Use this when U don't want to create a short lived topic.

[Lessss]

http://www.perpetualkid.com/index.asp?P ... rodID=1607

LED license plate. Neat. Hmm I wonder if there are any out there that are the size of the entire plate?

[xyster]

These programmable LED license plate frames, window inserts and such will make an interesting adjunct to the common expressions of road rage, such as the perennially popular third finger, horn and "f--- you, assh*le" outbursts -- which as a bicycler who follows the rules of the road unless it is more dangerous to do so, I seem to get a lot of.

[fechter]

I've seen one that goes in the back window of a car that's big, but would only display pre-programmed messages.

Being able to put anything you want is much better. I can see how that will quickly be abused. Great for tailgaters.

[flip_normal]

I went and bought an electric scooter yesterday and it died within 24 hours!

The guy who sold it to me gave me a good deal and is being very helpful but doesn't have much technical knowledge so he asked me to send him an email describing the fault which he's passing on to the manufacturer in China to see whats wrong with it. Since there's a lot of experiance of hub motors and controllers on ES I thought I'd see if anyone here could help find the problem. I can't see the controller on the scooter, it must be tucked away inside somewhere and I don't want to strip it down just yet so here's the message I sent the dealer.

"It was my second trip on the moped after having fully charged it each time until the green light on the charger came on [inducating full charge]. I was about 12km into the trip and I was moving in slow traffic on a level road when the moped stopped working suddenly. Fortunately I only had to push it about 200m home. With the moped on the centre stand the back wheel has resistance when it is turned by hand, similar to the feel of a stepper motor turned by hand, whereas before the back wheel turned smoothly. All the other electrics work (ie. headlamp, horn and indicators) and the power meter is still in the green. I turned the circuit breaker switch off and then back on but that didn't help."

If anyone has experianced a simmilar fault with a hub motor I appreciate any advice and info. Thanks.

Here's a pic. of the scoot.

[fechter]

Sounds like the controller blew a FET.

Does the resistance change when the power is on (no throttle)?

Try the rollback test. Roll the scooter backward quickly and note the resistance. Do the test with the power on and with the power off (no throttle).

Does it blow the main fuse?

With the wheel off the ground, will it run?

If you're lucky, it might just be a loose connection on one of the hall sensors. Trace the wires coming from the motor until they come to a connector. Check the connections.

[flip_normal]

Hi fechter,
no change in rolling resistance whether power is on or off or if throttle is open or closed, just gentle steppy feel like a stepper motor.
motor dosen't run if the wheel is off the ground or not.
can't see a main fuse but there is a circuit breaker under the seat which seems ok on a continuity test.
I'm going to get the ok from the dealer before taking it apart and having a closer look at the controller and wiring. will post any results, cheers.

[fechter]

It sounds like a shorted FET.

If you get the go-ahead to poke around, the same general testing procedure as the Crystalyte motors and controllers would apply.

[flip_normal]

Ok got go ahead to strip out the controller. Now reading up on Crystalyte controllers, will post report and pics as work progresses. Thanks for the pointers fechter.

BTW I recently got hold of 30 IRFB4110's (thanks nemo) hopefully I can use some of these to fix the controller (I was planning to do this mod anyway, this has just made it happen a bit sooner than planned. Assuming they'll fit that is).

[fechter]

I see you're well prepared.

Test the continuity between both power input wires and the 3 phase wires first (battery disconnected). This way you can determine which (if any) of the FETs shorted. There is a possiblility the motor shorted. If this is the case, the cogging will still be noticeable after disconnecting the controller.

[flip_normal]

I found continuity between the black (battery negative) wire and blue phase wire. So it looks like one or all of the five middle FETs IRF1407 has blown.

I found some scorch marks on the underside of the PCB so it appears like there was something in there which shorted the battery out, but it seems as if this vaporized as there wasn't anything loose in there when I opened up the box.

[flip_normal]

There are also some marks on the capacitor near the shunt, see pic. below.

I'm going to replace the FETs with the IRFB4110s and upgrade the capacitors to a higher voltage rating. The battery voltage is 48V at present but I plan to increase that at a later date so I might as well get the controller ready for that while it's out.

Something which didn't help the situation was just sticking the controller to the frame with sticky tape! It'll get fixed back with screws when I'm finished.

The back wheel spins smoothly with the controller out, so it looks like the motor's OK.

[Toorbough ULL-Zeveigh]

translate this?

Haven't forgetten about you.
Finally caught up with my former employer.
I'm just curious what ancient chinese secret you imagined to be revealed cuz it's pretty mundane.

