Modifying a shunt with controlled results

Get all your technical information about electric bikes here.
John in CR   100 GW

100 GW
Posts: 14319
Joined: May 20 2008 12:58am
Location: Paradise

Re: Modifying a shunt with controlled results

Post by John in CR » Jun 10 2012 7:58am

Yes Arlo and Snowy,
We should have had all the kinds of stuff you guys mention long ago...Variable regen and variable current limits on the fly. My bike requires way too much focus on throttle operation and constant use of my 3 speed switch with current limits set to deliver 30kw at 30mph, so I'm not going to be able to leave it at these settings without hurting myself at some point. I just need my 423A/550A on demand for dishing out lessons when the opportunities arise. My issue is fear of cutting traces and not being able to make new connections. Fine soldering isn't my cup of tea.

User avatar
Arlo1   100 GW

100 GW
Posts: 8375
Joined: Apr 26 2009 10:36pm
Location: Nanaimo
Contact:

Re: Modifying a shunt with controlled results

Post by Arlo1 » Jun 10 2012 11:21am

John in CR wrote:Yes Arlo and Snowy,
We should have had all the kinds of stuff you guys mention long ago...Variable regen and variable current limits on the fly. My bike requires way too much focus on throttle operation and constant use of my 3 speed switch with current limits set to deliver 30kw at 30mph, so I'm not going to be able to leave it at these settings without hurting myself at some point. I just need my 423A/550A on demand for dishing out lessons when the opportunities arise. My issue is fear of cutting traces and not being able to make new connections. Fine soldering isn't my cup of tea.
John have you tried the torque throttle in the CA yet? I set my brothers bmx up with it and its smooth off the line and smoother everywere just like lukes death bike with sevcon!
Does your project need a high performance motor drive, battery charger or other power electronics developed? Let's talk!
www.powerdesigns.ca
Leaf motor controller build. http://endless-sphere.com/forums/viewto ... 27#p963227
YSR build http://www.youtube.com/watch?v=BRo8r5g4NBg
Never above 4.2v never below 2.7v EVER!!!
Support me on Patreon. https://www.patreon.com/user/posts?u=6842045
http://www.undergroundelectrics.ca/

John in CR   100 GW

100 GW
Posts: 14319
Joined: May 20 2008 12:58am
Location: Paradise

Re: Modifying a shunt with controlled results

Post by John in CR » Jun 10 2012 1:07pm

Arlo1 wrote:John have you tried the torque throttle in the CA yet? I set my brothers bmx up with it and its smooth off the line and smoother everywere just like lukes death bike with sevcon!
No, but that sounds good. Does it work on older CA? Can anyone actually ride an e-wheelie yet, because I haven't seen one? Isn't that the real test of throttle control? I'm having to live with a 50% speed limit setting for taking off, which works ok, but a pretty big compromise.

User avatar
Arlo1   100 GW

100 GW
Posts: 8375
Joined: Apr 26 2009 10:36pm
Location: Nanaimo
Contact:

Re: Modifying a shunt with controlled results

Post by Arlo1 » Jun 10 2012 1:14pm

John in CR wrote:
Arlo1 wrote:John have you tried the torque throttle in the CA yet? I set my brothers bmx up with it and its smooth off the line and smoother everywere just like lukes death bike with sevcon!
No, but that sounds good. Does it work on older CA? Can anyone actually ride an e-wheelie yet, because I haven't seen one? Isn't that the real test of throttle control? I'm having to live with a 50% speed limit setting for taking off, which works ok, but a pretty big compromise.
I have not set my bmx up with it yet the list is to big at the moment but I know it will make controlled wheelies possible. You need a big screen CA not sure but I think all of the big screen versions work for torque throttle!
Last edited by Arlo1 on Jun 10 2012 8:31pm, edited 1 time in total.
Does your project need a high performance motor drive, battery charger or other power electronics developed? Let's talk!
www.powerdesigns.ca
Leaf motor controller build. http://endless-sphere.com/forums/viewto ... 27#p963227
YSR build http://www.youtube.com/watch?v=BRo8r5g4NBg
Never above 4.2v never below 2.7v EVER!!!
Support me on Patreon. https://www.patreon.com/user/posts?u=6842045
http://www.undergroundelectrics.ca/

