Chinese Connection

[flip_normal]

Sorry Knuckles I don't have a camera that can do close-ups at the moment, but all I did was solder a small piece of wire over the top of R3 to short it out. As in the green line in the pic below.


Steady hands, good eyesight (magnifying glass), decent light and a soldering iron with a small tip is all thats needed to get the job done. I kept the wire long so I could hold it in place while I soldered it and then cut the end off with side snips once I had there; much easier than trying to hold a 1/4" piece of wire with tweezers and solder it at the same time. It's important to carefully check your work with a good magnifing glass to make sure you haven't inadvertantly got solder where it shouldn't be, or melted that capacitor that's real close by.

I emailed Keywin and pointed him at this thread and Fechters instructions.

 

[Knuckles]

Great modification. I think you are the first (beyond fechter) to actually do this. Cool. Please do post on the controller performance and any ill effects of disabling the LVC by r3 shunt. Keywin does warn, however, that the LVC also protects the pcb MCU. If the voltage drops into the 20-30 V range the MCU may fry. Maybe. We just don't know.

Heck. Now I HAVE to do this mod also.

But stay tuned for Keywin' ALVC (adjustable low voltage cutoff)! Coming soon at a forum near you!

 

[lazarus2405]

If the voltage drops into the 20-30 V range the MCU may fry. Maybe. We just don't know.

This is something some people really need to know. The LVC for a 24v SLA pack is 19v, and the LVC for a 33v DeWalt pack is about 27v, and the LVC for a V28 Milwaukee pack is 25.5v. Some people actually do run them at such a low voltage, and I'd love to be able to use a low voltage pack in certain situations.

So, can we have a volunteer to test it out?

 

[Knuckles]

If the voltage drops into the 20-30 V range the MCU may fry. Maybe. We just don't know.

This is something some people really need to know. The LVC for a 24v SLA pack is 19v, and the LVC for a 33v DeWalt pack is about 27v, and the LVC for a V28 Milwaukee pack is 25.5v. Some people actually do run them at such a low voltage, and I'd love to be able to use a low voltage pack in certain situations.

So, can we have a volunteer to test it out?

Well I think you are illustrating a need for a more 'flexible' controller. Is it fair to say that it is desirable to have a controller with an operating range of 90V down to 19V?

The user can monitor Battery low V manually.
LVC thus only need protect the controller’s MCU and circuitry health.

Funny. The fabricator (Keywin) does not ride an e bike (they are banned in Shenzhen – go figure – I thought NY was bad) so he does not ‘live’ with the practical realities of bat packs, BMS, torque, speed, distance, heat, etc.

It is up to us to ASK for what we want. Keywin 'gets it' now. He'll make anything you want. ASK and Ye Shall Find!

 

[lazarus2405]

Well I think you are illustrating a need for a more 'flexible' controller. Is it fair to say that it is desirable to have a controller with an operating range of 90V down to 19V?

That'd cover over 99% if all users, I think. I can't imagine anyone running below 24v, and it doesn't make sense to build them all to operate above 90v for us few crazies.

Not to say that us crazies don't need things made! A run of 5 or 10 or so 150v controllers would be amazing.

they are banned in Shenzhen – go figure

Go figure indeed! With the traffic problems they have, you'd think...

 

[Knuckles]

I think two controller types are available:
A) Custom preset controllers (per client request)
B) On Board dip-switch adjustable controllers.

An adjustable controller would have a full range of V settings (in development).
Custom preset controllers fixed at defined settings (available now).
Modify mosfets - increase amps.
Add a CA connector too.

Make wish list.
Keywin build.

 

[Knuckles]

That'd cover over 99% if all users, I think. I can't imagine anyone running below 24v, and it doesn't make sense to build them all to operate above 90v for us few crazies.

Not to say that us crazies don't need things made! A run of 5 or 10 or so 150v controllers would be amazing.

