Rear brake regen, front cut-out only - possible?

P3yot3

100 mW
Joined
Nov 3, 2020
Messages
39
Hello all. I'm currently building a touring trike & would appreciate some input on my braking options. My current configuration is GMAC with Phaserunner L10 & CA v3.1 with the rear ebrake using proportional regen via CA while the front brakes are hydraulic disc from a single lever. I'd like to add a switch to the front brake lever that cuts the power ONLY to the motor (no regen) so that I don't need to pull the rear brake lever to cut the motor power when using the front brake only, but after scouring the webz & this forum I'm unable to find out if this is possible.

Also, as the latest CA now supports 3 wires for ebrakes I'm wondering what the purpose of the 3rd wire is for? I ask because I have the choice of both 2 & 3 wired switches/levers available so was wondering if using the 3 wire type is beneficial to my setup in some way?

Any input would be appreciated. Thanks all.
 
P3yot3 said:
Hello all. I'm currently building a touring trike & would appreciate some input on my braking options. My current configuration is GMAC with Phaserunner L10 & CA v3.1 with the rear ebrake using proportional regen via CA while the front brakes are hydraulic disc from a single lever. I'd like to add a switch to the front brake lever that cuts the power ONLY to the motor (no regen) so that I don't need to pull the rear brake lever to cut the motor power when using the front brake only, but after scouring the webz & this forum I'm unable to find out if this is possible.

Also, as the latest CA now supports 3 wires for ebrakes I'm wondering what the purpose of the 3rd wire is for? I ask because I have the choice of both 2 & 3 wired switches/levers available so was wondering if using the 3 wire type is beneficial to my setup in some way?

Any input would be appreciated. Thanks all.
You could just let of the throttle, works well with motorcycles. If you use PAS, you could stop pedaling.
 
E-HP said:
You could just let of the throttle, works well with motorcycles. If you use PAS, you could stop pedaling.

Yes, I'm aware of that, but that's not what I asked.

Thanks anyway.
 
P3yot3 said:
Hello all. I'm currently building a touring trike & would appreciate some input on my braking options. My current configuration is GMAC with Phaserunner L10 & CA v3.1 with the rear ebrake using proportional regen via CA while the front brakes are hydraulic disc from a single lever. I'd like to add a switch to the front brake lever that cuts the power ONLY to the motor (no regen) so that I don't need to pull the rear brake lever to cut the motor power when using the front brake only, but after scouring the webz & this forum I'm unable to find out if this is possible.

Also, as the latest CA now supports 3 wires for ebrakes I'm wondering what the purpose of the 3rd wire is for? I ask because I have the choice of both 2 & 3 wired switches/levers available so was wondering if using the 3 wire type is beneficial to my setup in some way?

Any input would be appreciated. Thanks all.

I think it is possible but setting cutoff source to brake 1 and regen source to brake 2 in the bacdoor app. Sadly my harness combines the inputs of brake 1 and brake 2 into a single brake line so I wasn't able to test it in action.

However you can put a cutoff mechanism for any throttle, just splice the throttle wires and put the brake + and - onto the throttle + and -. If you have throttle fault cutoff set to 5v, then it will cutoff throttle only without engaging regen, as it were a throttle fault.
 
Tommm said:
I think it is possible but setting cutoff source to brake 1 and regen source to brake 2 in the bacdoor app. Sadly my harness combines the inputs of brake 1 and brake 2 into a single brake line so I wasn't able to test it in action.

However you can put a cutoff mechanism for any throttle, just splice the throttle wires and put the brake + and - onto the throttle + and -. If you have throttle fault cutoff set to 5v, then it will cutoff throttle only without engaging regen, as it were a throttle fault.