1. Caution read instruction booklet b4 use.
2. Obey traffic law
3. Do daily maintenence
4. Repair all problems immediately

Fickle Finger Of Fate: Keep charging every day
Slash Circle Warning: Do not operate with lo pressure
Circular badge: Quality control inspected by company

Actually it's just good ole chinese philosophy, a general guide for daily living.

[flip_normal]

re. my blown controller:- would it be OK to just replace the five middle FETs (ie. the ones going to the shorted blue phase wire) with IRBF4110's and test the controller back on the moped to see if it works. I don't want to risk blowing a whole bunch of my new FETs by installing them in a controller which may have other faults. Does anyone know if this a sensible way to proceed?

Any advice would be much appreciated, thanks.

[fechter]

I suppose, but if it works, I'd go for replacing all the FETs.

The gate resistors going to the blown FETs are most likely open. The gate driver may be damaged as well, but there's a good chance it will still work.

It's a good idea to test with some kind of current limiting like a 5 amp fuse and with the wheel off the ground. A current limited power supply would be better.

[flip_normal]

re. my blown controller:- IT'S FIXED!

Many thanks fechter and everyone else who's posted all the really useful info that helped me sort it out. I would have done it sooner but I've had a cold all week and soldering FETs while sneezing and coughing isn't recommended.

In the end it all went pretty much to plan: I swapped out the three 1000uF capacitors with new ones and moved them away from potential sources of heat such as the shunt resistor and the FETs, by keeping their legs long I could raise them up and away from these components. The gate resistors were still intact (rated 15ohm on this controller) so I just replaced the five middle FETs, which had the short, with IRFB4110s, plugged the controller back into the moped with a 5amp fuse on the power line and hey presto the back wheel went round when I twisted the throttle. One slight hiccup occurred when I replaced the other 10 FETs and put the controller back in and..... nothing. Fortunately, I soon traced the problem to a dodgy connection with the throttle wires which had one of it's connector pins loose, just pushed it back into the connector block a bit and all done, totally working.

I've now done two runs of about 15 miles each on the moped and all's going fine. I'm sure it feels smoother and a bit nippier than before, it gets up to 30mph quick enough and tops out at about 35mph (eventually) on the flat. I've been riding in traffic with lots of stops and starts and some moderate hills and the hub motor feels only slightly warm at the end of the run. The controller however does feel significantly warmer than I'd like and I'm probably going to do some kind of forced air cooling on it although I might just move it so that it's getting more air flow over it. At the moment the controller is tucked away behind the under seat storage area and stuck to a plate metal box which holds one of the batteries. I'm concerned that the extra heat which this battery is getting will affect it's lifespan and pull the capacity of the whole pack down, so moving the controller to a better location is next on the agenda. The only slight gripe is the poor acceleration as the voltage sags towards the end of the run. I might have alleviated this by putting some solder on the shunt but I didn’t want to pull too many amps through these batteries, they're the silicone ones from Greensaver and I recon they're already operating at or above their recommended amperage rating, which will seriously reduce their life. This will not be a problem however when I replace them with LiFePO4 in the spring, funds permitting! I'll retire silicone batts to a small PV setup I've got planned.

Many thanks again to all on the forum for all the excellent info here. Did I mention ES ROCKS!

[fechter]

Good work.

How warm does the controller get? It really shouldn't be getting too hot, but it does need some air to prevent heat buildup. If the FETs are switching too slow, they could be wasting a bit of power. On the other hand, just the voltage regulator gives off quite a bit of heat, so some cooling is necessary.

It would be nice to know what the current limit is. If your batteries are weak, it's not advisable to increase it. If you got some better batteries, then it sound like you could crank it up

Top speed is a function of voltage, but you can get there much quicker with more current. EVgrin is a function of current squared.

[flip_normal]

Hi fechter, thanks for the compliment. I wouldn't say the controller is getting excessively hot, I can just about keep my hand on it for about 15 secs after a full 15 mile run. The caps are all rated for 105degC so its well below that. I'd just like to keep it as cool as possible since heat stress will always reduce lifespan of components.