Well right now the pcb may be pegged at 90V for the max voltage regardless of mosfet choice. Not past 90V yet.

I understand running at lower V (it’s safer). But for my motors, higher V means higher rpm. Plus I like the ZAP of my bat connectors! Keeps me on my toes!

btw my 24s-a123 pack is delivering 30 amps at 75-80V. The a123s actually warm up slightly in the metal bike forks.
My guess is 2-3 hp full throttle bursts delivered to the road. Very high performance imo.

 

[fechter]

See updates in the Shenzhen controller sticky.

The voltage regulator and LVC can be reconfigured to operate down to 19v.

I would prefer a wide input range like the Crystalyte, but jumpering a couple of big resistors is not too hard.

 

[Knuckles]

OK,

R1 and R2 control the voltage delivered to the LM78xx cascade.
Right now R1 + R2 = 470 + 470 = 960 ohm. At a battery voltage of 90V the VR cascade craps out.

To go over 90V, R1 + R2 (total resistance) must be increased. This will naturally elevate the minimum LVC required to protect the MCU.
I figure R1+R2 = Rt = 1200 ohm should allow VR operation up to about 140V.
Keywin will calculate and install the exact Rt value when he builds each controller.

This will make for a 120V nominal pack (140V full charge) but the LVC must be set at 100V to protect the MCU
(the VR cascade won’t function below bat V = 100).
4110 mosfets and 150V caps are required.

Keywin is now accepting custom orders for these controllers. Just ask Keywin to build it.
Ask for a price quote on your new custom built controller.

Payment in advance on custom orders please. I will provide all sales and customer support.

cheers

 

[Lessss]

Received my package of chargers from keywin. I swear if that package had fallen in the ocean it would have remained water tight and floated!

 

[Lock]

Hello Knuckles
Great what yer doing. Success to you.

One item that didn't get a mention in this thread (controller features to add) might be a fechter dork switch
(aka valet switch):
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=1331

Cheers
loCK

 

[Lock]

Oh yeah... and the 12v PTO was a good thought, but most here might be thinking lights only, and I am looking at much larger "house loads"... Alarm system and GPS tracking etc...
These things burn about 370W just by themselves:
http://www.ascycles.com/detail.aspx?ID=43298

tks ag'n
Loc

 

[Lessss]

How about adding a couple small fans at each end of the controller to blow air through the controller to cool it. The fan holes could be covered with a tyvek like material to let air pass through but not water.

 

[fcoreiro]

Will this controller work with a 750 Super BMC motor from powerpack motors.com I have a modified lashout bicycle and I wanted to use two 36volt20ah LiFePO4 battery packs along with your 72 volt controller. Do you think this might work?

 

[fechter]

Will this controller work with a 750 Super BMC motor from powerpack motors.com I have a modified lashout bicycle and I wanted to use two 36volt20ah LiFePO4 battery packs along with your 72 volt controller. Do you think this might work?

Nope, not yet. It would probably work at 36v, but not 72 due to the processor speed issue. See:
http://endless-sphere.com/forums/viewtopic.php?f=2&t=4282

 

[Knuckles]

For a PUMA 36V solution ...
See my post here ... http://endless-sphere.com/forums/viewtopic.php?f=2&t=5160

 

[abhimanyu]

i found a circuit in bldc motor control pcb...for overcurrent detection...im unable to figure out what exactly is happining in it...so please give your valuable suggestions...the microcontroller used is XC846..( if any one could post any document regarding the pin layout and the modules of this microcontroller that will most helpful)...below is the circuit

im using cypress microcontroller for bldc motor control in my ebike model...

everything else is sorted out except the overcurrent detection part...for which i traced the circuit which i have shown above from a pcb of some japanese ebike...it has infineon XC846..for which im unable to find any datasheet or pin config details(if u have any material related to them please post)..and i dont have the code...im trying to figureout the logic and hope to implement in my board...

any suggestions are most welcome...