EVT "asian" controller

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Jerome
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EVT "asian" controller

Hello,

I read that the EVT controller for Europa and America markets are limited to the 30mph speed. The asian version allows to reach a slightly higher speed. I suppose buying an new asian EVT controller would be very expensive and I suppose the only difference between these controllers is just a chip whichs contains the throttle policy.

So my question is : do you know if it's possible to get the asian countries chip to upgrade our restricted controllers ?

Jerome

reikiman
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Re: EVT "asian" controller

I doubt it. I've talked with Todd @ electric motorsport (.com) a few times and watched him open up the controller a couple times. You've got a bunch of chips soldered on a board. Okay, if your soldering skills are good enough you could do it ... but the key would be getting the chip(s) and EVT probably does not distribute the chip(s) separately but probably only distributes the controller as a replacement part.

- David Heron, http://davidherron.com/

- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
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Jerome
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Re: EVT "asian" controller

It's very strange because I saw some pictures of the inside of the controller. There is only 1 programmable chip (from atmel) and it isn't soldered. It's just plugged in.

Pictures available here :

http://vehiculeselectriques.free.fr/Forum/viewtopic.php?t=1425

reikiman
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Re: EVT "asian" controller

Hmm, it's been 3+ years since I saw the innards of the controller.

Is the chip from atmel a FPGA or EEPROM or something that's programmable? If so you'd need a compatible programmer, and the coding to program into the chip, and a source of compatible chips.

BTW, your link went to a login page and I'd've had to register to view the pictures.

- David Heron, http://davidherron.com/

- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
- Electrified Electra To

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Re: EVT "asian" controller

Jerome,
The link doesn't seem to work, if your not a member.
Can you upload them to your http://visforvoltage.org/user/190/imce and then post them?

Peace Out, ;)
Gman
Jerome, your encouraged as a community stakeholder to share your preferred future vision of our growing community http://visforvoltage.org/forum-topic/our-community-vision/330-it-seems-well-be-here-awhile-what-your-vision-future-

`

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Jerome
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Re: EVT "asian" controller




Do you see them ? I have a programmer.

Fechter
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Re: EVT "asian" controller

If you got your hands on one of the asian controllers, you could possibly read the chip and make a copy of the code. Then it should be possible to re-write the program on a new or existing chip.

Another fun thing might be to try and just read the existing US version chip and see if you can make any sense out the code to make your own tweaks.

Once the code was figured out, then you could sell upgrade kits.

Jerome
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Re: EVT "asian" controller

Well it's not so simple. The chip seems to be a micro-controller and is probably protected against copy.
Is there an known ev community in Taiwan that could help ?

Kmullee
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Re: EVT "asian" controller

Have you guys thought about using a logic analyzer on their controller chip and using a pic microcontroller to replace it?

Keith
2006 E-Max sport @ 60v

Keith
2006 E-Max sport @ 60v
http://keiths-evs.blogspot.com/

Fechter
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Re: EVT "asian" controller

The other way around it is to "spoof" the signals going to the chip. It must have a sensor somewhere to provide a speed input, so it may be possible to alter the encoder or signal to fool the controller into thinking it's going slower. Likewise, there must be a current measuring shunt or hall sensor that could be partially bypassed to increase the current limit (if you wanted to do that).

I seem to remember some satellite TV cards that were copy protected, but hackers found a way to glitch the chip into reading and writing. There's always a way.

Patrick
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Re: EVT "asian" controller

Hey all:

Let me throw in my two cents worth here.

The Atmel is an MCU (don't know what model), and has on-chip programming. This may or may not be copy protected - depends on the chip and whether they chose to implement that. My guess from the design era is that it is not, but that is only a guess. IF not, simply pull one and copy it. You'll probably want an Atmel development environment and burner, maybe $500 - $1000. Then you could, as Fechter says, sell reprogrammed chips. It would a be a ton of work, and get a 10% increase (from 30 to 33 mph) in speed.

The EVT does not use speed encoders - it's all about current. Fooling the current sense is probably the easiest. However, when you do this, you increase the I2R losses (i.e. heat!) in the motor. EVT motors DO NOT tolerate this well. I have seen more than one leak goo (melted compounds) out the seam from over heating. So, a 10% increase is OK, but more than that and you are pushing it.

Increasing the voltage is much better, but still dangerous. EVT motors can be run at 72 volts, and perform well - over 50 mph. There is still the issue of overheating, and that needs careful control. If you live in flatland, and have a light touch on the throttle, you should be ok. Take that very same bike and use it San Francisco - you'll be pushing it home. I don't see a way around this problem - the motor has design specs, and when you go outside the envelope, you're courting meltdown. An over volted, current limited (e.g. 80-90 amps) model probably has good life on the flats. But hills are the same as sustained acceleration, and the motor will suffer.

