• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Help converting 220 AC to 220 DC @40 amps

Status
Not open for further replies.

electric_ride

New Member
Here's what I'm doing folks.I am tired of paying for gas so I built a electric vehicle .Now I want to extend it's range to go farther using a generator . I know I need to build a rectifier but do I need something to limit the current in case in should exceed the limits I am sending the vdc side to a battery pack then using the power .I am going to use a 10k watt generator to start then once I prove it can work I will step up to a 15 or 20k generator and drive it cross country proving it can be done better than Toyota and others have. Then maybe we can get the world to wake up to what can really be done. Can or will some of you that know this field well help me ?My current project is a 95 S10 and a 95 Eclipse is next in line .I currently drive a 144vdc 95 S10 .Thanks ER
 
Last edited:

Sceadwian

Banned
That math on that seems a bit flakey to me. 10kwatt's is the equivilant to a 12 horsepower engine, how is that going to power a car? 220AC to 220 DC is simple, use four diodes in a basic bridge configuration. 40amps is a drop in the bucket compared to what modern power diodes can handle.
 

electric_ride

New Member
Sounds good , your math is correct on the HP as well , but someone who claimed to be a engineer claims I need to limit my current because the batteries will try and draw more from the generator is this true?Also yes the 10k watt is just a little small that's why once I prove how well it will work I will step up to a 15 or 20k watt generator plus I already have the 10k.
 
Last edited:

Nigel Goodwin

Super Moderator
Most Helpful Member
Why not just connect the engine to the wheels?, FAR more efficient than using it to power an alternator and charge a battery (both of which make losses).
 

jpanhalt

Well-Known Member
Most Helpful Member
electric_ride said:
Here's what I'm doing folks.I am tired of paying for gas so I built a electric vehicle .
What fuel are you going to use to power your generator? John
 

mvs sarma

Well-Known Member
Nigel Goodwin said:
Why not just connect the engine to the wheels?, FAR more efficient than using it to power an alternator and charge a battery (both of which make losses).
Perhaps in favour of better controll !
 

Ambient

New Member
I read the other day about a guy who converted his hummer to run on bio-diesel. He was on his way to a car show and some GM techies were checking out his hummer at the hotel he was staying at. They were quite impressed from what the story said. He supposedly gets nearly double the torque out of it, if I remember right. And the stuff lubricates so well that they could not tell the engine was running.

If you could use a bio-diesel engine to run the generator then you will have a very nice setup.
 
Last edited:

mvs sarma

Well-Known Member
vegitable oils are said to be used for grinding a metal! Such be the case, how bio-diesel stuff could work lubricant? Perhaps the engines life will be on the downturn.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Ambient said:
They are used in the process to keep the bits cool I believe.
Must admit I'm somewhat sceptical about doubling the torque by using bio-diesel - assuming it wasn't the usual made up 'news' in the papers, I would suggest his engine modifications are more likely to be responsible?.

There's an advert currently running on my local radio station for a new diesel fuel - might be Shell? - apparently they have won the Le Mans 24 hour race two years running in a diesel Audi.
 

electric_ride

New Member
Nigel Goodwin said:
Why not just connect the engine to the wheels?, FAR more efficient than using it to power an alternator and charge a battery (both of which make losses).
Because the electric motor is hooked to the trans and then the drive shaft to the differinial . I want the generator to help power the the vehicle and the excess current to charge the batteries while I travel down the road .Plus your way will not work from what I understand.I am charging a bank of batteries . These batteries power the vehicle and I can use a generator for maintaining a certain voltage level and if I'm correct I should be able to get get at least 100 miles per gallon instead of the pitiful 50 miles per gallon a Prius gets. Basically I am going to build alot better hybrid is all and I just need to know if I need to limit my current by using a transformer and using a recitifer if it will clip the sine wave down to a good smooth pattern for dc voltage.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Be interesting to see if you can beat the performance of commercial examples when multi-millions of dollars have been spent developing it.

I would suggest that your generator probably won't have enough power to propel the vehicle, and charge the batteries - except under very specific low load conditions?.

Bear in mind, even if you get 100 miles per gallon, it's not really that - it's 100 miles per gallon AND per battery charge.

Anyway, what you need is an automatic battery charger circuit, but requiring such a high power is what's going to make it tricky.
 

simoin

New Member
electric_ride said "I just need to know if I need to limit my current by using a transformer and using a recitifer if it will clip the sine wave down to a good smooth pattern for dc voltage."