John in CR   100 GW

100 GW
Posts: 14319
Joined: May 20 2008 12:58am
Location: Paradise

Re: Modifying a shunt with controlled results

Post by John in CR » Jun 10 2012 2:22pm

Cool thanks, I'll put a big screen CA on my list. In the meantime I want to put Hubmonster on some kind of recumbent, which should give me a low and forward enough CG that I can really lay on the throttle instead of easing onto it. That way I can experience the full thrust possible.

User avatar
sn0wchyld   1 MW

1 MW
Posts: 1768
Joined: Mar 18 2011 8:27pm
Location: South Aus.

Re: Modifying a shunt with controlled results

Post by sn0wchyld » Jun 11 2012 7:42pm

another thought popped up when thinking about the RV mod...

wont this affect the amp readout of plug in CA's? ie the ca still thinks its a .05ohm shunt, but really its been 'changed' to a .03ohm?

is an easy fix to wire the ca direct to the unaltered shunt? what wires are required for that?

John in CR   100 GW

100 GW
Posts: 14319
Joined: May 20 2008 12:58am
Location: Paradise

Re: Modifying a shunt with controlled results

Post by John in CR » Jun 11 2012 8:32pm

sn0wchyld wrote:another thought popped up when thinking about the RV mod...

wont this affect the amp readout of plug in CA's? ie the ca still thinks its a .05ohm shunt, but really its been 'changed' to a .03ohm?

is an easy fix to wire the ca direct to the unaltered shunt? what wires are required for that?
My CA's are already wired to the actual shunt, and won't be affected. We're fooling the controller brain, not the CA.

John

User avatar
jateureka   10 kW

10 kW
Posts: 824
Joined: Apr 06 2010 7:18pm
Location: Brisbane, QLD Australia

Re: Modifying a shunt with controlled results

Post by jateureka » Jul 04 2012 5:37am

Spacey wrote:I'd like to go the opposite way, I have one of the Mac hi torque motors with a 9 Fet controller (think it's 9 Fet). It pumps out way too much power for the long range I need, I can't program it so I was thinking of cutting one of the 2 shunts.
If you only have one shunt you could also take a Dremel tool or file and grind away part of the shunt to make it thinner, which would increase resistance and reduce current.
E-bikes: Bafang 8FUN; Mac; Ezee; FreeGo; Aprilia 7s LiPo; eLation V2; TerraTrike recumbent
E-motorbikes: ZEV 7100 LR scooter, 84V 60Ah LiFePO4.
ZERO 2011 S motorcycle, 51.8V 70Ah LiMno2, 2012 headlight, Kilovac EV-200 contactor
E-mower: EGO 56V mower & line trimmer

User avatar
made_in_the_alps_legacy   10 kW

10 kW
Posts: 702
Joined: Nov 14 2013 1:44am
Location: the alps - near italy, france, switzerland

Re: Modifying a shunt with controlled results

Post by made_in_the_alps_legacy » Jan 21 2014 4:46am

bigmoose wrote:[...] I would not be soldering shunts. I would just add a small 10 turn trimpot, perhaps 10 to 50 ohms across the shunt and then I would have an easily adjustable manipulation of the current sense.
[...][/attachment]
May I ask what is the background for the trimpot suggested resistance values ?
And for the ones who did that mod, which trimpot resistance values were used ?