Hi Tommm. I don't have any bluetooth connectivity so the bacdoor app isn't an option for me - or have I misunderstood what the app does?
CA also only has one ebrake input (3 wire) although it is possible to split it (daisy-chain) for both brakes, but then there's no way of choosing which brake does what in CA of course.
Your suggestion of using the throttle cut-off is definitely worth investigating though - that's exactly what I want to happen when using the front brake - I'll look into it, thanks for the suggestion. My only concern is that because I'm using the throttle for the proportional rear regen, wiring up the front ebrake to the throttle also might screw it up or cause problems. My only other option, that I could think of, was to set the proportional regen to almost zero in CA so that when I use the front brake the rear regen was minimal & I could still control the rear brake with the throttle.
I'm still clueless about weather to use two or 3 wire ebrake switches though - I'm seeing a lot of conflicting info about what the wires do exactly....

Cheers for your suggestions.
 
P3yot3 said:
Tommm said:
I think it is possible but setting cutoff source to brake 1 and regen source to brake 2 in the bacdoor app. Sadly my harness combines the inputs of brake 1 and brake 2 into a single brake line so I wasn't able to test it in action.

However you can put a cutoff mechanism for any throttle, just splice the throttle wires and put the brake + and - onto the throttle + and -. If you have throttle fault cutoff set to 5v, then it will cutoff throttle only without engaging regen, as it were a throttle fault.

Hi Tommm. I don't have any bluetooth connectivity so the bacdoor app isn't an option for me - or have I misunderstood what the app does?
CA also only has one ebrake input (3 wire) although it is possible to split it (daisy-chain) for both brakes, but then there's no way of choosing which brake does what in CA of course.
Your suggestion of using the throttle cut-off is definitely worth investigating though - that's exactly what I want to happen when using the front brake - I'll look into it, thanks for the suggestion. My only concern is that because I'm using the throttle for the proportional rear regen, wiring up the front ebrake to the throttle also might screw it up or cause problems. My only other option, that I could think of, was to set the proportional regen to almost zero in CA so that when I use the front brake the rear regen was minimal & I could still control the rear brake with the throttle.
I'm still clueless about weather to use two or 3 wire ebrake switches though - I'm seeing a lot of conflicting info about what the wires do exactly....

Cheers for your suggestions.

You want to use the brake switch to put the throttle inside fault range. Say your throttle is 0.8v to 4.5v output. You short either the black and signal to 0v to create a throttle low voltage fault or short it to 5v to create high voltage fault.
I am not sure what the range is for your throttle with that regen setup, but you have some options. An other solution would be to have an closer instead of opener brake sensor which would be wired in series and simply disconnect the signal wire of the throttle.
 
P3yot3 said:
Hello all. I'm currently building a touring trike & would appreciate some input on my braking options. My current configuration is GMAC with Phaserunner L10 & CA v3.1 with the rear ebrake using proportional regen via CA while the front brakes are hydraulic disc from a single lever. I'd like to add a switch to the front brake lever that cuts the power ONLY to the motor (no regen) so that I don't need to pull the rear brake lever to cut the motor power when using the front brake only, but after scouring the webz & this forum I'm unable to find out if this is possible.

Also, as the latest CA now supports 3 wires for ebrakes I'm wondering what the purpose of the 3rd wire is for? I ask because I have the choice of both 2 & 3 wired switches/levers available so was wondering if using the 3 wire type is beneficial to my setup in some way?

Any input would be appreciated. Thanks all.

You don't need the CA to do this. Easiest way to implement is by adding a relay switch to the battery line. Connect it to the brake level, and you'll have one brake acting as a kill switch, effectively shutting down everything. The CA will take a few seconds to reboot though every-time you brake.

The 3rd brake line on the ca allows for an effective brake signal, instead of just a switch. This way you can do ramp up braking for an instance, or use it for proportional regen. Also, some popular kits like bafang bbs mid drives use 3 line brake cables.
 
qwerkus said:
The CA will take a few seconds to reboot though every-time you brake.

I'd rather not have the CA rebooting every time I brake, plus that would render my regen braking inoperable - so that's not really an option.

qwerkus said:
The 3rd brake line on the ca allows for an effective brake signal, instead of just a switch. This way you can do ramp up braking for an instance, or use it for proportional regen.