So what is the verdict all you experts what does this guy need to do?

Don't forget from the sound of this guy already has a fully electric vehicle and now wants to modify it into a hybrid, this should not be that hard should it? From my limited understanding of electronics the batteries would only draw as much as they need to keep themselves charged, so you'd be more charging the batteries than running the car unless they were full in which case your engine might pick up the generator as a power source?
 

jpanhalt

Well-Known Member
Most Helpful Member
simoin said:
electric_ride said "I just need to know if I need to limit my current ..."
While I hate to contribute to the plans of someone who wants to pollute the environment more than is necessary to attain his goal of mobility, or to waste energy, or both, the answer is yes. You need some sort of regulator to go from an electric generator to a battery. Otherwise, you will at a minimum overcharge the battery, destroy it, and contribute even more pollution. A simple transformer or rectifier, though, is not the whole answer. The OP should study the voltage charging and regulating circuits of existing hybrid vehicles. John
 

electric_ride

New Member
Can anyone help me with the circuit I would need to have to make this work ? I am not so worried about overcharging the batteries because a 10k generator can not produce enough current to overcharge the batteries ,but it will increase my range by 75 % . Also if Im using less than half the gas that a Prius uses then I can not see how IM a bigger polluter and I am certainly polluting less than a fully gas powered vehicle.Plus if I run out of gas ,who cares I can still go a long way a Prius can go two miles LOL.Is there anyone that can help with this?
 

audioguru

Well-Known Member
Most Helpful Member
Modern hybrid cars use their electric motor as a generator when the brakes are on.
They turn off their engine when it is not needed.
 

Oznog

Active Member
Actually EVs have BRUTAL low-end torque if they have quality (expensive) batts and components. They can totally destroy up a stock rear end. Stock cars converted to EVs by amateurs who know their stuff have broken into the 10's for the quarter mile.

Well got some tough numbers for you.
It's REALLY hard for a generator to compete with a car engine for efficiency. Went through this awhile ago. Car engines these days are hella well tuned. Generators have the unique advantage of running at constant rpm and load, but that was only a big deal when cars were running on carbs which can't respond with mathematical precision like an EFI system. There really aren't many small generators designed for great efficiency, they're designed to be big and cheap and nobody cares.

Bottom line is we ran the numbers, calculated generator head losses, controller losses, and motor losses, and it **might** be slightly better (maybe 10%-15% more mpg) than the car's engine, but more likely less, and certainly can't double your mpg or anything. For one, we didn't take into account that even a 10KW generator is HUGE, heavy, and might need to be pulled on a trailer. Now that's assuming the power won't be stored in the batt. Storing in a lead-acid batt and taking it back out can lose 30% of the energy as "cycle loss" so at that point the budget to compete with the original engine is definitely broken.

And I've also considered top of the line turbines. They may come with substantially better efficiency, but we're talking in the 10%-30% range. In fact that's where the "best case" of minor mpg improvements comes from.

Plus a gen lacks any oxygen sensors, EFI, and catalytic converter. It can produce tens, even 100x the pollution per mile of a modern car! It's probably illegal and certainly not "green". A common 10KW gen is phenomenally noisy and smelly too, I mean it'll get you noticed and not in a good way.

Suggest you go here right away:
http://lists.sjsu.edu/mailman/listinfo/ev

Search the archives to catch up then do some talking. These guys know exactly what backyard EV tech can and can't do. The generator has come up and the numbers just keep pointing to it not being a solution that meets "green" or even fuel-efficiency goals.

Sorry but the "60 mpg Hummer" guy (Jonathan Goodwin):
http://www.fastcompany.com/magazine/120/motorhead-messiah.html

His claims don't hold up to scrutiny. He made a nice EV that is a pretty good example of what amateurs can do. He doesn't present any reasons to justify how he's gonna make a 100mpg 1960 Lincoln Continental- he just says it's a goal. A lot of his other points are totally unrealistic by a long shot but it's sort of a long story why.
 

electric_ride

New Member
Hey Oznog , yeah I have been looking at several things and know I will have losses , I do not plan to using gas though . I do not plan to use the gen all the time either for regular commutes it would just be dead weight , my interest is if I would like to do a few hundred mile trip .If it proves out to be a worthless device on the vehicle the upside would be in case of a power outage I have a way to power the house and garage up.Thanks for the links I will check them out.
 
Status
Not open for further replies.

EE World Online Articles

Loading

 
Top