In short, you can get a decent increase in speed safely. You cannot get a decent increase in torque without drastically shortening the life of the motor. I haven't run an instrumented EVT in hilly territory, so can't give quantized results. They aren't the best hill climbers to begin with, but if you have a way to monitor motor temps you'll be way ahead of the crowd - especially those that are pushing their bikes.

Patrick

Jerome
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Re: EVT "asian" controller

That's an interesting idea because there is no need to look for an "asian" controller then. Unfortunateley I can't help achieving this. But I think there are people here ready to pay few bucks to have an unlocked/improved EVT controller.

andrew
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Re: EVT "asian" controller

Is there a way to improve cooling of the motor?

A few random insane ideas that just popped into my head:
Add seals and fill the motor cavity with a light oil. This will raise the thermal inertia, and help conduct heat to the periphery.

Use a high-pressure pump, maybe a fuel pump from a car, to spray a light mist onto the motor periphery.

Simply drill a few holes in the motor where permitted.

Drill and tap some shallow holes into the motor casing and bolt on aluminum fins. Or very carefully arc weld on small steel fins.

Use a small refrigeration unit to pre-cool the motor very cold before riding. This will lower the resistance.

Unbolt the rear wheel and stick it in the freezer with the setting as cold as it goes before riding. Use and Anderson connector to quickly disconnect/reconnect wires. Consider adapting/designing a quick release system.

Rewire the motor. A thinner wire will result in a higher torque constant and lower velocity constant.

Clamp on a plastic oval piece around the motor and fill it with ice. Ice is cheap, just fill it up before you ride. You'll need to have it clamp tight and seal well or you'll get ice flying out.

Machine the rim off, and weld on a smaller rim (if there is room). Reducing the rear tire size will increase the motor speed, allowing for lower current and higher voltage input to output more power at a give speed.

Find a custom tire of some sort that is smaller than stock to fit on the rim.

If you really to go nuts, use liquid nitrogen/dry ice to pre-cool the motor. Again you'll need some sort of bolt on oval to form a cavity around the motor.

Less extreme is to use salt and ice (both cheap). The salt will cause the ice to melt at a temp below freezing. The resulting salt water can be far below 32 degrees F, and help pre-cool the motor quickly.

Spray <32 degree salt water on motor in above idea with fuel pump.

If there is not much room for ducting air, then duct pre-cooled air through the motor through the hole used to run the wires. Pre-cool the air by sending through a radiator submersed in sub-zero salt water, or liquid nitrogen.

Somehow affix a sprocket to the motor casing, then use this in conjunction with another motor via chain drive to help with the load.

I know these ideas are much more novel than practical, which is why they'd be neat to try.

[url=/forum-topic/motorcycles-and-large-scooters/587-my-kz750-electric-motorcycle-project]KZ750 Motorcycle Conversion[/url]
[url=/forum-topic/motorcycles-and-large-scooters/588-fixing-my-chinese-scooter]900 watt scooter[/url]
Pic from http://www.electri

mf70
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Re: EVT "asian" controller

Somehow affix a sprocket to the motor casing, then use this in conjunction with another motor via chain drive to help with the load

This is the one I was thinking about. A supplemental motor would let you set up gearing that would improve performance in the range you were most affected by. In my case, my Yonkang Crown could use help in the 0 to 12 KPH range. A "boost" motor could be geared to help in this range, with an overrunning clutch to remove drag above that speed. Control could be a relay switching in full pack voltage to the boost motor. Probably 500 watts, properly geared, would make a big difference in low-end acceleration.

MF

Jerome
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Re: EVT "asian" controller

Just a though : do you think it is possible to just replace the front wheel with a second evt hub motor ?

Jerome
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Re: EVT "asian" controller

Hi,

I got an interesting information about the controller. The output voltage of the controller is 41.5V only, not 48V. We suppose EVT limited the motor voltage to reduce the top speed for european and us markets.

Jerome

fixitsan
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Re: EVT "asian" controller

How are you measuring the output voltage ?
If it's only by using a voltmeter you might not see the whole signal. My suspicion is that the signal is pulse width modulated, and what you're actually measuring is the average voltage.

It ought to be possible to either bypass the output from the controller which switches that array of FET transistors screwed onto the heatsink so that they are always on 100%, or fit a large realy which bypasses the output from the Fets completely and puts the motor in direct drive, maybe controlled by a switch whcih only actuates when your throttle reaches the end of it's travel.

Good Luck !

Chris

Jerome
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Re: EVT "asian" controller

The voltage was mesured using a fluke scope. The signal is modulated between 20V and 41V.

fixitsan
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Re: EVT "asian" controller

How much current is being drawn ?

Thiose particular mosfets have an Rds of 0.023 ohms. if they are configured as a bridge then you have two in series with the motor, 0.046 ohms.

