tombenn444
1 W
So I'm waiting on my 72-volt throttle to come into the mail and I was wondering is it possible to use my high medium low speed feature on my controller and incorporate it into my throttle for a simpler three stage speed control?
Throttle bypass?
- Thread starter tombenn444
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To answer that we need to know:
What controller?
What is your "high medium low speed feature", and exactly how does it work?
What exactly do you want a "simpler three stage speed control" to do, very specifically?
What specifcally does "incorporate it into my throttle" mean?
What does your thread title "Throttle bypass?" mean in relation to your post (which does not say anything that could be equated with bypassing a throttle)?
The more details and information you can provide, the more likely it is we might be able to help. The less you tell us, and the less specific you are, the less likely we can provide useful feedback.
tombenn444
1 W
It's a Chinese no brand controller
I should say high low feature actually I'll attach pictures
Just something I can make do with instead of my throttle until it comes in the mail, really this is just theoretical I doubt I actually do it but I have a thirst of knowledge and it's been on my mind if it's possible
A temporary replacement for my throttle would be a better way to say it
I should say high low feature actually I'll attach pictures
Just something I can make do with instead of my throttle until it comes in the mail, really this is just theoretical I doubt I actually do it but I have a thirst of knowledge and it's been on my mind if it's possible
A temporary replacement for my throttle would be a better way to say it
The controller requires a voltage signal on the throttle wire, regardless of which of the three speeds are selected. For a temporary diy throttle, potentiometer and/or resistors would suffice.
Amberwolf has described how to implement these arrangements on many occasions. It's not complicated. As a learning excercise, good thing to play around with.
Just be sure the ergonomics are such that your hands are still on the grips, and hovering over the brake levers i.e. Have the pot or switches activated by thumb control, like flat bar gear shifters.
If you wanted to use a three speed switch as well, that's fine, but unnecessary, since a hall throttle or potentiometer is in effect an "infinite" speed switch.
Amberwolf has described how to implement these arrangements on many occasions. It's not complicated. As a learning excercise, good thing to play around with.
Just be sure the ergonomics are such that your hands are still on the grips, and hovering over the brake levers i.e. Have the pot or switches activated by thumb control, like flat bar gear shifters.
If you wanted to use a three speed switch as well, that's fine, but unnecessary, since a hall throttle or potentiometer is in effect an "infinite" speed switch.
I'm unclear on what you're asking, but if it's whether you can use a throttle, that also incorporates a 3-speed switch, then the answer is yes
lnanek
10 kW
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Yeah, absolute minimum is probably take the 5V throttle input, connect it to a resistor to get down to 4.2V, then connect it to the throttle signal wire.
Many controllers will ignore straight 5V on the throttle signal wire because they assume it's an electrical fault rather than the hall sensor in the throttle reading wide open throttle. So just connecting throttle signal wire to 5V wire likely wouldn't do anything.
Many controllers will ignore straight 5V on the throttle signal wire because they assume it's an electrical fault rather than the hall sensor in the throttle reading wide open throttle. So just connecting throttle signal wire to 5V wire likely wouldn't do anything.
First post; "waiting on my 72-volt throttle".
I wouldn't try to bypass that in any way to keep the controller from getting fried while correct throttle is already coming.
edit: tbh., i don't see any ebike maker being so dumb, that there would be anything like battery voltage available for the throttle.
I wouldn't try to bypass that in any way to keep the controller from getting fried while correct throttle is already coming.
edit: tbh., i don't see any ebike maker being so dumb, that there would be anything like battery voltage available for the throttle.
lnanek
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> tbh., i don't see any ebike maker being so dumb, that there would be anything like battery voltage available for the throttle.
Not just ones with voltage display, but also there's a lot of throttles that have the "ignition"/power on/power off built in as well. The wires for that are typically +[battery voltage] and a lead you connect that to for power on.
It typically only draws enough current to power the buck converter down to ~5V to power the logic circuits, though, so it doesn't require a high amperage switch like battery voltage to the circuits driving the motor would.
Not just ones with voltage display, but also there's a lot of throttles that have the "ignition"/power on/power off built in as well. The wires for that are typically +[battery voltage] and a lead you connect that to for power on.
It typically only draws enough current to power the buck converter down to ~5V to power the logic circuits, though, so it doesn't require a high amperage switch like battery voltage to the circuits driving the motor would.
Unfortunately many throttles have battery votlage running to voltmeters, switches, displays, etc built into the same module with them, along with the 5v, throttle signal, and ground, all in the same cable most of the time. So cable damage or water intrusion (both very common) can allow the battery voltage to short to the 5v and/or the throttle signal, boht of which can destroy the throttle itself *and* the controller MCU and internal PSU and anything else on the system connected to the 5v line.
