How do I wire a D-N-R switch into a Fardriver 72680 Controller?

[shawnm]

Hi:

I'm building a vintage scooter conversion. I can find a reverse wire on the Fardriver but don't know where I should connect a "Drive" and "Neutral" wires into the controller. I didn't see anything in the documentation. I used a Kelly controller on a previous microcar build that had forward and reverse wires so it was easy. Any guidance would be appreciated. thanks

 

[E-HP]

Drive is the default, so no connection. What do you want neutral to do? Turn the scooter off? Disable your throttle?

 

[albinoe38]

From what I know about the Fardriver 72680, it doesn’t have separate “Drive” and “Neutral” wires like some other controllers do. Usually, the reverse function is handled by a dedicated reverse wire, but for forward and neutral, the controller just responds to your throttle input and brake signals.

 

[amberwolf]

Drive is the default, so no connection. What do you want neutral to do? Turn the scooter off? Disable your throttle?

If you don't want it to do anything if it's not in drive, then you could use that to power the throttle, if the d/n/r switch is built in a way that uses separate poles for each mode. If htey use a common pole, you'd have to use it to control a relay if you want it to control separate functions that don't all have a common pole themselves.

So you'll need to determine how your D/n/R switch is actually internally wired, before you can use it to control things.

 

[shawnm]

If you don't want it to do anything if it's not in drive, then you could use that to power the throttle, if the d/n/r switch is built in a way that uses separate poles for each mode. If htey use a common pole, you'd have to use it to control a relay if you want it to control separate functions that don't all have a common pole themselves.

So you'll need to determine how your D/n/R switch is actually internally wired, before you can use it to control things.

Thanks for the reply. My goal is to have the scooter in neutral when I power it up. I don't want to try to take it off the stand and inadvertently turn the throttle and have it move.

The switch has separate signal and ground wires for each module, which is good.

The throttle has three wires, a signal wire, a power wire and a ground. I can see how I could run any of the wires through the "drive" option on the switch, but once I switch out of drive to reverse I will lose the connection, so I think the reverse won't work.

Do you have any suggestions on how I could wire the throttle? thanks again

 

[shawnm]

Drive is the default, so no connection. What do you want neutral to do? Turn the scooter off? Disable your throttle?

Thanks for the reply. I want to start the bike in neutral and not have to worry about inadvertently turning the throttle and have the scooter jump when I do that.

 

[shawnm]

From what I know about the Fardriver 72680, it doesn’t have separate “Drive” and “Neutral” wires like some other controllers do. Usually, the reverse function is handled by a dedicated reverse wire, but for forward and neutral, the controller just responds to your throttle input and brake signals.

Thanks for your reply. It does have a separate reverse wire. I already have the switch mounted and it looks good so I am determined to use it

 

[chuyskywalker]

The best way to make "neutral" on the bike is likely to interrupt the throttle signal. So, if you can figure out how to wire it such that the throttle signal wire (usually green) is only live when the dial is in "D" or "R", then you could make that work.

Another option, if the N selector position completes its own, unique circuit, you could wire that into the high or low brake cutoff for the bike. Unless you are using regen, though. But that's an option to "kill" the motor power as well.

 

[E-HP]

Thanks for the reply. I want to start the bike in neutral and not have to worry about inadvertently turning the throttle and have the scooter jump when I do that.

You need ground wire, the reverse signal wire and a normally open contact for reverse. You need nothing for drive. You need a normally closed contact for neutral, inserted in the throttle signal wire.

What’s on the other side of that rotary switch?

I’m assuming you have a separate key switch to turn everything on.

 

[chuyskywalker]

If, as amberwolf mentions, this is a dial that has one input (common), with a 3 way output, then you can use two relays and some diodes to accomplish this something like this:


I don't recall if the controller reverse needs to connect to battery voltage or ground to trigger; modify as needed

(I also don't think the lower diode is needed.)

 

[amberwolf]

Thanks for the reply. My goal is to have the scooter in neutral when I power it up. I don't want to try to take it off the stand and inadvertently turn the throttle and have it move.

The switch has separate signal and ground wires for each module, which is good.

The throttle has three wires, a signal wire, a power wire and a ground. I can see how I could run any of the wires through the "drive" option on the switch, but once I switch out of drive to reverse I will lose the connection, so I think the reverse won't work.

Do you have any suggestions on how I could wire the throttle? thanks again

EDIT: chuyskywalker posted while I was thinknig and typing, the idea below:

you could use the module to drive a set of relays. The reverse and drive engage the relay that allows power to the throttle, while the reverse also engages the relay that connects your controller's reverse function. The neutral doesn't connect anything; it could even ground the throttle's power or signal wire to ensure it can't send a signal to the controller.

 

[chuyskywalker]

The neutral doesn't connect anything; it could even ground the throttle's power or signal wire to ensure it can't send a signal to the controller.

Excellent point I thought about, but did forget to mention. With *some* controllers, the throttle signal is not pulled low internally, so if you cut the signal wire, it can "float", often in the middle of the expected voltage range (0-5v), so roughly 2.5v. And if the controller reads 2.5v, that's a decent pull of the throttle and awwwayyyyyy it goes.

So if you go this route, put the motor in the air and test out what happens when you have it throttle ready, and then snip the signal wire

 

[shawnm]

The best way to make "neutral" on the bike is likely to interrupt the throttle signal. So, if you can figure out how to wire it such that the throttle signal wire (usually green) is only live when the dial is in "D" or "R", then you could make that work.

Another option, if the N selector position completes its own, unique circuit, you could wire that into the high or low brake cutoff for the bike. Unless you are using regen, though. But that's an option to "kill" the motor power as well.

I found a diagram of the switch. If I run the green wire in as the Signal input, i could connect it to the reverse wire to get reverse. I could connect the D wire to be a continuation of the throttle, which seems to be drive (by default) on the Fardriver. In Neutral nothing happens.

Does that make sense to you?

thanks

 

[chuyskywalker]

No, I think you have a misconception. The "reverse" wire on the fardriver is not an input like the throttle wire. It's an on/off flag. So you need the throttle connected and the reverse wire pulled (connected) to ground. When the reverse wire is grounded, it tells the controller to reverse the motor direction, but it's still using the throttle to know how much to move.

Follow up looking at this diagram -- is the control lit? Like with a built-in light or something? I'm curious why it needs a ground connection.

I suppose you could wire it like this:

throttle signal -> pin1
pin 2 -> controller-throttle
pin 6 -> controller-throttle

battery negative -> pin 4
pin 3 -> controller reverse

This way, in D or R the throttle is going to the controller, but when in N, it'll be cut. In addition, when in R, the reverse wire of the controller with be grounded.

That said, if the dial is lit and relying on the pin4/pin5 to make a valid 12v connection for lighting up, well....