User avatar
parabellum   10 MW

10 MW
Posts: 2071
Joined: Nov 19 2010 9:55am
Location: Dominican Republic, north.

Re: Modifying a shunt with controlled results

Post by parabellum » Jun 19 2014 8:38pm

Raising an old tread.
bigmoose wrote:John, I would explain it in words, but I would foul it up! Attached is another drawing with the fixed resistors labeled and an equation. Just keep the parenthesis straight and it will calculate out OK. Good luck!
currentSenseTrimpot2.jpg
sn0wchyld wrote:another thought on this RV mod, is there any harm in chaining your effective shunt R it on the fly? if not, how bout using this as a simple variable regen brake?
Where described Shunt Resistor Variable Regen Brake ever implemented by somebody? Have seen uber complicated Kingfish solution if some one wants to link it.

User avatar
Dauntless   100 GW

100 GW
Posts: 8754
Joined: May 29 2010 1:49am
Location: Coordinates: 33°52′48″N 117°55′43″W

Re: Modifying a shunt with controlled results

Post by Dauntless » Aug 08 2014 12:08am

SInce this thread is back from the dead anyway, is there a way of judging how much additional current will pass through the shunt mod? I don't feel like I've done well at all with those in the past.
Any sufficiently advanced technology is INDISTINGUISHABLE FROM MAGIC!
- Arthur C. Clarke

User avatar
made_in_the_alps_legacy   10 kW

10 kW
Posts: 702
Joined: Nov 14 2013 1:44am
Location: the alps - near italy, france, switzerland

Re: Modifying a shunt with controlled results

Post by made_in_the_alps_legacy » Aug 08 2014 12:24am

I think this is what matters...
bigmoose wrote:Ok, I see you guys soldering shunts and trimming things. Attached is a dither of some controller schematic that I snagged off the board, and how the bigMoose would trim current sense. I would not be soldering shunts. I would just add a small 10 turn trimpot, perhaps 10 to 50 ohms across the shunt and then I would have an easily adjustable manipulation of the current sense.

Just cut the trace that goes to the comparator, op amp or the micro controller. Solder in the trimpot across the shunt and dither away. If you set the wiper half way you get double the current. The rest is proportional. Just be careful to not go all the way against the wrong stop or you get "infinite" current limit!
currentSenseTrimpot.jpg

User avatar
MrDude_1   100 kW

100 kW
Posts: 1016
Joined: Aug 17 2012 3:07pm
Location: Charleston, SC

Re: Modifying a shunt with controlled results

Post by MrDude_1 » Mar 04 2015 10:06am

I know I am bumping this to the top, but has anyone done this mod on the infineon controllers?
I like the idea that I could "tune" my max current with a trimpot... but I want to make sure I do it with the correct trace.
Warning:This post is being read via light, a substance known to the state of California to cause cancer.

Zenry   1 µW

1 µW
Posts: 1
Joined: Jul 29 2015 10:56pm

Re: Modifying a shunt with controlled results

Post by Zenry » Jul 29 2015 11:17pm

Hi John and everybody.

I'm Trying to increase my motor power from 250w to at least 360W, hopefully 500W.
I just modified the shunt in the controller like suggested and it seems to have made no difference at all. Bike still runs at same slow speed (round 25km/h).
Wondering of anyone can help me with this modification, if I am doing something wrong or another alternative to boost the speed without changing battery or motor.

These are my specs: battery 36V 10Ah, Controller 36V max current 15A (I think the actual is round 7A)

User avatar
fesanand   10 W

10 W
Posts: 98
Joined: Jun 01 2014 5:48am

Re: Modifying a shunt with controlled results

Post by fesanand » Jul 29 2015 11:46pm

Zenry wrote: Bike still runs at same slow speed (round 25km/h).
Wondering of anyone can help me with this modification, if I am doing something wrong or another alternative to boost the speed without changing battery or motor.
When you mod the shunt you get better: acceleration and climb capability.
To get a better speed you need to improve the battery. Your top speed could be also restricted by the LCD display. I recommend you to open a new thread and ask how to improve the speed giving as much information about motor model, controller, bike, battery etc... we've got here great experts who will advise you :wink:

d8veh   100 GW

100 GW
Posts: 5520
Joined: Dec 10 2010 10:45am
Location: Telford

Re: Modifying a shunt with controlled results

Post by d8veh » Jul 30 2015 5:51am

That's right. Soldering he shunt improves hill-climbing ability. If you're only getting 25km/h you have an active speed restriction.

