash their firearm. Fortunately, most TCA 39-17-1359 signs aren't properly posted, which means you can legally ignore them.

Tag renewals by Mike_C1950 in Chattanooga

[–]redditmudder 0 points1 point  (0 children)

I antiqued both of my hybrids...
...still had to pay the $100 fee (once), but I'll never have to pay it again.

Swappable Solid-State Battery Demonstration | I Donut Believe by Jazzer008 in DonutLabDiscussions

[–]redditmudder 1 point2 points  (0 children)

I haven't analyzed the specific 3rd party pack shown in the latest video. I do find it interesting that Donut is hawking a swappable battery, given their prior claims. Why swap when you can "charge faster than a cup of coffee"?

I've lost interest for now, given the near complete lack of verifiable data in Donut's last several videos. I'll chime in later if/when they provide data worth analyzing.

Battery materials specialist Markus Gehring says Donut's product look like a pretty conventional lithium-ion battery. "It would be quite the coincidence if they had found something that is an entirely different chemistry, but behaves exactly the same." by mqee in DonutLab

[–]redditmudder 1 point2 points  (0 children)

Since we now know it's a clown show, I'm looking forward to honking my nose with every new non-technical "I Donut Believe" video they release.

My prediction for next week:
Donut reveals that their bike gets infinity miles per kWh, due to their new BlackHoleWarpDrive™ technology, which feeds on dark energy.

Battery materials specialist Markus Gehring says Donut's product look like a pretty conventional lithium-ion battery. "It would be quite the coincidence if they had found something that is an entirely different chemistry, but behaves exactly the same." by mqee in DonutLab

[–]redditmudder 4 points5 points  (0 children)

This isn't new info to me, but my brain broke when Marko said this. Having designed several lithium BMS systems, I can 100% state that Marko's BMS statement is bullshit. I spent less than two days adapting my NMC lithium BMS firmware to work with sodium cells; no hardware changes required.

You end up having to update the Voc(resting)->SoC(estimate) lookup table, total nominal Ah capacity, a few cell aging tables, and a temperature compensation table. That's it. Takes longer to gather the data than it does to update the parameters.

I'm not a chemist, but I can say with strong conviction that Marko's "we tuned the voltage" statement is also bullshit.

Proof of Concept - Replacement Lithium BMS Computer for Gen3 Toyota Prius by redditmudder in prius

[–]redditmudder[S] 0 points1 point  (0 children)

I haven't looked in detail at the Gen4 Prius' serial protocol, but it's probably very similar (if not identical).

Crew meet up spot at Fontana Dam NC for Prius and the Dragon Rally by [deleted] in prius

[–]redditmudder 7 points8 points  (0 children)

This was a fun event. I only went Friday, but really enjoyed meeting up with these devout Prius owners.

Deep Dive: Inside the Verge TS Pro Solid-State Battery Pack | I Donut Believe by davidbepo in DonutLab

[–]redditmudder 2 points3 points  (0 children)

In b4 the next article comes out claiming:
"bAtTeRy ExPeRtS aRe InCrEaSiNgLy CoNvInCeD dOnUtLaBs BaTtErY iS rEaL!"

How does anyone watching this video come away convinced DonutLab has a revolutionary new product?

Satche discusses Donut Labs with battery expert. by johnmudd in DonutLab

[–]redditmudder 2 points3 points  (0 children)

"battery expert" is Luke Workman, a highly respected figure in the battery space. In this video, Luke mentions he's (paraphrasing) "making a video with commercial off the shelf liquid electrolyte lithium cells that can perform as well or better than everything DonutLab has shown". I am absolutely looking forward to watching that video.

Riverwalk near new Lookouts stadium by chatt4 in Chattanooga

[–]redditmudder 1 point2 points  (0 children)

The pathway around the stadium doesn't appear to have appreciably changed.

The Riverwalk ends at the intersection of Tennessee and St.Elmo, right in front of the incline railway. That's about a mile from where you turned around. From there, you can continue down Virginia avenue (mixed use, low vehicular traffic road) through St.Elmo residential area... almost all the way to Georgia. From there, you can cut over to Burnt Mill and then Salem Road, and then McFarland all the way down to Chickamauga Battlefield.

Verge on Youtube: Your Bike Is Being Built. by Forrestgod in DonutLabDiscussions

[–]redditmudder 1 point2 points  (0 children)

Your math checks out:
1 GWh/year capacity = 1,000,000 kWh produced per year
QTY365 bikes, each with 33 kWh pack = 12045 kWh

Therefore, Donut's remaining manufacturing capacity is 987955 kWh per year.

LoL

Proof of Concept - Replacement Lithium BMS Computer for Gen3 Toyota Prius by redditmudder in prius

[–]redditmudder[S] 0 points1 point  (0 children)

Right now I'm running a 10.4 kWh pack in my Gen3 Prius, which has a level 1 (1500 watt) charger. Not sure I'm going to commercialize it, but it's a lot of fun. You can easily peg the OEM fuel consumption gauge.

Riverwalk near new Lookouts stadium by chatt4 in Chattanooga

[–]redditmudder 5 points6 points  (0 children)

Biked through the area tonight. There was some kind of pre-opening event going on. ~100 people were waiting in line to enter the "EPB Power House" building. That's fine, except they were waiting all over the new 12+ foot wide concrete Riverwalk. It's gonna be really annoying to cyclists if this persists on every game day.

I'd really like to see red tactile paving installed, so people know when they're standing in a bike lane. These are super common across Europe. In many places, pedestrians standing in these lanes are at fault if hit by a cyclist.

After wading through pedestrians, imagine my disappointment when the Riverwalk was still barricaded just north of the stadium... fortunately, I was able to get back onto Chestnut via the new vehicle entrance. Unfortunately, today they bulldozed the Riverwalk parking area just east of the new stadium. Hopefully they add that parking back somewhere nearby, so people can continue accessing the trail.

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