Should I use Cycle Analyst on my build? - Wiring

General Discussion about large electric scooters and motorcycles and other things with no pedals.
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skyeg3   1 W

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Should I use Cycle Analyst on my build? - Wiring

Post by skyeg3 » Feb 03 2020 12:31am

Hello All. I am building a wheelchair/atv/off-road go cart. Motor is a perm 132 permanent magnet motor. Controller is an Alltrax SR72300. For reverse I have external reversing contactors and the throttle is a 0-5k resistive throttle. This will be running at 72V and 200 amps peak.

Currently I have no displays for voltage, amperage or anything. I am totally in the dark as far as speed and everything else. I have a Cycle Analyst mounted and was planning to use it but reading through the documentation they state "It is important that you wire up your throttle to plug into the Cycle Analyst rather than directly to your motor controller." My question is: can I not? All I want is amperage and voltage for now. My controller is not capable of regen anyway. So really my question is: Should I use the CA or just go buy something more simple? If you can recommend something please let me know. If the CA will work. Can someone explain where to wire the shunt in using the diagram below?
CA.JPG
CA.JPG (47.62 KiB) Viewed 733 times
Thank you!

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DanGT86   10 kW

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Re: Should I use Cycle Analyst on my build? - Wiring

Post by DanGT86 » Feb 03 2020 7:49am

If you dont want the CA to control the throttle or brakes that is fine. The CA is still a nice dashboard and battery monitor.

The shunt is connected to the S+ and S- wired on the CA-DP connector in your diagram. Most controllers have an internal shunt somewhere but it might be easier to use an external version. I'm not what is inside the Alltrax. I think you can get a plug and play high current shunt from ebikes.ca with the CA connector already on it.

john61ct   10 GW

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Re: Should I use Cycle Analyst on my build? - Wiring

Post by john61ct » Feb 03 2020 10:34am

If your rig is set up so that high motor temps are possible, the CA's ability to de-rate based on that is worth the price by itself.

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DanGT86   10 kW

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Re: Should I use Cycle Analyst on my build? - Wiring

Post by DanGT86 » Feb 03 2020 2:55pm

True but just to clarify, it cant de-rate or control anything without being hooked to the throttle. It can be used as a gauge only but offers lots of nice features when the throttle is connected.

john61ct   10 GW

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Re: Should I use Cycle Analyst on my build? - Wiring

Post by john61ct » Feb 03 2020 4:47pm

Yes I just mentioned that as a reason to hook the throttle up, much more valuable than display niceties

skyeg3   1 W

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Re: Should I use Cycle Analyst on my build? - Wiring

Post by skyeg3 » Feb 27 2020 2:31am

Thanks guys I agree- It would be great to hookup the throttle but the throttle is resistive 0-5k ohm. The CA wants a 0-5 volt throttle. We have a lot of time into integrating this into the hand controls. Unless someone can think of a way to inverse the voltage output on the throttle...

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Re: Should I use Cycle Analyst on my build? - Wiring

Post by amberwolf » Feb 27 2020 4:26am

skyeg3 wrote:
Feb 27 2020 2:31am
Thanks guys I agree- It would be great to hookup the throttle but the throttle is resistive 0-5k ohm. The CA wants a 0-5 volt throttle.
a 0-5k throttle hooked to the ca throttle input *is* a 0-5v throttle.

hook it up and measure the voltage (or watch it on the troubleshooting / monitoring screen of the ca). ;)

alternately, you can use a hall throttle for the ca input, because it doesn't matter what hte input is to the ca, it can deal with any voltage subrange within the 0-5v range.

so that is not the problem.

the potential problem is if your controller will only accept a resistive throttle, and cannot accept a voltage input signal (which is what the ca outputs) instead (rare). for that, you should check the manual for it.

if it doesnt' say, and if you don't have a ca yet, try it like this.

take a usb charging adapter and plug it into your wall. take an old usb cable and cut it's square end off, leaving just the end that plugs into the usb adapter. (or use a 5v charger that just ahs two wires, and cut the device-to-be-charged-end connector off). connect the ground of the 5v charger or usb cable to both one end of the throttle pot, and to the ground of the throttle input of the controller. connect the 5v of the charger or usb cable to the other end of the throtlte pot but *not* to the controller. leave the 5v of the controller's throttle port unconnected, just a loose wire. connect the center wire of the pot to the cotnroller's throttle signal input wire.

almost certainly, the controller will operate just as it would if it were powering the throttle itself. if so, then the ca can simply be set to output a 0v-5v range, instead of the 0.8-4vish range of a hall throttle. if not, then there are chips by maxim called digipots that can be built into a circuit that takes a voltage from the ca output and converts it into a resistance for the controller input. check the maxim-ic.com website for the digipot voltage-controlled-resistor appnote.

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