My e-Brompton: Tongxin/Nano pulling steady at 360W+

NRG

Esteemed Pedelecer
Oct 6, 2009
2,592
10
Ask him, I ordered a controller a few weeks ago and it was sent from a London postal address...
 

Keithdrengen

Pedelecer
Jan 26, 2010
27
0
"small 10A programmable brushless sensorless controllers with 3-way "power" switch"
I can´t find any such (36v) controller on his website.

"Ask him"
How do I ask him? I cant find an email adress to get in contact with E-crazyman

Carsten J
 

daniel.weck

Esteemed Pedelecer
Aug 8, 2009
1,224
1
"small 10A programmable brushless sensorless controllers with 3-way "power" switch"
I can´t find any such (36v) controller on his website.

"Ask him"
How do I ask him? I cant find an email adress to get in contact with E-crazyman

Carsten J
Try this:

ecrazyman@gmail.com

...or otherwise via the eBay messaging system.
 

daniel.weck

Esteemed Pedelecer
Aug 8, 2009
1,224
1
It's been a while since I last used the 36V Bafang "8-Fun" SWXK 255rpm hub motor (rated 250W) which I have laced into my 16" Brompton wheel. Instead, I have been riding with the much quieter 36V Tongxin 190rpm (rated 180W). Both motors are brushless no-Hall-sensors with 3 phase wires (I use the same controller for both), but the Bafang is nylon-geared unlike the Tongxin which uses friction rollers rather than permanently-interconnected planetary gears (so in theory, the Tongxin is more likely to slip under heavy load).

Recently, I configured my small 6-FET 15A controller (Infineon XC846 chip, EB806 board) to handle higher currents, and the Tongxin is happily driving the wheel at 12A continuous for a few minutes (max assistance in uphill rides). Of course, most of the time the e-assistance reaches 8-9A max, which is a safer peak power. However it is good to see that this perky little Tongxin can handle the torque without slipping. My guess is that the 190rpm model is really geared for larger wheels, so maybe the elliptical friction gear demultiplication is such that I am loosing top speed in favour of reliable low-end torque (which is fine by me, as I only need assistance at low speeds).

I have configured my 3-speed switch so that the middle setting is safe for the Tongxin (9-10 amps max), the low setting is good for walking alongside the bike (e.g. when pushing it uphill), the high setting is 100% (basically, whatever phase/rate current I set in "KeyWin eBike Lab" ParameterDesigner.exe)

I still use the same two batteries: 10Ah LiFePO4 Li-Ping "big" pack + 2.6Ah A213 "mini" pack. Both handle over 1C discharge rate without complaints.

I am still trying to figure out what the stock settings are for my controller, any idea? (I've been searching on endless-sphere as well)

Cheers, Daniel

 
  • Like
Reactions: schiller

jerrysimon

Esteemed Pedelecer
Aug 27, 2009
3,292
112
Cambridge, UK
This old post brings back memories Dan.

I use those controllers all the time for my Tongxin and Keyde motors. On the ones I get you have to add wires to program them (and will need a USB programming lead) and pick up the other board options like cruise control and power level options, unless e-crazyman sells them pre modified ?

The alternative is to buy the more expensive lyen versions which come with programmable lead and other options ready fitted/enabled.

Regards

Jerry
 
Last edited:

daniel.weck

Esteemed Pedelecer
Aug 8, 2009
1,224
1
Yes, good memories!
Experimentation, technical apprenticeship ... still learning though ;)

Both my controllers are based on the EB806 board (precursor to EB206 which comes with an upgraded Infineon chip), so the programming options are limited. However, I get everything I need:

- Speed restrictor (extra cables soldered to circuit board + connector, to comply with legislation ... I'm not actually using this as my full assisted speed is physically limited by the size of the wheel and the motor's max RPM anyways)

- 3-speed switch (I use this all the time when I ride, alongside my Brompton's 6 "physical" gears)

- Throttle control (I use this to quickly get out of the way at intersections, from cold start)

- PAS / pedal velocity sensor (I rely on this most of the time, allowing the controller to adjust the e-assistance without me having to "think" about it)

The problem with the USB/TTL (or RS32) protocol is that ; as far as I know ; data can only be written to the chip, it cannot be read / dumped. So I wasn't able to compare the stock settings with my own.

At the moment I use 16A rated current (which is the max DC current, effective when cruising along), and about 2.5x that value for the phase current (effective in burst mode, when starting the motor).

These parameters are to be interpreted in the context of the controller's hardware though (MOFSET rating, etc.), so they are representative of the actual current flowing from the battery to the motor under load, with some arithmetic formula adjustments. For example, my Cycle Analyst never shows 16A, more like 12A peak.

There's an "open source" controller sold on endless-sphere, but it's 300 USD, not worth it for a low-power application like our e-Bromptons.

Cheers, Dan

This old post brings back memories Dan.

I use those controllers all the time for my Tongxin and Keyde motors. On the ones I get you have to add wires to program them (and will need a USB programming lead) and pick up the other board options like cruise control and power level options, unless e-crazyman sells them pre modified ?

The alternative is to buy the more expensive lyen versions which come with programmable lead and other options ready fitted/enabled.

Regards

Jerry
 

daniel.weck

Esteemed Pedelecer
Aug 8, 2009
1,224
1
-- ParameterDesigner.exe settings for my controller --

At the moment I use 16A rated current (which is the max DC current, effective when cruising along), and about 2.5x that value for the phase current (effective in burst mode, when starting the motor).
Today's ride (as indicated by Cycle Analyst): 15km => 2.8Ah consumed from my 10Ah LiFePO4 battery.

http://www.pedelecs.co.uk/forum/threads/diy-stage-2-received-li-ping-lifepo4-battery-photos.4734/page-2#post-216434

It's quite hilly around here, and it was windy today. Max current draw was 15A, and I could effectively see 12A displayed on the CA (when battling up hills ;) ). The Tongxin motor didn't slip at all at 400W output, but I am aware that the repeated strain (torque) on the motor's alloy axle / wall is probably not recommended (judging by forum photos of fractured sides).

Anywhoo...great solid unit this 190rpm Tongxin!! :)
 

jerrysimon

Esteemed Pedelecer
Aug 27, 2009
3,292
112
Cambridge, UK
Dan they now do a 290-300RPM version in 28h and 80mm wide. Perfect for they Brompton :)

Jerry
 

daniel.weck

Esteemed Pedelecer
Aug 8, 2009
1,224
1
Dan they now do a 290-300RPM version in 28h and 80mm wide. Perfect for they Brompton :)

Jerry
Nice for extra top speed! I would love to compare with the low-end torque of my 190rpm model. In case I am wrong in my assumption about mechanical gearing demultiplication (relative size of friction rollers), then the technical difference to achieve the various RPMs must be in the internal windings.

How many $$ for a fully-laced Tongxin 300rpm (28h)?
:)

Dan