EEVblog #104 - Live Show #3  - Page 1
Forum section: electronics / general

author: DJPhil
author_rank: Frequent Contributor
timestamp: August 13, 2010, 12:20:47 am
content: There is still a Delorean Motor Company -http://www.delorean.com/They sell new builds and used originals along with all sorts of parts, etc.Not cheap by any means, but not as expensive as I thought.Tried to post as a comment in Youtube but it was being difficult.

author: EEVblog
author_rank: Unknown
timestamp: August 13, 2010, 12:26:56 am
content: Quote from: DJPhil on August 13, 2010, 12:20:47 amYoutube's comment system is retarded, and keeps being patched daily by the latest outsourced work experience student.Dave.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 13, 2010, 03:32:35 am
content: As for the live (nonisolated) circuits, they're all over the place nowadays. The heavy transformers have all but disappeared (with just a few exceptions) in favor of high frequency transformers, meaning that the high frequency inverter circuits are live. The high frequency means that they can cause serious burns even if an isolation transformer is used.I remember the time when I first got into high voltage electronics. My first high voltage circuit consisted of the core from a PC power supply output filter wound with wire from a floppy drive motor to step up 3 AAs or something to a few hundred volts. I used it to light up fluorescent bulbs, zap bugs, and even to "light a neon bulb with one wire" to confuse my science teacher. Then a friend of mine gave me a flyback transformer out of a broken monitor and I built a simple inverter using a transistor out of a PC power supply, using 8 AAs to power it. It's a lot of fun. And I still have a fascination with high voltage, probably because I never really got shocked.Combine that with my new interest in environmentalism and the result is that my best friend Allie Moore says that I'll be the next Tesla...http://www.diyaudio.com/forums/lounge/7181-more-engineering-humor-57.html#post2269166Maybe I'll be the engineer as well as the "tree-hugging backyard mechanic" in that joke...

author: Time
author_rank: Frequent Contributor
timestamp: August 13, 2010, 01:03:02 pm
content: Quote from: NiHaoMike on August 13, 2010, 03:32:35 amThe inventor of the Tiffany Yep, is he from USC and just got his PhD? If so, I met him at a conference this year.High voltage electronics are my specialty. I've designed something that uses as little as 300 V (yes 300 V really isnt much) all the way up to 42 kV. Some of my colleagues work with marx generators which can produce 500kV discharges. When you turn your device on and you start hearing the crackle and sizzle of the corona across the exposed metal surfaces you know you are dealing with real HV.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 13, 2010, 01:45:57 pm
content: Quote from: Time on August 13, 2010, 01:03:02 pmUnfortunately, the "Tiffany Yep" ignition system has not yet been invented to my knowledge. But maybe I'll be the inventor. I envision a two stage design where the 12V is stepped up to 600V or so with a DC/DC converter, which runs some IGBT ZVS/ZCS half bridges driving resonant transformers to fire the spark plugs. But as the GM part of the joke indicates, you can have a great ignition system and still get a car that gets poor mileage if the rest of the system is not designed right. So the engine I plan to use will be a direct-injection lean burn Atkinson cycle 4 cylinder. There also will be large LiFePO4 batteries, "Amy Aldrich" water injection (piezoelectrics to mist water into the intake), and of course, aerodynamic modifications.314 MPG in a Prius by only adding LiFePO4 batteries:http://priuschat.com/forums/gen-ii-prius-fuel-economy/82387-new-tank-record-3536-miles-314mpg-in-prius-ii-plug-in-hybrid-electric-vehicle.html100 MPG in an old Civic with aerodynamic modifications and an old lean burn engine:http://aerocivic.com/I think 500 MPG is possible with today's technology.

