Search found 741 matches

by major
Apr 12 2019 7:23pm
Forum: E-Bike Technical
Topic: Recommended Soldering Iron for 5AWG?
Replies: 11
Views: 301

Re: Recommended Soldering Iron for 5AWG?

Ever consider a torch?
by major
Mar 30 2019 9:04pm
Forum: Alternative Energy
Topic: Solar Well Pump
Replies: 6
Views: 275

Re: Solar Well Pump

Hi TPA, I live out in the sticks. Need a back-up for my well pump. Don't like gas engine generators. I have plenty of batteries. So I have a number of UPS units which I can use for different appliances. The well pump was a challenge due to inrush or start-up current. It is a single phase induction m...
by major
Feb 24 2019 11:08pm
Forum: Battery Technology
Topic: Could you rate these 18650 cells for me?
Replies: 10
Views: 294

Re: Could you rate these 18650 cells for me?

I was impressed with the NCR18650PF. Tested total of 32. All virtually the same. Manufacturer's spec sheet gives rating of 2750mAh, 2700 min. My charger was only getting cells to 4.05-4.10V which accounts for some slightly low Ah readings. I was able to fully discharge at 10 amps as per spec. At 12A...
by major
Feb 24 2019 5:17pm
Forum: Battery Technology
Topic: Could you rate these 18650 cells for me?
Replies: 10
Views: 294

Re: Could you rate these 18650 cells for me?

I recently bought and tested some Panasonic NCR18650PF GA Cells, new. These were rated at 2900mAh, high drain hybrid, 10A and have a light green wrap and white washer. Attached are my curves.
Pana1thru12at5A.png
Pana1thru12at5A.png (37.49 KiB) Viewed 239 times
Pana1thru8atVariousA.png
Pana1thru8atVariousA.png (38.78 KiB) Viewed 239 times
by major
Jan 23 2019 11:12pm
Forum: Motor Technology
Topic: Air gap, magnet shape, and voltage questions
Replies: 12
Views: 524

Re: Air gap, magnet shape, and voltage questions

On the chart which archer321 posted, I see 48V, 80V, 96V, 330V, & 560V models listed each having different different design constants. With the "air gap" in permanent magnet motors you need to consider the distance of the magnet. Here is some discussion on the subject. https://www.eng-tips.com/viewt...
by major
Jan 23 2019 9:30pm
Forum: Motor Technology
Topic: Air gap, magnet shape, and voltage questions
Replies: 12
Views: 524

Re: Air gap, magnet shape, and voltage questions

There you go. Different voltage models have different voltage and torque constants, so obviously are wound differently. About air gap and efficiency, I'd need to see a lot more details. For me, there are too many unknowns about load and measurements, as well as the motor design and how the modificat...
by major
Jan 23 2019 8:53pm
Forum: Motor Technology
Topic: Air gap, magnet shape, and voltage questions
Replies: 12
Views: 524

Re: Air gap, magnet shape, and voltage questions

I looked at the Heinzmann spec sheet and got the impression that there was a different winding available for 560V.
by major
Jan 23 2019 7:27pm
Forum: Motor Technology
Topic: Air gap, magnet shape, and voltage questions
Replies: 12
Views: 524

Re: Air gap, magnet shape, and voltage questions

APL wrote:
Jan 23 2019 3:03pm
...
And a nice thread on the same info. that I've found useful; http://web.mit.edu/first/scooter/motormath.pdf
...
Use information from that link with caution. I question the accuracy.

Regards,

major
by major
Jan 13 2019 10:33am
Forum: E-Bike General Discussion
Topic: Determining pole count with a voltmeter
Replies: 3
Views: 160

Re: Determining pole count with a voltmeter

... Most likely it's 23 poles; is very common. Hi amberwolf, In my experience, the poles in the motor always come in pairs, N & S, therefore the number of poles is always even, except for the unipolar dynamo which has just one effectively. Could it be the parameter is actually "pole pairs"? Been a ...
by major
Nov 22 2018 12:55am
Forum: Alternative Energy
Topic: How much power to field coils?
Replies: 23
Views: 1088

Re: How much power to field coils?

Also, what is full fielding? Max power to the field coil? It is from a 12V system, right? So 12V or 12.8V would seem to be the upper limit for field excitation. That might be too much. It could be designed, for example, to regulate the field between 5 and 10V. You need the specifications for your p...
by major
Nov 21 2018 4:15pm
Forum: Electric Aircraft
Topic: First-ever plane with no moving parts
Replies: 15
Views: 756

Re: First-ever plane with no moving parts

Looks like the whole thing moves.
by major
Nov 21 2018 4:12pm
Forum: E-Vehicles General Discussion
Topic: Where to get Electrical Steel for Stators?
Replies: 1
Views: 454

Re: Where to get Electrical Steel for Stators?

Hey guys, Anyone know a good source of electrical sheet steel? Right now I'm thinking of contacting a bunch of suppliers on Alibaba and asking for samples. I want to play around with stator prototypes, but it seems super hard to find sheet electrical steel. Hi Alex, Try a Google for electrical stee...
by major
Nov 20 2018 10:21am
Forum: Alternative Energy
Topic: How much power to field coils?
Replies: 23
Views: 1088

Re: How much power to field coils?