John in CR   100 GW

100 GW
Posts: 14319
Joined: May 20 2008 12:58am
Location: Paradise

Re: Modifying a shunt with controlled results

Post by John in CR » Jul 30 2015 11:17am

Zenry wrote:Hi John and everybody.

I'm Trying to increase my motor power from 250w to at least 360W, hopefully 500W.
I just modified the shunt in the controller like suggested and it seems to have made no difference at all. Bike still runs at same slow speed (round 25km/h).
Wondering of anyone can help me with this modification, if I am doing something wrong or another alternative to boost the speed without changing battery or motor.

These are my specs: battery 36V 10Ah, Controller 36V max current 15A (I think the actual is round 7A)
An increase in current increases torque, which generally won't increase speed except on hills. An increase in voltage increases rpm and in turn speed. Many of the newer systems artificially limit speed so a higher voltage may not give you higher speed. One way to tell if yours has an artificial speed limit is to check whether your max speed on flat road decreases as your battery voltage decreases. ie Is you top speed lower at the end of a ride? If speed is limited artificially then the max speed may change little, if at all.

markz   100 GW

100 GW
Posts: 9376
Joined: Jan 09 2014 11:38pm
Location: Alberta Canada

Re: Modifying a shunt with controlled results

Post by markz » Mar 28 2016 2:12pm

MrDude_1 wrote:I know I am bumping this to the top, but has anyone done this mod on the infineon controllers?
I like the idea that I could "tune" my max current with a trimpot... but I want to make sure I do it with the correct trace.
I've been pondering it myself, the soldering copper wire onto the shunt seems like an easy job however I think there might be more to the trick then just that. I have myself a 18fet I bought from Lyen people mistakenly nickname it Infineon but its actually a Xie-Chang, whats been modified by Lyen on this controller I don't really know. I keep reading over and over again that those controllers are old tech and that theres better controllers out there. But they never specify what those better controllers are. Adaptto or Sabatov or Kelly or ??????

I blew 3 of my mosfets on the yellow phase because the phase wires touched while I was trying to do the 36 combo's that John in CR mentions and dislikes. I like the shorter flow chart version process that John can do with his eyes closed. I like to work smarter not harder so I like the 6 combo's flow chart model. I've been pondering whether to send my controller to Lyen, or maybe to some other members to upgrade the controller even more. I think Zombiess does mods and another member whos name escapes me. The mosfet repair seems straight forward, if I need to match the mosfets then that is something I need to study up on. While I am doing it, I might as well solder up the shunts, and throw in some 8awg phase wire.

In the Cycle Analyst you must input the resistance of the shunt, how do you measure the shunt?

John in CR   100 GW

100 GW
Posts: 14319
Joined: May 20 2008 12:58am
Location: Paradise

Re: Modifying a shunt with controlled results

Post by John in CR » Mar 28 2016 6:10pm

I've never seen a repaired controller last very long, so I never bother anymore. YMMV.

markz   100 GW

100 GW
Posts: 9376
Joined: Jan 09 2014 11:38pm
Location: Alberta Canada

Re: Modifying a shunt with controlled results

Post by markz » Mar 29 2016 7:46pm

John in CR wrote:I've never seen a repaired controller last very long, so I never bother anymore. YMMV.
Even replacing mosfets?