author: Time
author_rank: Frequent Contributor
timestamp: August 13, 2010, 02:35:41 pm
content: Oh, this is what I thought you were talking about:http://pulsedpower.usc.edu/combustion.html

author: TopherTheME
author_rank: Regular Contributor
timestamp: August 15, 2010, 02:19:36 pm
content: Quote from: NiHaoMike on August 13, 2010, 01:45:57 pmYou do know if you actually built an engine like this you would have less of a negative environmental impact by setting your car on fire rather than driving it, right?QuoteFor a conventional car like a 4 door sedan, this is not practically possible.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 16, 2010, 01:13:15 pm
content: Quote from: TopherTheME on August 15, 2010, 02:19:36 pmYou could say that about almost any car. The most environmentally friendly vehicle is a bicycle, but it generally cannot be a universal substitute for a car.QuoteThe "InfraRed" Prius gets 314 MPG and it's a 5 door hatchback, the only difference between that and a normal Prius is the large battery pack. Add a few more technologies and 500 MPG (in the city, at least) should be well within reach.

author: TopherTheME
author_rank: Regular Contributor
timestamp: August 16, 2010, 06:32:51 pm
content: Quote from: NiHaoMike on August 16, 2010, 01:13:15 pmNo you can't. All cars sold in the US and Europe are designed to meet very high emission regulations, i.e. they're not NOx and HC factories like the car you previously described.QuoteThe "InfraRed" Prius is a plug in hybrid. That 315mpg does account for the energy used to charge the batteries.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 16, 2010, 07:09:18 pm
content: Quote from: TopherTheME on August 16, 2010, 06:32:51 pmIf you're trying to get 500 MPG, you can't afford to lose valuable energy to incomplete combustion. Lean burn will greatly reduce HC and CO emissions (until it goes so lean that it doesn't ignite, which is obviously undesirable in every way). Water injection takes care of the NOx.http://en.wikipedia.org/wiki/Water_injection_%28engines%29QuoteAnd as for CO2, just getting to 500 MPG takes it really low.QuoteIt is a legitimate technology and a good direction for cars to go. It pollutes less and reduces foreign oil dependency.

author: TopherTheME
author_rank: Regular Contributor
timestamp: August 17, 2010, 01:47:10 pm
content: Quote from: NiHaoMike on August 16, 2010, 07:09:18 pmThere is very little incomplete combustion in the modern PI engine at near stoichometric conditions, much better than you would find in any DISI engine. A lean burn, phi < 0.7, does not greatly reduce HC emissions, it increases them. And water injection does not "take care of" NOx. In DISI engine it often doesn't do a whole lot in terms of NOx emissions, unless you're operating at relatively high combustion temps, i.e. Zeldovich mechanism is dominant. Water injection often leads to greater inefficiencies as well.QuoteHow so?QuoteThat 500mpg is not an actual metric of the engine efficiency, its a measure of how far the vehicle can travel with an engine AND rechargeable batteries. The energy required to charge those batteries had to come from somewhere. Perhaps a coal fired power plant.QuoteI'm not arguing that the development of hybrid technology, whether by an OEM or in someone's garage, should not be pursued. I'm just stating that some of the methods you are proposing and that other people have developed actually do more harm to the environment than good as well as the way people measure the performance of these methods are incorrect and/or misleading.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 17, 2010, 03:55:05 pm
content: Quote from: TopherTheME on August 17, 2010, 01:47:10 pmWhat if the car came with a bunch of solar panels you install on your house? (Let's assume the initial carbon footprint is negligible, although a proper analysis could be done later.) Or what if the car had an onboard radio energy receiver that uses nearby radio stations to recharge the batteries? (Assume the very difficult engineering hurdles were somehow overcome.)QuoteThere will never be a car that will net "good" for the environment, it's just about minimizing the carbon footprint. As far as the environment is concerned, the best car is no car. In the ideal world, I would be riding a hybrid bicycle (infinite MPG), but it just isn't practical in many places yet.

author: gildasd
author_rank: Frequent Contributor
timestamp: February 01, 2015, 08:53:40 pm
content: Sorry to dig up an old topic, but Delorean.