A Cycle Analyst is top of my wish list for the xmas stocking so we'll have to wait till then to get a reading on the current draw. The plan is definitely to increase battery voltage My thinking at the moment is tending towards ~66v from 20s LiFePO4. The flat discharge curve and smaller voltage sag should get the scoot to much more where I'd like it to be. That said I'd have to have closer look at the controller to see if it'll take it without going fizz, bang, pop or something Some of the caps in the controller are rated at 63v, some at 50v, one 25v and another at 12v. I may end up putting together a higher voltage Clite type controller with the rest of my FETs using plans from another ES member here in the UK. Then get the range from 15 miles up to ~50 and I'll have a really useful moped, especially if I can figure out how to rig up a method of getting at least a decent partial charge (~80%) in less then an hour whilst out and about, then balance off the cells when doing a full charge when back home. From what I've read here good quality LiFePO4 cells will stay in balance for a few charges without any problems. What do you think of this as a method of providing 36v for the on the fly charging. There's a 36v version of this psu which should be able to put out 13-14 amps, so if I split the pack into 10s sub packs for charging on the fly then am I right in thinking this could work? Maybe the overvolt cut-off could also terminate charge?

This is how my ideas are developing but just for now I'm happy to scoot about town as it is. Even though the moped is bright red the total absence of motor noise when up to speed makes this a very stealthy machine indeed, I just have to ride it as I would a bicycle and assume that at any moment a pedestrian could step out into the road in front of me which is exactly what I'm used to on my pedal bikes anyhow.

I'm really enjoying riding this moped but I wouldn't recommend it to any one who wasn't prepared to sort out potential controller problems and be aware of the limited 15 mile range. The guy who sold it to me gave me a good deal and when I bought it the plan was always to use it as a platform for further developments. The dealer emailed me today asking me if I could fix another controller he's got which isn't working. I advised him that considering the amount of time it took me (over 6 hours) and the cost of the replacement components (£45) and their scarcity then he'd be better off contacting the Chinese manufacturer and resolving the issues with them. They've already said they've had a problem with the controller and have introduced a new one (for more money).

[Lessss]

Woohoo, snow/ice on the ground and the first electric bike foot-ski trip home from work.

[Lessss]

new type of circuit

http://www.informationweek.com/news/har ... t=&isPrev=

[TylerDurden]

new type of circuit

http://www.informationweek.com/news/har ... t=&isPrev=

John Connor commented on Apr 30, 2008 10:33:12 PM
This is the beginning of SkyNet. Soon the T101 model will be developed, based on this design.

No future.

[Link]

Oh weird, LULZ. I just found out about the memristors from my Wii the other day.

[TylerDurden]

bump

[Lock]

new type of circuit
http://www.informationweek.com/news/har ... t=&isPrev=

WOW!
Tks for the link Lessss

"Electronic theorists have been using the wrong pair of variables all these years -- voltage and charge. The missing part of electronic theory was that the fundamental pair of variables is flux and charge. The situation is analogous to what is called "Aristotle's Law of Motion, which was wrong, because he said that force must be proportional to velocity. That misled people for 2000 years until Newton came along and pointed out that Aristotle was using the wrong variables. Newton said that force is proportional to acceleration -- the change in velocity. This is exactly the situation with electronic circuit theory today. All electronic text books have been teaching using the wrong variables -- voltage and charge--explaining away inaccuracies as anomalies. What they should have been teaching is the relationship between changes in voltage, or flux, and charge." - Professor Leon Chua

[deardancer3]

FYI: Los Angeles has to deal with bicycle traffic, considers allowing bikes on sidewalks.

http://www.latimes.com/business/la-me-w ... full.story

Good article to hear the debate from differnt perspectives, and note the current state of legality for bikes on sidewalks in LA county.

I do not know how this would/could/should affect ebikes.

some excerpts:
"... bicyclists in West Hollywood have complained that traffic congestion and narrow roadways in some areas make it dangerous to ride in the street.

After learning that even some members of the Los Angeles County sheriff's bicycle detail were leery of riding in the street, city leaders spent more than a year studying the issue and polling residents and those who work and shop in the 2-square-mile town.

The survey showed that more than half of respondents ride their bikes on sidewalks, even though it is illegal. The idea of sharing the sidewalk between pedestrians and bicyclists was split, with 43.7% for coexistence and 52.7% against it."

Los Angeles County's bike law, which bans all sidewalk riding, also applied to West Hollywood. Santa Monica prohibits it too. Beverly Hills does not permit bikes on sidewalks in its business district.

Los Angeles, however, prohibits sidewalk riding only when it is done "in a willful or wanton disregard for the safety of persons or property." Bikes are banned, however, on Ocean Front Walk between Marine Street and Via Marina in Venice.
---------

Feel free to start a seperate thread if one thinks it is warranted.

(My 1/2 Millon population city allows riding on the sidewalk with no problems. Guess it depends on a bunch of things though)

d

[Lessss]

I wonder how many batteries could fit in there?