Two throttles in parallel?

zacksc · Jul 9, 2020

With a Baserunner or a regular Grinfineon controller, I am planning to set something up with two throttle choices. One would be a regular linear Hall effect throttle and the other a "cruise control" voltage divider throttle which is homemade using resistors, indented pots, etc. I am thinking that I can power them both all the time with 5 volts (from the controller) and use the same return/ground wire for both and then switch the signal wire, the one that would have 1 to 3 volts on it depending on throttle position, to the one I want to use with a simple mechanical switch on my handlebars. Here are some questions I have:
1) Should I also be switching the 5 volts? Is there any reason to do that?
2) Or, at the other extreme, what would happen if I just connected both throttles in parallel. When the T-lever throttle is in the off position, would the voltage divider throttle work? How would they compete/interact with each other to determine the voltage on the signal wire going to the controller (Baserunner or ordinary Grinfineon)?
Advice much appreciated!

E-HP · Jul 9, 2020

I'm using a hall throttle and a voltage divider pot, in parallel right now because of an issue I'm having with my controller. I use a button to "activate" the voltage divider, which provides a constant throttle output to the controller, and the throttle under normal circumstances. No switching of the 5V in my setup, except to activate the pot circuit.

zacksc · Jul 9, 2020

So do you switch the signal wire from one throttle to the other?

zacksc · Jul 9, 2020

E-HP said:
I'm using a hall throttle and a voltage divider pot, in parallel right now

Thanks!
Does your throttle stay connected when you are using the voltage divider? Is the voltage divider able to overwhelm the hall throttle, or do you switch out the connection of the hall throttle to the signal wire when you use the voltage divider? Like with a single pole double throw switch?

NCC1941 · Jul 9, 2020

I'm using two hall throttles, simply wired in parallel (all 3 wires), to a Cycle Analyst 3.

The Cycle Analyst simply sees the higher of the two signal voltage inputs.

So, for example, if I set one throttle to 2.5v and the other remains at rest (around 0.85v, as is typical for hall throttles), the CA3 sees 2.5v and reacts accordingly. If, while continuing to hold the first throttle at 2.5v, I then slowly twist the second throttle, the CA3 continues to see the 2.5v of the first throttle until the second throttle exceeds 2.5v, at which point the CA3 sees the higher signal voltage of the second throttle and reacts accordingly.

E-HP · Jul 9, 2020

zacksc said:
E-HP said:

I'm using a hall throttle and a voltage divider pot, in parallel right now

Click to expand...

Thanks!
Does your throttle stay connected when you are using the voltage divider? Is the voltage divider able to overwhelm the hall throttle, or do you switch out the connection of the hall throttle to the signal wire when you use the voltage divider? Like with a single pole double throw switch?

Basically the throttle that output the most voltage takes over. So, if I used the divider (for my purpose), without throttle, it dictates the amount of throttle applied, but if I crank the throttle at the same time, the throttle dictates. No switching of anything, except for activating the pot (switch is on the +5V wire to the pot).

zacksc · Jul 9, 2020

Very cool. So neither throttle "pulls down" the other? They just send the higher voltage to the CA?

serious_sam · Jul 9, 2020

Warning, if you use 2 pots in parallel, they will short out the 5V line if one is at 100% and the other is at 0%.

amberwolf · Jul 9, 2020

Normally, paralleling hall-based throttles directly works ok. (potentiometers, not so much)

But beware that sometimes, it doesn't--either there are artifacts or the throttle may simply not function. I ran into both of these when hooking up stuff for SB Cruiser to parallel the CA's throttle output (so I could use ti for the PAS control) with the actual throttle, and being able to parallel the two throttles right and left hand, that normally independently ran each rear motor and controller.

After having tried a number of passive component type of connections, I ended up having to put diodes in series wtih each throttle signal, and living with the lower total voltage output from the throttle, and the greater "dead zone" at the bottom. It worked, but was less than desirable.

