DIY Electric Car Forums banner

1 - 20 of 21 Posts

·
Registered
Joined
·
7 Posts
I emailed them and got this response.

Thank you very much for your inquiry and the interest you have expressed in our technology. We typically develop and produce our electric propulsion systems as part of large scale hybridisation projects – with customer specific adaptations – for industrial or government clients. Therefore we do not have any standard components for which I could readily send you a quote or user manual.

If you are looking for a long term development partner, I would be grateful if you could send us a rough specification of the application you have in mind to allow our expert to evaluate how best to be of assistance to you.

Kind regards

Sonja StammwitzAssistant to the General Manager

L-3 Communications Magnet-Motor GmbH
 

·
Registered
Joined
·
780 Posts
I emailed them and got this response.

Thank you very much for your inquiry and the interest you have expressed in our technology. We typically develop and produce our electric propulsion systems as part of large scale hybridisation projects – with customer specific adaptations – for industrial or government clients. Therefore we do not have any standard components for which I could readily send you a quote or user manual.

If you are looking for a long term development partner, I would be grateful if you could send us a rough specification of the application you have in mind to allow our expert to evaluate how best to be of assistance to you.

Kind regards

Sonja StammwitzAssistant to the General Manager

L-3 Communications Magnet-Motor GmbH
In other words: "beat it you DIYer. If you're not a huge contract I don't want to talk to you". I bet the Linux developers got this same line many times before. Now everybody's kissing their *&$# begging to get on the Linux bandwagon. We have the Soliton guys and several others providing DC systems, HPEV for AC and some Chinese suppliers for BLDC. I'm sure others will jump in soon enough to give us a nice high power AC package while we watch those "big customers only" companies go down in flames.

JR
 

·
Registered
Joined
·
81 Posts
it just means one of the supply guys around here would have to take em on, see if buying a bulk pile of them would be worthwhile or cost prohibitive.
 

·
Registered
Joined
·
12 Posts
What companies like that fail to realize is that 70% of business and the US economy are small business, and that principal of not doing business with small business or even individuals will not usually pay out in the long run. If they don't diversify and lose their 1 or 2 big contracts, goodbye. Will enjoy seeing them go down in flames.

I had a similar experience with a US based battery company. Guess I'll be going Chinese then.
 

·
Registered
Joined
·
1,466 Posts
My dad and I worked for A O Smith and they made about 90% of car , light truck , heavy truck frames . They were making so much money on frames that they let other products go . Then the big 3 started to go away from frames . SOL
 

·
Registered
Joined
·
239 Posts
My dad and I worked for A O Smith and they made about 90% of car , light truck , heavy truck frames . They aere making so much money on frames that they let other products go . Then the big 3 started to go away from frames . SOL
The inventor of the digital watch tried to sell the rights to Timex and others and got sneered at repeatedly. When it finally hit the market he buried them. When you're big enough and rich enough there is no longer any motivation to go after any risk at all. The world is full of ex-buggy whip manufacturers. The life cycle of all businesses goes from zero value at start-up to zero profit (at sell-out/sell-off). Once the management goes away from the concept of continuous improvement (Kaizan ? sp.) the fix is in. Everybody just wants to be a wall-street banker. They don't talk about their performance ability anymore.....just talent, the "new" bonus justification.
 

·
Registered
Joined
·
1,466 Posts
in the case of diy Ev's all they can do is mass market , drop the price to out compete diy'ers .but that makes more parts and cheaper for us to build . So there left with make a law to stop this dangerous diy group.
 

·
Registered
Joined
·
5 Posts
wat is the improvement of an dc to ac inverter setup over the normal dc to dc current controllers / forklift type motors out there at the moment , i only found out there doing these things as homebuilds and try to find out wat the advantages are
they look to have a lot more parameters to get right or they blow up
do the ac motors use less current , run cooler , have better power , are they cheaper , are they smaller ?
 

·
Registered
Joined
·
571 Posts
wat is the improvement of an dc to ac inverter setup over the normal dc to dc current controllers / forklift type motors out there at the moment , i only found out there doing these things as homebuilds and try to find out wat the advantages are
they look to have a lot more parameters to get right or they blow up
do the ac motors use less current , run cooler , have better power , are they cheaper , are they smaller ?
You will find endless discussions from the subject if you search, but in a nutshell:

- Regen, which gives real range and efficiency improvement in stop&go traffic and/or mountains, but not so in flat areas & highway drive (you can get this with some DC motors & controllers too, but not with the "typical" ones.)
- A bit better efficiency, maybe 5% more range (this also means less heat)
- No need to change brushes & clean brush dust
- Possibility to run to high enough RPM to ditch the transmission or lock it to single gear
- No TECHNICAL reason why it would be more expensive anymore due to improvements in semiconductor manufacturing; but the market responses at limited speed, hence, cheap DIY AC solutions are still scarce. And AC has a "premium technology" extra on its price tag, even if this is not based on any real cost. You can except a change in a few years because many people are working on this behind the curtains. When it happens, DC will practically disappear as has happened on many fields. Until now, DC has been an easy to pick solution "that's already there and works well enough".
 

