EV-specific trailers incoming!

[SwampNut]

They engage the friction brakes, we know that for sure, it's documented. They're not going to waste a bunch of power holding a motor; just not the Tesla way.

Electric motors produce very little power at very low speeds, and therefore, present very little restriction to movement. Sorry, I used a poor term, I'm trying to balance a lifetime of electrical experience with not talking to others above their heads. The resistance to motors turning, without USING power to create artificial resistance, is super low at low speeds. Native regen braking is effectively zero when stopped.

Again, this has been super easy to measure and play with on my hub-drive e-bike. Some things were obvious, some were curious. Like the inverter has a different signal for "slow me down" versus "lock me up." And let me tell you, when you get them backwards, get to 20 MPH, and hit the brake...good times...

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[Crissa]

Does the car apply the friction brakes when stopped in One pedal driving mode? I just assumed they held the motors at zero speed.

Yes. Not alot, but enough to not roll back on a hill. It's a safety feature. If creep is selected, it has a different balance point.

-Crissa

 

[SwampNut]

Yes. Not alot, but enough to not roll back on a hill. It's a safety feature. If creep is selected, it has a different balance point.

-Crissa

I've never tried creep on the Tesla, but have driven a Bolt with it on. I guess I should try it. What a balancing act to make a car do something it doesn't natively want to do. I very much hate all of the fake human interfaces and skeuomorphic that are used to make something modern seem familiar. We'd be so much farther along if people weren't coddled in old-think.

Someone asked me to fax something this morning. I want to know why I can't issue a shock correction over the phone to them.

 

[Bill906]

They engage the friction brakes, we know that for sure, it's documented. They're not going to waste a bunch of power holding a motor; just not the Tesla way.

Electric motors produce very little power at very low speeds, and therefore, present very little restriction to movement. Sorry, I used a poor term, I'm trying to balance a lifetime of electrical experience with not talking to others above their heads. The resistance to motors turning, without USING power to create artificial resistance, is super low at low speeds. Native regen braking is effectively zero when stopped.

Again, this has been super easy to measure and play with on my hub-drive e-bike. Some things were obvious, some were curious. Like the inverter has a different signal for "slow me down" versus "lock me up." And let me tell you, when you get them backwards, get to 20 MPH, and hit the brake...good times...

Good to know they do engage the brakes. I assumed so, but didn't know it was documented. Thanks for that.

An electric motor on an inverter like the ones I'm sure Tesla uses, can produce any torque at any speed within the limits of the particular motor size. Electric motors are used on cranes. On a decent crane system, the electric motor is started and is producing torque to hold the load before the mechanical brake is engaged. Then the load is lifted or lowered. If it's commanded to stop, the motor/inverter maintains control of the load all the way to zero speed and held there by the motor until the mechanical brake is commanded to engage. AFTER the mechanical brake is engaged, the motor stops producing torque and shuts off.

Regen is a term for power. Power = speed x torque, so yes, at zero speed there is zero regen power.

I'm guessing the "lock me up" command engages a function often called "DC injection braking". Motor speed is a function of AC frequency. DC voltage can be thought of as at a frequency of zero hertz. Applying DC current to an AC motor is essentially commanding zero speed. Where the "slow me down' command simply commands a frequency lower than the speed the motor is turning. This is all speculation on my part. There are a number of different ways to perform the functions described.

 

[Crissa]

I've never tried creep on the Tesla, but have driven a Bolt with it on. I guess I should try it. What a balancing act to make a car do something it doesn't natively want to do. I very much hate all of the fake human interfaces and skeuomorphic that are used to make something modern seem familiar. We'd be so much farther along if people weren't coddled in old-think.

Someone asked me to fax something this morning. I want to know why I can't issue a shock correction over the phone to them.

A fax is a vaguely secure method of sending a copy of a document. It is much more difficult to be man-in-the-middled. And most people don't have access to one of the signature systems some states and banks use to digitally secure signatures and documents.

