Tesla has applied for a patent for a new electromagnetic windshield-wiper system • Hacker News Board

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#121

Post by taneq » Sun, Sep 15, 2019, 2:01 PM UTC

brianpgordon wrote: post #39

If they want to have one single blade move back and forth, that's cool, but this seems like a bafflingly complex way to do it. What's wrong with a normal linear actuator? It's powered by a regular electric motor (something right in Tesla's wheelhouse), can be built very reliable, and is plenty efficient. There's no reason to build the Space Shuttle when people just want an electric car, and won't be able to tell the…

Yeah, I would have thought a traditional electric motor turning a pulley which drives a belt would be a far easier and more efficient way to do it.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#122

Post by whenchamenia » Sun, Sep 15, 2019, 2:06 PM UTC

jondumbau wrote: post #117

wffurr wrote: post #115

Earlier quoted context omitted.

Additional power draw on the accessory circuit places increased load on the alternator which in turn causes the engine to run a little harder than it otherwise would. Thus burning a little extra fuel.

Cheers, alternators are essentially magic to me. Id have presumed they were generating 'enough' power at all times the engine was running.

They produce based on current draw, but have a maximum output, usually around 60-85a for and older car, to 120-240a at 14.4vdc for a newer car or truck. There is no permanant magnet, so the coils require power to generate power. Its quite interesting.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#123

Post by adamkittelson » Sun, Sep 15, 2019, 2:19 PM UTC

paganel wrote: post #41

Why replace a simple but essential thing that works (i.e. current wipers) with a more complicated one that it will have lots of additional ways to fail?

Speaking of... on the model 3 rather than using standard rain sensors for the automatic wipers they got cute and used the autopilot camera and it’s fucking awful. I constantly have to screw with the wiper settings when it’s raining (which are on the touch screen because of course they are) because the auto setting is so bad. I love the car overall but this design decision was a mistake.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#124

Post by fyfy18 » Sun, Sep 15, 2019, 3:21 PM UTC

Have there been any developments on glass technology than can repel water? I use a anti-rain coating (a la Rain-X) which works pretty well, but you need to be above 80km/h for it to work effectively.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#125

Post by traverseda » Sun, Sep 15, 2019, 3:33 PM UTC

I was expecting an electrowetting/microfluidics solution.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#126

Post by fyfy18 » Sun, Sep 15, 2019, 3:34 PM UTC

whenchamenia wrote: post #122

jondumbau wrote: post #117

Earlier quoted context omitted.

Cheers, alternators are essentially magic to me. Id have presumed they were generating 'enough' power at all times the engine was running.

They produce based on current draw, but have a maximum output, usually around 60-85a for and older car, to 120-240a at 14.4vdc for a newer car or truck. There is no permanant magnet, so the coils require power to generate power. Its quite interesting.

Further to this the 12V battery effectively acts as a big capacitor while the car is running, to smooth out the power that is available.

I found this out the hard way a couple of years ago. My 12V was dead, yet I managed to jump start the car and get it running. I thought it would be ok to drive to get a new battery, as long as I kept the engine running high enough. After a couple of km the dashboard lights started to dim, so I tried reving it as high as I could, but the battery wasn't able to buffer the power and supply the ignition system, so the engine stopped. It was rush hour and I was in the middle lane, so it wasn't a particularly fun wait for the tow truck.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#127

Post by JoeAltmaier » Sun, Sep 15, 2019, 4:01 PM UTC

Can't be lifted, when I want to squeegee the entire windshield at the service station. Can't be replaced without decoupling from complex mount. Probably less torque so mud/slush/snow will stall it.

A terrible idea, unless you're in California and drive in mostly fine weather.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#128

Post by close04 » Sun, Sep 15, 2019, 4:07 PM UTC

Udik wrote: post #118

simias wrote: post #111

Earlier quoted context omitted.

I think it's fairly obviously mainly a marketing move. These wipers (judging by the drawings) look cool and futuristic. If they ever implement them I'm sure that's going to be the main motivation. I can be very critical of Tesla but if there's one thing they achieved it's making electric vehicles that look cool. I don't think many teenagers saw a Prius as an aspirational vehicle but I'm pretty sure you could find Tes…

The only possible thing I see of practical value in this solution is that it might (might, not sure I understood well) reduce the amount of moving parts and gears. Essentially the entire motion would be controller electronically, no gears or motors.

Given the current reliability of classic wiper systems I don't think this is the improvement. Part of the reasons classic wipers have multiple moving parts (basically motor + rack and pinion) is that you want to guarantee they stay in sync and never overlap. You can put 2 simple motors on them for similar effect like the Tesla design. Tesla's solution focuses on design rather than better technical specs.

The claim that "the electromagnetic moving block induces minimal friction" says very little considering you achieve the exact same effect with a classic wiper arm mounted on a single electric motor. You probably want more than one arm anyway.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#129

Post by drusepth » Sun, Sep 15, 2019, 4:43 PM UTC

Scoundreller wrote: post #83

majewsky wrote: post #70

Earlier quoted context omitted.

That's a worse slogan though. Compare "Now with 10% more efficient windshield wipers!" and "Now with 10% dimmer screens!"

Usually when it’s raining there isn’t much need to run the display at full brightness. It’s largely a wash.

Why not dim the screen _and_ have more efficient wipers? ;)

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#130

Post by drusepth » Sun, Sep 15, 2019, 4:45 PM UTC

dannyw wrote: post #101

rumanator wrote: post #90

Earlier quoted context omitted.

> 50W for 5 hours is 250Wh, which is a mile extra range. That’s worth having. That represents about 0.5% of a Tesla's advertised range.

You do 10 of these things and you have 5% better range, more than your competitor who ignores 0.5% savings.

While I agree with you and am excited for whatever improvements can be made, I think the most likely retort to this argument is "While you're worrying about 10 0.5% savings, your competitor is focusing on optimizing things that actually matter."