·
Registered
Joined
·
5 Posts
hmmmm 5 % more efficient is less than i figured from all the whooha on the forum , regen in the netherlands wouldnt work as its as flat as a snookertable
i been trying to understand the principle of converting dc to ac , its hard for me though and it allso looks like its mush more sensitive to outside electric and radio noise
looks like i be sticking to the dc idea for now

thanks for the explaination i couldnt find it when i did a quick search on here did found about 4 inverterprojects in various stages of completion
 

·
Registered
Joined
·
571 Posts
i been trying to understand the principle of converting dc to ac , its hard for me though
The "basic" case is simple; but to extract all the efficiency and power, it gets a bit complicated indeed. But it is mostly a "software" like thing so it's easy to duplicate once done right.

(Note that a DC motor is internally an "AC" motor and it just has a mechanical DC to AC converter that is synchronous to the actual rotor speed. The inverter does the same but electrically which opens some new doors compared to the simple mechanical solution.)

and it allso looks like its mush more sensitive to outside electric and radio noise
LOL, this is nonsense. There are all kind of myths...
 

·
Registered
Joined
·
5 Posts
i seen it on some of the vids and talk on the forum , in the clips it even shows up on the scope when they testrun the stuff , sumting to do with the placement of the different stuff on the board and possibly some of the wiring
 

·
Registered
Joined
·
1,696 Posts
I ran a scope over my car and the AC motor leads were the only spot I found any interference. That was from the variable frequency current to the motor.

My radio operates clearly.

I run a lap top computer with in 1 meter of them and with no problems.

I do not have to keep carbon dust cleaned out nor have to resurface the commutator on my AC motor either. It is good for the service life of the bearings.

It is flat here in Arizona also. I like the regen braking and I will never need to replace my brakes....ever.

Most major car makers all use AC motors.

Yes I paid more than a DC system, but I'm good with that.

Miz
 

·
Registered
Joined
·
5 Posts
maibe we need to talk someday when theres a good program and controller for my project (thinking microcar sumtin like a smart car running 96 volts or little more )

i been looking further intoo the whole conversion in general (prices for lit ion batteries are huge but lead acid or sealed lead batteries should do fine for the few mile to and from work) and the goverment aproval (new papers that say electric car) for driving the roads legal here , the test for radio disturbance is actually a new and big thing in the aproval , the want a certificate from some known testfacillity to proof it doesnt interfere with any radio frequencies and to have youre car tested isnt cheap , even some factory build electric cars have trouble getting that certificate

would making a totaly freestanding / rubber insulated faraday cage from copper mesh around the controller motor and powercables work , or how would someone go about solving this problem even if its only temporarily till after the test and aproval ?
 

·
Registered
Joined
·
3,141 Posts
The only source of RF in an AC system is the inverter itself, which is usually enclosed in a NEMA steel box. Commercial VFDs probably have been tested for RFI and that may be enough for compliance. The leads to the motor can be twisted to reduce EMI emissions and enclosed in flexible conduit or braided shielding. The motor itself is usually totally enclosed so emissions should be minimal. :)

Brush type DC motors also use choppers and PWM to drive the motor, and the high currents require larger conductors which may not be so easily shielded. Most problematic, however, may be the commutators, which are subject to arcing and are often somewhat exposed, so I would expect RFI to be even worse, and the variability of the effective commutating frequency may make it more difficult to control. ;)
 

·
Registered
Joined
·
287 Posts
To add to whats been said; I also use an AC motor, but with an industrial VFD. (ABB ACS601) Since it has built in filters (DC bus inductors), there is slight noise in the radio (barely audible hum on AM only), but for the most part it all works fine. I use the DTC motor control instead of PWM. I find PWM drives tend to cause a little more interference. I have no problems with control signals or any kind of interference that might cause the motor to act unexpectedly
 

·
Registered
Joined
·
571 Posts
Ah, as for this:

it allso looks like its mush more sensitive to outside electric and radio noise
I thought it was about controller malfunctioning due to interference caused by other electronics nearby, not about the controller causing interference to other devices.

Yes, RF emissions caused by the drive system can be a real problem, but somewhat equal to both AC and DC controllers as they are similar PWM controllers and work with similar switching frequencies. DC motors also have brush arcing as an additional RF emission source.

It may be a problem if strict regulations are in place as in some countries, and if the particular product is not designed and tested under such regulations.
 

·
Registered
Joined
·
5 Posts
just got a quote for the rf test for a single vehicle ...... 7500 euro's ....... zoeink :eek:

best thing for me i think is to buy a ready tested kit with certificate and go straight to start
one of those is about 10000 euro's wish would be sortah the same price as the homemade stuff and the RF test combined
 
1 - 20 of 21 Posts
Top