And how an electric motor operates needs to be changed into something a Human can operate. The power curve of an electric motor isn't conducive to keeping the tires attached to the road, let alone any basic variable resistors. And even the concept of holding the motors still or resisting rolling (like your e-bike) are a programatic response.

UI has to be developed somehow.

-Crissa

 

[Ogre]

A fax is a vaguely secure method of sending a copy of a document.

**ROFL**

I used to work in healthcare. While deliberate MiTM attacks were uncommon, faxes with incredibly personal data very very frequently ended up going to the wrong destination. We’d have non-medical people calling us who had dozens of faxes popping up onto their machines from us (wrong number inputted by clerk) or for us all the time.

I would never use the word “Secure” with faxes. Yes, they are somewhat immune to MiTM so long as you have physical line security, but accidental leakage is still a huge security problem and it was/ is incredibly common.

 

[SwampNut]

A fax is a vaguely secure method of sending a copy of a document. It is much more difficult to be man-in-the-middled.

This is my industry. I run a VoIP company and do voice systems engineering. I've worked in telecom since the 90s. That statement is a common myth, but a myth for sure. I've shown a fax MITM in the 90s using a radio shack tape recorder. It's trivial. Most email is secure in transit.

I should add "mythical beliefs" to my rant about skeuomorphs.

 

[Crissa]

I notice both of you failed reading comprehension.

I used 'vaguely' and 'more difficult'. It is more difficult than to intercept a email. It is not secure from a wiretap - but neither is your email.

And inputting the wrong address happens just as frequently. That's not a fault inherent to any specific method.

-Crissa

 

[Bill906]

**ROFL**

I used to work in healthcare. While deliberate MiTM attacks were uncommon, faxes with incredibly personal data very very frequently ended up going to the wrong destination. We’d have non-medical people calling us who had dozens of faxes popping up onto their machines from us (wrong number inputted by clerk) or for us all the time.

I would never use the word “Secure” with faxes. Yes, they are somewhat immune to MiTM so long as you have physical line security, but accidental leakage is still a huge security problem and it was/ is incredibly common.

I was on the other end of this very problem. The phone number of our work fax machine was the same as a healthcare providers fax number except two numbers were transposed. We'd get tons of wrong faxes for healthcare including a lot of personal information.

 

[SwampNut]

It is more difficult than to intercept a email.

It's not. Most email is encrypted in flight. Speaking of reading comprehension...

 

[Ogre]

I notice both of you failed reading comprehension.

You say this. Then make a post which re-iterates half of the post you are responding to.

 

[Crissa]

It's not. Most email is encrypted in flight. Speaking of reading comprehension...

That is not considered secure, by healthcare standards.

-Crissa

 

[Crissa]

You say this. Then make a post which re-iterates half of the post you are responding to.

Look, if you want to make irrelevant arguments, go ahead. Putting the wrong address on something no matter the system, is a security risk.

If you want to make straw-man attacks against what I said, go ahead.

They're still straw. I pointed out the words you skipped and you decided not to read them.

-Crissa

 

[SwampNut]

It’s incredible the lengths to which some people will argue a falsehood. Intercepting a fax takes little effort and a $10 recorder. Intercepting an email is exceedingly difficult if not impossible, with expensive equipment.

In addition to that, my original commentary on the topic made no mention of security. It was about how people go about unthinkingly doing things the old way, and how too much of our world is geared around letting humans be lazy and stupid. The fact that fax has absolutely zero security while most other methods are better was not even in my mind.

Next up, the stupid things that people do while trailering because they think they know everything.

 

[Crissa]

It’s incredible the lengths to which some people will argue a falsehood. Intercepting a fax takes little effort and a $10 recorder. Intercepting an email is exceedingly difficult if not impossible, with expensive equipment.

In addition to that, my original commentary on the topic made no mention of security. It was about how people go about unthinkingly doing things the old way, and how too much of our world is geared around letting humans be lazy and stupid. The fact that fax has absolutely zero security while most other methods are better was not even in my mind.

Next up, the stupid things that people do while trailering because they think they know everything.

A special recorder, physical access to the wires... something not needed to intercept email.

-Crissa

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