If the motor drew 40amps under full load you lose a couple of volts there.
There may also be a shunt resistor in curcuit mesuring motor current, you have voltage drop over the cables if they are rated too close to the nominal current, and so on.

Does the voltage you see drop significantly under load ?

I'm just tryiong to point out why the voltage coming out of the controller is lower than B+
The limiting factor may not be a piece of hardware but may instead be the maximum duty cycle of the PWM signal.
I actually doubt there would be a voltage limit through hardware, if the motor drew a peak current of 40Amps and they drop 8 volts over a resistor at 40Amps it would need ot be rated for 240W !

There are other ways to limit the current in hardware but it would be somethign which generated heat, and wasted power.

Of the motor controllers I've worked on, and built there are very few exceptions in design whcih mean you cannot bypass the output switching section directly. If one wanted to be extra safe then you could add a relay which only actuated at the end of the control pot's travel, disconnecting the controller from the motor and connecting B+ directly to the motor to get full power.

The suggestions that you could hack the software are valid, as long as the security bits haven't been set in the Micorcontrollers. Out of interest it might be possible to know which type of microcontroller you don't have based on the position of the power pins which supply it. Pic power pins are in a distinctive location, Atmel and other 8051 variants have a similar one to each other but different to pic.

Once you have traced out the hardware it is probably going to be easy to write your own code for a microcontroller and do away with the micro which came with the controller altogether !

Chris

Jerome
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Re: EVT "asian" controller

The motor eats more than 100 A at full load. And voltage never goes further than 41V whatever the load you get. Voltage seems stable. I'm sorry I'm pretty ignorant about controllers !

fixitsan
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Re: EVT "asian" controller

Have you managed to establish that the non-limited version outputs more than 41V yet ?

The way that most modern DC motor controllers work is through the use of pulse width modulation, PWM.

Simply put it is a scheme whereby the voltage is switched on and off rapidly at regular intervals. What the motor receives is the average voltage, so if the peak voltage is, say, 20V, and the switching is at a 50% rate then the motor gets 10V

Your controller is switching between 20V and 41V, that's unusual but acceptable. If the switching is done such that the off-time between pusles equals the pulse length, 50% rate, then the motor gets the average which is about 30.5V

The most used way to limit speed is to ensure that the switching circuit never switches at 100%, or in other words is always switching on and off quickly. To limit the voltage at 80% the controller pulse scheme will be that in every switching cycle the output is on for 80% of the time and off for the rest of the time.

Each switching cycle could last less than 1mS, but the real length of a switching cycle is 1/frequency. Some controllers switch at such a low frequency that you can hear them, using the motor as an accoustic coupler to make the noise. If the controller switches at a frequency of above about 15kHz you generally won't hear it.

What I was suggesting earlier was that to remove the effect of the limit without affecting the controller you could just righ up a bypass whcih comes into play only when the throttle is set to it's maximum position, whereupon the motor is connected directly to the battery

At 100Amps, and at 0.043ohms switching element resistance, there is a loss of 4 volts, and probably there are other losses to consider at such a high current, such as connector losses for example.

Chris

Jerome
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Re: EVT "asian" controller

Thanks for your comments. They are all very interesting. I understand that the voltage drop is probably not a wanted behaviour and the limitation should be implemented with the duty cycle. I don't know the asian controller, I was just told that asian EVT are going faster than ours.

The bypass method is a nice idea and will give a good boost to the scooter. I just wonder if this is really safe for the motor. Controller is limiting the current and the bypass will disable this security. Another problem is the throttle command is inside the EVT controller so I don't see a simple way to command the bypass relay.

Jerome

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Re: EVT "asian" controller

Patrick,

you all have any of the ungoverned Asian controllers in stock over there at Electric Motorsport? How about setting me up with a wiring harness and extra battery for the 60volt mod?

Here's a question: I'm currently using three Powercheqs for a BMS on my EVT 4000e (four batteries at 48v). If I install the Electric Motorsport 60 volt mod (48v to controller logic circuits, 60v to power circuits), and I am charging the existing 48 volt pack and the new 12 battery separately, can I keep the Powercheqs in place as is to balance the 48v charging?

-Crusher300
Silver EVT 4000e San Mateo, CA

-Crusher300
Silver EVT 4000e (60 volt) San Mateo, CA

Jerome
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Re: EVT "asian" controller

I don't think there is any problem keeping the powercheqs.

Patrick
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Re: EVT "asian" controller

Crusher300:

A happy coincidence - I haven't checked this board in a few months. Here's what I've got:

No asian controllers at Electric Motorsport. Nice if we did - I'd like to pull that Atmel and see what we could find out. Though I have run current vs. speed on some bikes, I've haven't put the motor on a scope, so I cannot give you details on how the PWM is implemented. In fact, I haven't spent any time on EVTs since December; I've focused on the Oxygen, and we've gotten these up to 35 mph.

