Push Button Throttle
- Thread starter Rider90
- Start date
Jan-Erik-86
100 W
- Joined
- Jan 23, 2019
- Messages
- 110
Hi, and welcome to the forum!
What bike or controller du you have?
By push button, do you mean a simple on/off switch that switch from no power to full power, or do you want like a thumb swith where you can adjust the power? Both are usually simple to connect if your controller support a throttle, but a simple on/off switch can be dangerous, at least with a higer power ebike.
What bike or controller du you have?
By push button, do you mean a simple on/off switch that switch from no power to full power, or do you want like a thumb swith where you can adjust the power? Both are usually simple to connect if your controller support a throttle, but a simple on/off switch can be dangerous, at least with a higer power ebike.
You may need to add a resistor or two (1k) to bring the voltage to 4.2V.
https://electricbike.com/forum/forum/kits/golden-motor-magic-pie/70584-guide-to-hall-sensor-throttle-operation-testing-and-modification
(check the section on pot throttles at the bottom)
https://electricbike.com/forum/forum/kits/golden-motor-magic-pie/70584-guide-to-hall-sensor-throttle-operation-testing-and-modification
(check the section on pot throttles at the bottom)
https://endless-sphere.com/forums/viewtopic.php?f=2&t=103995&p=1520028&hilit=button#p1520028
if yo udon't want full power ewhenver you press the button, turn the pots knob until it is at the power you want it to be.
if yo udon't want full power ewhenver you press the button, turn the pots knob until it is at the power you want it to be.
Hwy89
10 kW
Trying to understand why you would want a full throttle button rather than a smooth controllable throttle which can also be used as a full throttle button. Thumb throttles are probably less expensive than the parts you would need to jury rig a button on the bars and a throttle would be a lot safer.
I tried it with a 10k potentiometer and having some issues. When I hold down the button and turn the pot knob slowly, the motor does accelerate. However when I let go of the button and press it again, it doesn’t work anymore. I have to hold the button again and readjust the knob in order for it to work.amberwolf said:
Left pin of pot to gnd
Right pin of pot to +5v
Center pin of pot to button A wire
Button B wire to controller signal wire
Rider90 said:
Did you add the two 1k resistors in series with the 5v and ground, as shown in the diagram at the bottom of the page I linked?
https://electricbike.com/forum/forum/kits/golden-motor-magic-pie/70584-guide-to-hall-sensor-throttle-operation-testing-and-modification
doesn't really matter, 10k works fine.Rider90 said:
just has to be low enough resistnace that electrical noise like rf doesn't generate voltages across it to interfere with throttle operation and high enough to minimize current draw in controller. commonly 5k-20kohm is well within this range.
that's odd.Rider90 said:
that shoudl work, as long as the pot is not set higher or lower than whatever threshold the controller has for "failed throttle".
if the contrllers throttle line is getting noise on it when not connected to the pot, then it should work to instead wire the button between right pin of pot and 5v, and directly connect controller signal wire to center pin of pot.
that will keep throttle line at zero volts except when throttle button is pushed.
i'm trying to think of another simple circuit to keep a minimum voltage on the throttle line when button isn't pressed, that doesnt' require anythign active like transistors, but atm i'm having trouble doing so.
E-HP said:
that only matters if using a pot *as* a throttle, so that it doesn't have a dead range at either end as it is twisted in use.
not relevant in this application where the pot is only used to set a single voltage that will then be applied ot throttle input.
Do i add need to add another resistor in parallel such that when the button is not pressed, there is a min voltage of 0.8v feeding to the signal line?amberwolf said:
Based on your set up when button isn’t pressed, voltage is 0 which I suspect could be causing the issue.
if the pot gets adjusted above the controllers throttle max the controller will just stop responding in the cases i've had.E-HP said:
but even if it doesnt the pot just gets adjusted down until it is running like expected, then button released and retried. if it doesn't work then adjust pot down again and repeat, until it does work.
since the pot itself, when not adjusted to either extreme, already "has resistors" between the segment in use and hte 5v and ground lines, it doesn't require external ones.
i'm pretty sure in this case his controller is detecitng the disconnect of the throttle signal and throwing an error, which the slow vs fast change in throttle voltage is then resetting.
