potentiometer wired into the signal wire of throttle

[nogas4me]

Could you wire a 0-5k pot on the throttle signal wire and set it to limit the throttle? I would like to some how be able to turn the throttle to full but limit the top speed of the bike on occasions. I figured this would be away one way to do this.

 

[deardancer3]

Here are some ideas:

If you have a straight resistive throttle, then putting a variable pot in line with the +V supply will do the trick.

or hook the new pot wiper to controller 'throtle input', one end of pot to grnd, the other end of pot to output of throttle.
tweak new pot for affect on the bike stand.

d

 

[nogas4me]

Here are some ideas:

If you have a straight resistive throttle, then putting a variable pot in line with the +V supply will do the trick.

or hook the new pot wiper to controller 'throtle input', one end of pot to grnd, the other end of pot to output of throttle.
tweak new pot for affect on the bike stand.

d

I have a hall effect throttle on the bike. It has three wires red,black and green. I assume the green wire is the throttle input to controller. Thee black wire is the ground wire. The red wire I believe is a 5v supply wire to the throttle. If this is correct then I would cut the green wire and wire one end of the green wire to the pot, The other terminal on the pot to would be wired to ground and the wiper terminal of the pot would be wired with the other end of the green wire. Does that sound right?

Also, What is a straight resistive throttle mean? If I had one I could just wire this the same way but use the red supply wire going to the throttle?

 

[deardancer3]

Here are some ideas:

If you have a straight resistive throttle, then putting a variable pot in line with the +V supply will do the trick.

or hook the new pot wiper to controller 'throtle input', one end of pot to grnd, the other end of pot to output of throttle.
tweak new pot for affect on the bike stand.

d

I have a hall effect throttle on the bike. It has three wires red,black and green. I assume the green wire is the throttle input to controller. Thee black wire is the ground wire. The red wire I believe is a 5v supply wire to the throttle. If this is correct then I would cut the green wire and wire one end of the green wire to the pot, The other terminal on the pot to would be wired to ground and the wiper terminal of the pot would be wired with the other end of the green wire. Does that sound right?

Also, What is a straight resistive throttle mean? If I had one I could just wire this the same way but use the red supply wire going to the throttle?

Yes you have it right I Believe. A hall effect throtle acts like a mini voltage generator, and if you put its output on the top of a resistor, then slide a wiper along the length of the fixed resistor, you get full output at the end close to the source, and nothing at the end close to grnd. to get partial power at max throttle, set the new pot in the midddle.

A resistive throttle is more of a voltage divider than a generator. In this case you could do the same as the first, or, just limit the current thru the throttle using a variable resistor between the original throttle and its +Voltage source.

 

[nogas4me]

Would it hinder the speed of the bike at all if the pot is turn all the way off? The reason I ask is wouldn't there be some resistance in the output line even when the pot is turned all the way off?

Also, Could I some how wire this so it is turned on by say a switch on the bike. So it would only limit the throttle when the switch is turned on? If I wired it with a switch I could just use some fixed value resistor couldn't I ?

 

[fechter]

You can add a resistor in series with the throttle line to limit it. The value of the resistance will depend on the controller. I'd guess around 50k for wiring it in series. When the resistor is all the way up, the resistance is essentially zero, so you will get full throttle. You could put a switch across the resistor to bypass it.

The other way is to add a divider to the output. This makes it pretty independent of the controller type.
Here's a diagram:

 

[nogas4me]

You can add a resistor in series with the throttle line to limit it. The value of the resistance will depend on the controller. I'd guess around 50k for wiring it in series. When the resistor is all the way up, the resistance is essentially zero, so you will get full throttle. You could put a switch across the resistor to bypass it.

The other way is to add a divider to the output. This makes it pretty independent of the controller type.
Here's a diagram:

Thank you for the pic of the circuit. So the picture you provided is an example of how I should wire the green signal wire to the top of the pot and ground to the bottom of the pot and use the wiper to send the signal to the controller. Correct?

I just looked at the way the throttle is wired now and there is a pot already wired in the throttle circuit of my XB-600. It has a small screw on the top of it does change the speed of the hub motor when turned clockwise or counter-clockwise but it doesn't slow the top speed down enough. Will it make a difference if I wire an additional pot in this circuit as we have discussed here.

50k resistor in series would just be to wire the resistor inline with the green signal wire. Is that correct as well?

What do you mean when you say put a switch across the resistor?

Could I wire a spdt switch with the com connected to the green wire from throttle and use one of the poles on the switch to connect the other end of the green wire back to the controller. Then wire the other pole with the pot circuit we have discussed here? Would that allow me to turn the varible resistance of the pot completely off if I wanted to? Also, How would the switch affect the resistance in the green throttle line when the circuit is not turned on? I would like to acheive the same top speed but be able to turn this circuit on to reduce the top speed to say half when I wanted to.
Thanks for all the help so far guys.

 

[nogas4me]

ok I think I wrote that last post wrong. Please let me know if this sounds correct. Wire the top of the pot to the signal wire from throttle and the bottom to ground. The wiper is wired to one of the poles on my spdt switch. I then wire the com of the spdt switch to the green signal wire from the controller. On the last pole of the spdt switch I wire a lead back to the green throttle wire. If this makes sense I can switch the pot completely on to adjust speed or flip the switch and turn the pot completely off and have a direct connection from throttle to the controller.

 

[nogas4me]

Does my last post sound correct? I was hoping someone would comment on this idea before I wire it to the bike . I really don't want to short anything out. Thanks

 

[deardancer3]

ok I think I wrote that last post wrong. Please let me know if this sounds correct. Wire the top of the pot to the signal wire from throttle and the bottom to ground. The wiper is wired to one of the poles on my spdt switch. I then wire the com of the spdt switch to the green signal wire from the controller. On the last pole of the spdt switch I wire a lead back to the green throttle wire. If this makes sense I can switch the pot completely on to adjust speed or flip the switch and turn the pot completely off and have a direct connection from throttle to the controller.

Wire the top of the new pot to the signal wire from old throttle wiper and the bottom of the new pot to ground. The new pot wiper is wired to one of the poles on my spdt switch. I then wire the com of the spdt switch to the green signal wire from the controller. On the last pole of the spdt switch I wire a lead back to the green original throttle wire. If this makes sense I can switch the pot completely on to adjust speed or flip the switch and turn the pot completely off and have a direct connection from throttle to the controller.

yep that looks good

 

[nogas4me]

Thank you. I did wire at as I wrote and it works great. New top speed is 18mph with circuit on and a top speed of 30mph with it off.

 

[deardancer3]

Now would you do us a favor and approach a nice constant incline hill 4-7% at 12mph, give it full throttle with no pedalling and tell us the speed in about 1/4 mile?

We are performing some data research on different ebikes. Tell us the config, the incline % and the weight.

Would be appreciated if you can, understood if you cant.

Thanks

d