I don't know what you are going to use for power input, but let me tell you right off the bat that alternators are meant to run at very high rpm. ... ?? High rpm ??.... Many alternators can produce max output below 2000 rpm . Don't forget the small pulley. The alternator runs 2 to 3 times higher RP...
by major
Nov 19 2018 9:29pm
Forum: Alternative Energy
Topic: How much power to field coils?
Replies: 23
Views: 1088

Re: How much power to field coils?

charlesv842 wrote:
Nov 19 2018 9:12pm
... Not sure what plural field coils are? Attached is a shot of the schematic, let me know if you need more.
Plural means more than one. How many field coils does your alternator have?

I see no schematic.

major
by major
Nov 18 2018 10:55pm
Forum: Alternative Energy
Topic: How much power to field coils?
Replies: 23
Views: 1088

Re: How much power to field coils?

Yes, I read it. I've read other stuff on it too, including a textbook. Still none of it has answered this question. Why then do you use the plural field coils? How many field coils does your alternator have? Over the 100+ years cars have used alternatives there have been hundreds of different alter...
by major
Nov 18 2018 9:16pm
Forum: Alternative Energy
Topic: How much power to field coils?
Replies: 23
Views: 1088

Re: How much power to field coils?

Still dont quite understand. I'm not really clear on alternators yet. As I understand it, the field coils are used in place of permanent magnets (wish they would have just said that in tech school). And the computer can vary the voltage to the coils to change the output current right? So about how ...
by major
Nov 18 2018 2:34pm
Forum: Alternative Energy
Topic: How much power to field coils?
Replies: 23
Views: 1088

Re: How much power to field coils?

I'm using a PCM controlled alternator. And it is internally reg/rec, so nothing to worry about there. It will be hooked up to an SLA an then an inverter. I've seen some other people use AAs for the field coils. But which electrodes do I connect to? Can it be connected continuously? And if there's o...
by major
Nov 17 2018 2:31pm
Forum: Battery Technology
Topic: Large lead acid forklift battery self discharging
Replies: 20
Views: 817

Re: Large lead acid forklift battery self discharging

Hi Gav, Be careful as often the battery weight is critical counterbalance and actually determines the lifting capacity. Of course with a small lithium battery you could just leave the dead lead in there, or replace with concrete. A switch to lithium requires new charger and a BMS. That might end up ...
by major
Nov 17 2018 8:16am
Forum: Alternative Energy
Topic: How much power to field coils?
Replies: 23
Views: 1088

Re: How much power to field coils?

I'm building a generator using a car alternator. I can't seem to find out how much power I need to supply to the field coils or any other details around that. The alternator has a four prong plug. Any help would be great! Hi, You do realize that your typical car alternator has a single field coil o...
by major
Nov 16 2018 3:16pm
Forum: Resources & EV Related Parts and Services
Topic: Reverse Engineered Splines of Various Types
Replies: 1
Views: 299

Re: Reverse Engineered Splines of Various Types

That's interesting. Have more info? Web site? Guys seek these often on diyelectriccar forum.
by major
Oct 23 2018 12:45am
Forum: General Discussion
Topic: Contactor connection pole
Replies: 2
Views: 355

Re: Contactor connection pole

These contactors have a magnetic blowout. That's an internal magnet to direct or lessen the arc. As such, they are polarity sensitive. The direction of the arc diversion is reversed if the current flows the opposite direction. Reverse polarity may just shorten life or worst case will cause the conta...
by major
Oct 19 2018 9:29am
Forum: E-Vehicles General Discussion
Topic: Electric go kart diy [HELP]
Replies: 2
Views: 594

Re: Electric go kart diy [HELP]

http://ddmotorsystems.com/ElectricGoKarts.php.

Or adapt a used golf cart motor and controller or forklift or IUV motor of similar size.

You'll never wheelie in that cart.

Regards,

major
by major
Oct 10 2018 6:45pm
Forum: Large EV General Discussion
Topic: Toro Workman MDE conversion
Replies: 32
Views: 2057

Re: Toro Workman MDE conversion

I think Lithium battery is the way to go. If you get a 200Ah battery, 500 amps is 2.5C. Any decent Lithium cells should handle that. That Sevcon SepEx controller looks like ones I used a few years back, called Millipak, IIRC. I liked them. They pulled hard. Hills should not be trouble. If you are cu...
by major
Oct 08 2018 9:41am
Forum: Large EV General Discussion
Topic: Toro Workman MDE conversion
Replies: 32
Views: 2057

Re: Toro Workman MDE conversion

Hi Rib, Sounds like a good plan. Trading 225Ah of lead-acid for ~200Ah of Lithium. I think you'll be amazed. Anyway, you should plan for a BMS of some sort. That will add cost and complexity. Also, you may need to send the charger in to have the algorithm changed. Member frodus can do that reasonabl...
by major
Aug 22 2018 2:49pm
Forum: E-Bike General Discussion
Topic: celllog not in production anymore
Replies: 14
Views: 858

Re: celllog not in production anymore

miro13car wrote:
Aug 22 2018 1:04pm
...
and I am sure it is covered by patent.
Just looked at one of my cellLog8Ss. No patent # or "patent pending" marked on product, so unlikely it is patent protected.

major