Rider90 said:
thats a circuit that would require active electronics to deal with. a transistor circuit at the least; i tried to think of a way to just use resistors but it doesn't come out working.
the only other thing i can think of is try putting a small capacitor, like 1uf, between controller signal wire and ground, so the cap stays connected to the controller when the switch is disconnected. it's internal pulldown will drain this but not as quickly as the plain wire. if this works, the disadvantage is it takes more time for throttle to drop to zero, so it won't instantly stop providing power, and it takes more time for throtle to rise form zero to max, so it wont' instantly start providing power.
it's possible, some controllers error out if theres not enough or too much signal.
a simple-ish 2n2222 transistor circuit will do it, where there's a voltage divider on the base from 5v to ground to bias it partly on (to around 0.8v) when switch is not connected, and a pullup resistor on the collector to 5v, so that the button connects the base to the center of the pot (still wired 5v to ground on the outer pins) so that the pot voltage when connected to the base thru the switch will make the transistor collector (wired to the controller thorttle input signal) rise to the max input voltage of the controller.
sorry i don't have a schematic for that; it's just written up out of my head. if you want to try building it i'll sketch one up in paint.
This might work, but haven't checked math. Mimicking the voltage ranges of a typical hall throttle, like in Tommycat's post. 5K pot and a 20K fixed resistor, and a N/O switch.
Should output 0.88V and 4.4V when the button is pressed, I think.
Should output 0.88V and 4.4V when the button is pressed, I think.
pickworthi
100 W
Waking this thread up to say I've just built one of these following @E-HP 's diagram. I used a 5K pot, a 30K pot, two right angled connectors (2 pin and 3 pin) and a piece of solder on breadboard. Result in picture:
Calibration as follows:
- Provide a 5V DC supply across + and ground wires
- Short the 30K pot out with a jumper
- Measured from the signal wire to the ground connector, adjust the 5K pot until output on signal wire is 4.4V (or just a bit less for safety)
- Remove the "short" jumper, and adjust the 30K pot until output on signal wire is 880mV
- Done.
I hot glued little fibreglass strips to the sides and bottom to give it a bit of structural integrity, made up DuPont connectors for controller cable and momentary switch, plugged it all together and entombed the widget in insulation tape.
I attached the now fully formed "throttle switch" cable to the bike and used my "rolling road" (https://www.endless-sphere.com/forums/viewtopic.php?f=3&t=109112) to test it. Worked as expected.
I have drop handle bars, so for final attachment I positioned the momentary switch under the bars right by the right hand brake/shifter. It sits near my index finger when "on the hoods", so perfect for what I need, which is getting going on hill starts whilst struggling to get my left foot clipped into the pedal. I'm a street legal UK rider, so absolute maximum power to the hub motor is 500 ish watts - doesn't set the world alight. Also, this position keeps the switch out of view from a casual Plod inspection - should that ever happen.
The switch introduces a small risk that didn't exist before, which is that it could short out and thus cause unexpected wide open throttle. My mitigation for this are the cut out switches I have on both brakes.
Anyway - thought folk might be interested
Calibration as follows:
- Provide a 5V DC supply across + and ground wires
- Short the 30K pot out with a jumper
- Measured from the signal wire to the ground connector, adjust the 5K pot until output on signal wire is 4.4V (or just a bit less for safety)
- Remove the "short" jumper, and adjust the 30K pot until output on signal wire is 880mV
- Done.
I hot glued little fibreglass strips to the sides and bottom to give it a bit of structural integrity, made up DuPont connectors for controller cable and momentary switch, plugged it all together and entombed the widget in insulation tape.
I attached the now fully formed "throttle switch" cable to the bike and used my "rolling road" (https://www.endless-sphere.com/forums/viewtopic.php?f=3&t=109112) to test it. Worked as expected.
I have drop handle bars, so for final attachment I positioned the momentary switch under the bars right by the right hand brake/shifter. It sits near my index finger when "on the hoods", so perfect for what I need, which is getting going on hill starts whilst struggling to get my left foot clipped into the pedal.
I'm a street legal UK rider, so absolute maximum power to the hub motor is 500 ish watts - doesn't set the world alight. Also, this position keeps the switch out of view from a casual Plod inspection - should that ever happen.The switch introduces a small risk that didn't exist before, which is that it could short out and thus cause unexpected wide open throttle. My mitigation for this are the cut out switches I have on both brakes.
Anyway - thought folk might be interested
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