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Voltage divider throttle for auto cruise: a specific design.

zacksc

⚡ Regular
Joined
Jan 26, 2019
Messages
159
Location
California, Bay Area, USA
I am planning to make a new voltage divider throttle to use for cruising on flat terrain, and I thought I would share the design here and see if anyone has any interest, comments or ideas. Essentially it uses a chain of resistors and pots, with a signal voltage coming off between the 1k resistor and the 100 Ohm pot. Here is the proposed chain:
4.8 V------1 k ohm ------signal-------100 ohm pot------100 ohm resistor------1k pot,11 detents------|

The 4.8 volts comes from the controller... The pots are both used as 2-pin variable resistors in the chain (not as 3 pin devices taking a voltage off the middle pin, which I have done in the past, but that tends to make the jumps too big.) I plan to use this with a Baserunner controller or maybe sometimes with a GR4820 (Grinfineon controller). I am thinking of trying to put this in parallel with a T-throttle; see if that works, or, if not, I could use this throttle by itself.

The 11 detent 1 k pot sets the basic throttle output level and the 100 ohm pot allows you to make small continuous adjustments to those. For example, with the 11 detent pot in its 600 ohm position you get 1.97 volts which is a reasonable modest cruise assist; you can bump that up to about 2.1 volts with the 100 ohm pot.

Not that there is anything dramatic or amazing about this design, but I think it is an improvement on just using the voltage from the middle pin of an indented pot, which gives large jumps... The overall resistance value of about 2 k or thereabouts will yield a current of about 2 or 3 milliamps, which seemed about right to me. What do you think?
 
Think about a way to quickly bring the throttle to zero in the event of an emergency. The e-brake will work but it would be nice if it doesn't try to do a wheelie when you let off the brake.
 
fechter said:
Think about a way to quickly bring the throttle to zero in the event of an emergency. The e-brake will work but it would be nice if it doesn't try to do a wheelie when you let off the brake.

I'll include a switch to either turn it off or switch in the the T lever hall throttle
 
fechter said:
Think about a way to quickly bring the throttle to zero in the event of an emergency. The e-brake will work but it would be nice if it doesn't try to do a wheelie when you let off the brake.

My CA3 thumb throttle only bikes all you have to do is hold at desired watt output for a few seconds and release, blip the throttle and it shuts it down. I have a momentary switch to activate regen and it also cuts power on the left side so I can shut down using either hand. I don't have any brake cut offs.

I guess it is kind of a pain to have to re-set the cruise function but it has become second nature at this point.
 
Certainly all in for DIY projects! But just checking if you'd seen a this product. Have seen good review.


cruisecontrol.jpg


As seen on this web site... just an example, many about.

http://electric-bikes.com/betterbikes/throttles.html



Regards,
T.C.
 
Bigwheel said:
fechter said:
Think about a way to quickly bring the throttle to zero in the event of an emergency. The e-brake will work but it would be nice if it doesn't try to do a wheelie when you let off the brake.

My CA3 thumb throttle only bikes all you have to do is hold at desired watt output for a few seconds and release, blip the throttle and it shuts it down. I have a momentary switch to activate regen and it also cuts power on the left side so I can shut down using either hand. I don't have any brake cut offs.

I guess it is kind of a pain to have to re-set the cruise function but it has become second nature at this point.

Yes, I do that too. I like it a lot. This is for a bike set up with no CA.
 
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