Ah, I did wonder if that was the case - thank you for confirming - I will use the 2 wire switches then, less clutter & more simple. As time is getting on & the sun is coming out, I've decided to temporarily abandon using a switch on the front brake until a suitable & simple solution can be found & will simply add a switch to the rear disc brake lever, leaving enough play in the cable so that the disc will not fully engage until the lever is completely pulled in - leaving plenty of room to use the throttle for regen braking while the lever is partially pulled in. Might take some getting used to, but that's OK. The front hydraulic brake lever will remain the same for now. I have ordered an elcheapo hydraulic lever off the webz that has a switch built in so as soon as I find a method of wiring it to cut motor power I'll fit it.
 
P3yot3 said:
qwerkus said:
The CA will take a few seconds to reboot though every-time you brake.

I'd rather not have the CA rebooting every time I brake, plus that would render my regen braking inoperable - so that's not really an option.

Well, you can always hook the switch on the line-return wire going from the CA to the controller. This way you'd shut down the controller, while keeping the CA on. Also, that solution would allow for a smaller relay, since there is max 1amp flowing through that line. Maybe you could even wire directly the line return to the brake lever, and the brake lever to the controller, saving you the relay. Would have to be a NC (normally closed) type of brake switch.

Note that whatever config you choose, I don't think you'll be able to cut power and regen brake at the same time since either you cut power, and the controller is off - so no regen, or you activate regen and need a working controller for that, so no cut off. I was under the impression you wanted a second emergency brake in case regen is not enough.
 
qwerkus said:
I was under the impression you wanted a second emergency brake in case regen is not enough.

I probably didn't make myself clear enough - I want the motor to stop running when I use the front brake using a switch in the lever but not to turn the regen braking on - only the rear brake lever will use regen (& a disc brake for when regen is not enough).
 
P3yot3 said:
qwerkus said:
I was under the impression you wanted a second emergency brake in case regen is not enough.

I probably didn't make myself clear enough - I want the motor to stop running when I use the front brake using a switch in the lever but not to turn the regen braking on - only the rear brake lever will use regen (& a disc brake for when regen is not enough).

Maybe until you figure out a solution, you could just let off the throttle?
 
P3yot3 said:
E-HP said:
Maybe until you figure out a solution, you could just let off the throttle?

That does not compute.
You may want to consider the safety implications of what you're attempting. If you don't roll of the throttle and use the front brake lever to cut the motor, as soon as you let off the brake lever, your bike will lurch forward, since the throttle is engaged. Whether you have a switch or not, you have to let of the throttle anyway.
 
Hi,

You can do this using the hidden ebrake wire on the JST throttle connector on the Phaserunner L10.

Peel back the heatshrink covering the throttle JST connector, you should find that there are two wires going to Pin 3 of the throttle JST - a blue and a green wire.

The GREEN wire is the throttle wire and this is tied to the throttle line coming from the CA3.
The BLUE wire is the ebrake wire which triggers proportional regen.

From the factory these wires are joined together so that the CA3 can send both an incoming throttle signal at 1.1V - 3.5V and an incoming ebrake signal at 0.0V - 0.8V down the same wire and the throttle/brake voltage map separates what is a throttle signal and what is a regen signal.

If you separate these wires you can send a separate ebrake signal into the BLUE wire which will activate regen. (i.e. cut the green throttle wire off the pin and tape it up). This means you can use the front ebrake connected to the CA3 to cut the throttle, and the rear ebrake connected to the JST on the controller activate regen.

Connect your front brake to your CA3, set setting Ebk->PropRegen to disabled and set EBk->Brake Out to 0 in the CA3. This will make the CA3 cut out the throttle signal to the controller (set it to 0v) when the front brake is applied.