I have, however, directly paralleled a couple of regular grip throttles for a different application (just to use as position sensors), with no problems, and as noted above, the higher voltage output one "overrides" the other. I did get *some* interference, in that the voltage total output could be a few hundredths of a volt higher than if either was by itself, especially if both of them were "in use", above minimum output, but at different positions.

zacksc · Jul 11, 2020

amberwolf said:
Normally, paralleling hall-based throttles directly works ok. (potentiometers, not so much)

But beware that sometimes, it doesn't--either there are artifacts or the throttle may simply not function. I ran into both of these when hooking up stuff for SB Cruiser to parallel the CA's throttle output (so I could use ti for the PAS control) with the actual throttle, and being able to parallel the two throttles right and left hand, that normally independently ran each rear motor and controller.

After having tried a number of passive component type of connections, I ended up having to put diodes in series wtih each throttle signal, and living with the lower total voltage output from the throttle, and the greater "dead zone" at the bottom. It worked, but was less than desirable.

I have, however, directly paralleled a couple of regular grip throttles for a different application (just to use as position sensors), with no problems, and as noted above, the higher voltage output one "overrides" the other. I did get *some* interference, in that the voltage total output could be a few hundredths of a volt higher than if either was by itself, especially if both of them were "in use", above minimum output, but at different positions.

so do you think a voltage divider in parallel with a t-lever hall throttle will work? Can it damage the BaseRunner?

MadRhino · Jul 11, 2020

Sometimes it is hard to understand someone else’s requirement. This time in particular, I just can’t see the purpose.

zacksc · Jul 11, 2020

MadRhino said:
Sometimes it is hard to understand someone else’s requirement. This time in particular, I just can’t see the purpose.

Well, you can cruise at a fixed assist level with the voltage divider, without using a CA, and you can goose it with the lever throttle whenever you want. Sounds cool to me!

amberwolf · Jul 11, 2020

zacksc said:
amberwolf said:

I don't see how it could damage the BR, unless whatever yo'ure doing could exceed the voltage input the throttle connector will tolerate.

If you're worried about that, then to be certain you'd need to ask the BR's creators, Grin Tech.

Note for any readers that come later on: if unlike the OP you are using a Cycle Analyst to process the throttle inputs in any way, then you're not connecting them to the BR in the first place, so it doesn't matter--it would be the CA throttle input you'd be concerned about exceeding the voltage limits of.

Click to expand...

MadRhino · Jul 11, 2020

zacksc said:
MadRhino said:

Sometimes it is hard to understand someone else’s requirement. This time in particular, I just can’t see the purpose.

Click to expand...

Well, you can cruise at a fixed assist level with the voltage divider, without using a CA, and you can goose it with the lever throttle whenever you want. Sounds cool to me!

Maybe I am wrong but, aren’t there throttles with a cruise control for that?

zacksc · Jul 11, 2020

MadRhino said:
zacksc said:

MadRhino said:

Sometimes it is hard to understand someone else’s requirement. This time in particular, I just can’t see the purpose.

Click to expand...

Well, you can cruise at a fixed assist level with the voltage divider, without using a CA, and you can goose it with the lever throttle whenever you want. Sounds cool to me!

Click to expand...

Maybe I am wrong but, aren’t there throttles with a cruise control for that?

Well, you are not completely wrong, hahahah., but the ones that exist now have flaws such as tiny increments that are very tedious to cycle through.

MadRhino · Jul 11, 2020

I have one here that I never used, but as I understood the function, it does hold the throttle at the speed that you are going when you press the cruise button, and releases with any throttle move.

zacksc · Jul 11, 2020

That sounds pretty good. Maybe I am wrong.

Two throttles in parallel?

zacksc

100 W

E-HP

10 GW

zacksc

100 W

zacksc

100 W

NCC1941

10 W

E-HP

10 GW

zacksc

100 W

serious_sam

10 kW

amberwolf

Administrator

zacksc

100 W

MadRhino

100 GW

zacksc

100 W

amberwolf

Administrator

MadRhino

100 GW

zacksc

100 W

MadRhino

100 GW

zacksc

100 W

Similar threads