jordanjozsef   100 mW

100 mW
Posts: 48
Joined: Oct 03 2018 1:00pm

Re: Modifying a shunt with controlled results

Post by jordanjozsef » May 10 2019 4:11pm

I just tried out my 3 kW high speed hub motor in a 20" rim, and it's ridiculously powerful from dead stop. I can't accelerate lightly, it immideately lifts the front wheel if I don't lean on, and it's impossible to twist the throttle when turning and going slow, because it's just way too powerful. I went way too far, when I increased the voltage to 104V (52V*2), because with the 300 w hub motor it was fine, but this 3000 W hub motor has much more torque. So the question is, how can I half the power of the controller with a switch? It has two shunts, is it possible to disable one of them with a switch while I want to slow or I want light acceleration? It's rated 108V, max. current is 42A, phase current is 100A.

User avatar
amberwolf   100 GW

100 GW
Posts: 29839
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Modifying a shunt with controlled results

Post by amberwolf » May 10 2019 11:00pm

jordanjozsef wrote:
May 10 2019 4:11pm
It has two shunts, is it possible to disable one of them with a switch while I want to slow or I want light acceleration?
Yes...but: the switch has to be able to handle at least half the current of the system. I'd recommend one that can handle a lot more, because it's resistance will be lower. That's important, because shunt resistance is very very low, and if your switch has anything anywhere near the resistance of the shunt, it would affect the reading the controller sees from it.

I don't think it has to have a high voltage rating, becuase it's in parallel with a dead short (the other shunt), so it should never arc.

What would be better is to see if the controller is programmable, and if it has a place to plug in (or wire in) a 3-speed switch. Then you set the current limit (or whatever) you want for each of those 3 settings, and switch betwheen them that way.


Alternatley, if you have a Cycle Analyst, you can use it to limit power, speed, or current, and setup presets (or an external knob) to set the limit point in operation at the moment.

jordanjozsef   100 mW

100 mW
Posts: 48
Joined: Oct 03 2018 1:00pm

Re: Modifying a shunt with controlled results

Post by jordanjozsef » May 11 2019 12:06am

It's not programmable, but it has a three speed switch. Well it's a "limited" controller, the voltage range varies from 58v to 120v. The seller said it has no regen, but I enabled it on the pcb, but it's max regen voltage is 90v, so I can't use it, I also was able to limit the max rpm, but the my half throttle was useless, because it did nothing till that. But it was still the same after that. So the only way to make the start less rough is to put a switch? Could you recommend me one on Ebay or Aliexpress? I have some switches, but they are common ones rated at 16A. But I need at least 21A, because the two shunts give me 42A total. But I will give it a try anyway, because I rarely use full throttle it's already very powerful even on quarter throttle.

User avatar
parabellum   10 MW

10 MW
Posts: 2071
Joined: Nov 19 2010 9:55am
Location: Dominican Republic, north.

Re: Modifying a shunt with controlled results

Post by parabellum » May 16 2019 9:52pm

jordanjozsef wrote:
May 11 2019 12:06am
I have some switches, but they are common ones rated at 16A. But I need at least 21A, because the two shunts give me 42A total. But I will give it a try anyway, because I rarely use full throttle it's already very powerful even on quarter throttle.
Why do you need a switch? If you remove or cut 1 shunt it will half the power and not affect speed or anything else. Try to take 1 out and see how it works, you may find bigger issue though, something called "block time", its some short time span with little to no current limiting, used to get started from a still stand in low powered setups and will make shunt removal not affect this first pull you described but just overall torque after.

jordanjozsef   100 mW

100 mW
Posts: 48
Joined: Oct 03 2018 1:00pm

Re: Modifying a shunt with controlled results

Post by jordanjozsef » May 19 2019 1:03pm

I want to have torque while I'm accelerating, but not from standstill. I had a 72V controller which had a "soft start" function, it did exactly what I want now. It was annoying with lower voltage, because it took so much time to speed up, but now it could work well. And I want to switch it, because sometimes it could come in handy, but at crowded places it's just too powerful and dangerous.

Post Reply