Option 1

Front brake = throttle cutout
Rear brake = fixed amount of regen

Connect the rear brake to the JST on the controller (after cutting off at taping up the green wire). If you have either a 3-pin (latching hall e.g. Minshine MS-BK-1R) type brake switch, or a 2-pin (sometimes described as Normally Open ("NO") or "Closer type") microswitch then connect the switch between the BLACK and BLUE wires on the JST on the controller. If you have a 2-pin brake switch, you may also need to connect a 10k Ohm pullup resistor between the Pin 1 - 5v (RED) and Pin 3 - Sig (BLUE) to prevent the signal pin from floating and giving false signals.

Use the Phaserunner suite to configure the regen. Set "Maximum Braking Effort Voltage Reading" = 0.00V and set "Max Regen Batt Current" to whatever you want your fixed regen current to be. When you pull the rear brake, the controller will activate regen at this fixed rate.

Option 2

Front brake = throttle cutout
Rear brake = proportional amount of regen controlled by throttle position

N.B. For this you will need Normally Open (NO) aka "Closer" type microswitch brake switches as above, but you cannot use hall effect brake switches like the Minshine.

Connect the front ebrake and set the settings same as Option 1.
Prepare the Phaserunner throttle JST as before by cutting and taping up the green wire.

Splice a wire into the throttle signal where it goes IN to the CA3 (CA3 throttle input JST Pin 3 - Green). Connect this new wire to Pin 1 of the rear ebrake switch. Connect Pin 2 of the rear ebrake switch to the controller JST Pin 3 - BLUE. Connect a 10k Ohm pullup resistor to the controller JST throttle connector between the Pin 1 - 5v (RED) and Pin 3 - Sig (BLUE) to prevent the signal pin from floating and giving false signals.

Use the Phaserunner suite to configure the regen. Set "Maximum Braking Effort Voltage Reading" to the same as "Throttle High Voltage Reading" and set "Brake Off Voltage Reading" to the same as "Throttle Low Voltage Reading". Set "Max Regen Batt Current" to whatever you want your maximum regen current to be. When you pull the rear brake, the controller will activate regen at a proportional amount set by the throttle handle.

The 3rd brake line on the ca allows for an effective brake signal, instead of just a switch. This way you can do ramp up braking for an instance, or use it for proportional regen.

I don't believe this is correct. There are three pins connected out of a possible four pin spaces on the CA3 brake connector. They are 1 +5V, 2 GND, 4 EBK (signal). The addition of the third pin was the addition of a +5V to enable use of latching hall effect brake sensors which require a power supply. Unless something has changed in the last 12 months to my knowledge there is no analogue brake input on the CA3 other than the fact it can use the regular throttle input combined with the ebrake input to generate a proportional regen signal to the controller.

Thanks,
Oli.
 
@ Oli.Hall :

You Sir, are a godsend - I tip my hat to you. Thank you so much for the detailed explanation for both options, it must have taken you some time to put that together - kudos to you.
Option 2 sounds exactly what I'm looking for, so I'll go with that. As soon as I saw your remark about the hidden wire on the L10 I remembered reading something about it some time ago & what it could be used for, I just couldn't remember where & how.
With regard to the 10k Ohm pullup resistor, is this the type you're referring to?

https://www.ebay.co.uk/itm/200641125344?epid=10020180715&hash=item2eb7249be0:g:pEAAAOSwhvFZDYmP

The above is rated @2W - is this sufficient, or what should be the ideal wattage rating?

Thank you so much again for your input & knowledge, it is very much appreciated.
 
Hi P3yot3,

You're welcome!

2W resistors are very large and you don't need a wattage that high. 1/4W (0.25W) is more than sufficient and are much smaller. So you can solder in-line with your wire and then cover them up with some heatshrink to protect from water etc.

Really any 10k Ohm 1/4W resistor will do, it doesn't even matter whether they are 5% or 1% tolerance. Like these:
https://www.ebay.co.uk/itm/152971924902?hash=item239dd655a6:g:lgUAAOSwLahavrG3

Good luck with the project!

thanks,
Oli.
 
Thank you @Oli.Hall for your invaluable help & info - I'll post here with an update of how I get on when I set it up.
 
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