Yes, the Powercheqs can remain in place - no problem there. If you go to 60 volts, you'll have a separate charger for the extra batt, and all will be in harmony. Good that you have a 4000; you'll need the space (losing the under seat storage) for that batt. Here comes the disclaimer: I don't remember how/where you mounted the 'Cheqs. If memory serves, you've got them on the rearmost bracket under the tail, and retained the under seat storage.

Now for the delicate part. If you pull the storage unit, how big a battery can you fit? Of course you'll want another EB-50 - do you have the room? I think you do, but am not sure. I also think you'll have enough room left over to fit a 6 amp Soneil on board for the extra batt. As far as the harness goes, we usually custom make these to fit the exact battery configuration. I think I could make a generic one, but then you'll end up with some extra length in the cables. You'll also need to pull most of the plastics to fit everything.

That being said, I think it would work well for you. The 60 volt mod will get you about 38 mph, much better than the Asian controller; and if you are moderate (keeping acceleration down, and limiting your speed to about 30 mph) you might get 50 mile range (you're a big guy - my calcs say that theoretically one could go 60 miles). My personal opinion is that a 60 volt 4000 is the sweet spot for price/performance - if you live in flatland. Grind it up long hills and it won't last, IMHO. And no warranty, of course.

Questions?

Patrick

Jerome
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Re: EVT "asian" controller

Patrick just a thought. Maybe you have a spare / broken us controller. So it would be possible to see if we can read the chip. After that disassembling controller code and adjusting the settings is possible. I don't feel confident enough to dismantle my own controller sorry.

Patrick
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Re: EVT "asian" controller

That's a good idea. There is a broken EVT controller around somewhere, but I think it's buried behind about 15 feet of other useless junk. I'll ask around and see if we can find it.

Patrick

Crusher300
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Re: EVT "asian" controller

Patrick,

I called Electric Motorsport, but they said you wouldn't be in this week. I sent an email to the sales address. I'd like to get going on the 60 volt mod. I put the PowerCheqs in the tail section and have full under-seat storage space available for the additional battery. I would prefer an additional EB-50 if it fits. Do you all stock a 12 volt charger for the additional battery? Can you get me a price quote for the harness, EB-50 and charger? Thanks!

-Crusher300
Silver EVT 4000e San Mateo, CA

-Crusher300
Silver EVT 4000e (60 volt) San Mateo, CA

Patrick
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Re: EVT "asian" controller

Hey Crusher:

I'll be in tomorrow, and talk to Todd. You'll be hearing from us.

Patrick

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Re: EVT "asian" controller

Hello, I am a new member from the great White North (Saskatoon, Saskatchewan). I ride an 4000e (today I was riding in the snow). I am a mechanical engineer that likes to play with things and sometimes I pretend to be somebody who knows something about electronics (just enough to make things smoke). My scooter is an American model which is speed limited. I just want that extra 6 kmh to keep up better with traffic.

Last fall, I instrumented my scooter with an onboard data acquisition PC. I ran around the city and measured voltage and current while I was riding. Here's a short summary:

Peak current during full throttle accel (performance mode) -- 200amps
Steady-state current at about 50KMH -- 30amps
Energy consumed during one acceleration from zero to 50KMH -- 25 W-hr
Average motor power over about 10 minutes -- 1100 W

Does this agree with anybody else's data? If anybody would like to see the graphs -- I have them all in XL. I'm not convinced of my current shunt was working properly -- I think it was heating up and my peak current could be a little high.

Anyway, some thoughts:

I don't think it makes sense for the controller to use current to limit the maximum speed. Maximum current occurs at low speed accelerating. Anyway, the only way to push more current into the motor (given the back-EMF as the motor increases in speed) is to increase the voltage.

If I have some time tomorrow -- I'll run the output of the controller into my data acquisition (I can sample at 10,000 Hz which should be fast enough to catch the PWM cycles) and see what's really happening.

Does the 60 V mod work for the speed limited US controller? I am guessing it would -- the PWM "on" portion would be at a higher voltage and the average therefore higher for the same duty cycle. Is this the way it would work?

The 60 V mod -- is this simply supplying 60 V to the input of the controller? All the time?? or just a boost button?

Rick Retzlaff

Patrick
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Re: EVT "asian" controller

Rick:

Your peak current looks high to me. My memory is that the 4000 pulls about 120A peak, but I could be wrong. My notes say that at 50 kph, a 60 volt mod is pulling about 20 amps. Yes, you'd pull more amps at the stock 48 volts.

Yes, the 60 volt mod works on US models of the EVT. Do read the caveats about using this mod in hilly territory. Your thoughts about how it works are bang on the money. The 60 volts is supplied to the controller all the time. N.B. - you've got to feed the rest of the bike with 48, so you don't blow it up.

Best,

Patrick

Patrick

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