Working to put GRIN CA3-DPS + External Shunt onto Lectric ONE

[Tom521]

As the title says I'm working to add a GRIN DPS + External Shunt onto my Lectric ONE.

Why? Because the standard Lectric speed control - tried thumb throttle first then the rotating throttle - both still act like a light switch. Can't accelerate smoothly away from a stop - just a lurch to practically wide-open throttle. Steady speed on throttle only is a joke; bike speed oscillates like a yoyo.

GRIN says that with their CA3-DPS and a Cycle Analyst molded external shunt I can have full and easy control of the throttle's behavior. It's so annoying that it's worth spending some time and money to fix it!

I have the parts in hand. I plan to put the CA3 in series with my throttle output (it's a Hall throttle BTW) and then all I need is battery voltage to the CA3 and I can try it.

I plan to retain the Lectric controller.

Presently stuck looking for battery voltage source!

I can remove and replace the Pinion drive to get battery voltage, or remove and replace the battery holder to accomplish a similar thing.

The CA3 does not need much current to operate in the throttle-only mode - only the voltage from the battery and apparently a very small current. To quote the manual: the heavy red leads are only a packaging consideration and a convenient means to pick up Vbatt+ for CA power and monitoring; they do not need to carry primary controller power.

So here's a question: is there a simpler, easier way to tap into Vbatt+ on the Lectric ONE? Maybe a used or unused plug near the handlebars?

Thank you in advance for any thoughts/ideas!

Tom

 

[RunForTheHills]

Sorry, I haven't taken apart a Lectric One. However, many/most displays have a pin going to them with battery voltage and should also have ground. You may be able to tap into that. You could test that with a multimeter.

 

[6zfshdb]

I'm not sure if Lectric uses a proprietary throttle or not, but most 3 wire Hall sensor throttles operate like this:

If you can access the throttle wiring, you may be able to insert a padding resistor in the circuit to get better throttle response. I did this successfully on my Pedego throttle.

You already have the CA3 though, so this may not be the best option.

 

[Tom521]

6zfshdb,​

Thank you! I installed the ElectricAllWheel (EAW) twist throttle to replace Lectric's thumb lever. No improvement. Interestingly it now feels exactly the same as the Lectric Trike2 750 did - no response at all for the first 10 degrees or so of twist, then hang on!

As soon as all the wiring bits arrive I will check the voltages you kindly posted - EAW told me the throttle is Hall Effect so it should work fine with the new add-in pieces from GRIN.

Probably get going next week unless the shipping delays continue.

RunForTheHills,​

Thank you again - I've ordered enough connectors to almost start a shop - when they get here I plan to follow your suggestion for a VBatt+ source by splicing into the voltage input to the present Lectric screen.

Tom

 

[RunForTheHills]

RunForTheHills,​

Thank you again - I've ordered enough connectors to almost start a shop - when they get here I plan to follow your suggestion for a VBatt+ source by splicing into the voltage input to the present Lectric screen.

Tom

I know the feeling. If you save them in a parts bin and remember you have them, it could save a future purchase.

 

[6zfshdb]

FWIW, I find a twist or thumb throttle is great for starting, especially on a hill if you forget to downshift. However, maintaining a constant speed with one of these throttles, even a properly proportioned one, can get uncomfortable after awhile. After just a few minutes, I get cramps in my thumb or wrist while trying to hold the throttle steady.

As a result, I did some experimenting and found a Hall throttle sensor can be emulated using a series of resistors. If a variable resistor (pot) is used, as in this circuit, speed can be varied, and held in position, by turning a knob. In effect, It's a form of cruise control.

Using this principle, I built a handlebar mounted "black box" speed control that can be switched on or off:

Here's a link to a thread on how it was done:

Adding a Rotary Dial Speed Control

I occasionally get a cramp in my right hand when using my half grip twist throttle. As a remedy, I built this small control box as an alternate way to adjust speed. In doing some research, I discovered a 3 wire hall effect throttle can be emulated with a variable resistor. I wired the control...

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