But...none of the throttle sensors themselves, even potentiometer types, use battery voltage directly. (even on the increasingly rare 12v and 24v systems)
Chalo
100 TW
The kind that fails wide open when it gets wet. Grin has been avoiding those for over 20 years now. So have I.
Even assuming the throttle's battery meter will read a voltage that low, 7.2v, or 8.4v (fully charged 72v pack) or even 6v (empty 72v pack) is still high enough to blow up the typical throttle hall sensor in the event of a wiring fault, miswire, or water intrusion. Most of those are 5v max input, with perhaps half a volt tolerance above that before failure.
The MCU can't normally tolerate the above-5v either, so if it shorted to the signal line, and that goes to the MCU in the controller, it'll blow that up too, and the same of other 5v-max devices connected to any line the 8.4v shorts to.
It's safe enough to use a regular ebike voltmeter, SOC meter, etc....just don't run the cable with the battery voltage along wiht any low voltage signals or voltages, and the worst that can happen is shorting battery votlage to ground and blowing whatever fuse you used at the battery end of the wires between the meter and the battery.
Sometimes they are, sometimes they aren't. It's "always" safe to assume that the margins are that tight, but you can always check the max capability of a part with it's spec sheet, keeping in mind that clone parts or those with no spec sheet available may have even lower tolerance for overages in current or voltage.
For instance, looking up a random "5v" analog hall sensor I found the spec sheet on digikey for an A1302, similar to those you might find in a hall based throttle (not necessarily identical) is designed for "4.5 to 6.0 V operation" meaning it will operate normally within those bounds, and it's "Absolute Maximum Rating for Supply Voltage" is 8 V, above which point it would be expected to fail. So this particular part would probably survive the average wiring failure or water intrusion with the 10x reduction you'd proposed above for the voltmeter. **** I wouldn't recommend expecting all throttles (or even most of them) to do so, given the propensity for cheap clone parts to be used in many ebike bits.
Also note that "these devices have a quiescent output voltage that is 50% of the supply voltage" which means that when no magnet is present they'd be at 2.5v for a 5v supply, 3v for a 6v supply, and only 2.25v for a 4.5v supply...but the controller will probably only operate as expected when it's a 5v supply because the output as modified by the magnet presence as throttle is turned from off to full will shift along with that midpoint. (how the actual throtlte halls behave may be different as they are not usualy this part, if they are this p/n they are probably not genuine but just clones or even nonsimilar parts just marked with this number)
https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/1062/A1301,02.pdf (attached to post in case of link rot)
The ones used in motors are more tolerant; they're of a different kind that don't output any voltage, but simply ground the output when active, toggling on or off whenever a magnetic field changes polarity. But they are usually still damaged or destroyed when cable damage occurs to a hubmotor for example, because the voltages they can handle are less than the typical phase voltages present (sliced up battery voltage pulses).
This particular part that is often recommended for motor hall sensor replacement, the Honeywell SS41F, has a "wide operating voltage range of 4.5 Vdc to 24 Vdc". That lets it be powered by the diode-protected controller 5v output of only 4.5v, but just barely, and it means it can tolerate some induced voltages on the supply line (from the phase currents in the cable's parallel wires). It has an absolute maximum rating (above which it would be expected to fail) of 50v, including on the signal output line.
Again, I woudln't expect the typical halls in a motor to have that high a max rating, given the number of failures seen on them attributable to cable damage even in 36v (42v max) systems.
I didn't google any spec sheets for them, just going from memory, but most MCUs can only tolerate 3.3v or 5v, with absolute max ratings of perhaps 3.6v for the former, and 5.5v for the latter. A 3.3v MCU would probably blow up with just 5v on it, meaning it would require a buffer (opamp possibly but more probably a resistive voltage divider for cheapness) just to read a normal throttle voltage signal.
I don't know if they use them in controllers, but there are some MCUs that operate on less than 2v and would fail if anything above 1.whatever volts was applied to any pin.
****BTW, you could disconnect the decimal point LED in the typical throlttle-voltmeter display to force it to read more easily for the 10x reduction. You could also change it's input buffer gain by 10x to force it to actually read 'correctly".
I see. Thanks for that.
Black msrker pen might even do away with the decimal point.
I don't have any voltage displaying throttles to test, only one with voltage indicating LEDs. But you reckon they wouldn't function on single digit voltages anyway.
Pity, because the additional risk of using a 10:1 reduction with 10-12S Li-Ion batteries would be minimal.
Wuxing could do better by the sounds of it, if I'm understanding your last paragraph to mean that any voltage could be simply enough stepped down at the controller end then refactored at the throttle.
Black msrker pen might even do away with the decimal point.
I don't have any voltage displaying throttles to test, only one with voltage indicating LEDs. But you reckon they wouldn't function on single digit voltages anyway.
Pity, because the additional risk of using a 10:1 reduction with 10-12S Li-Ion batteries would be minimal.
Wuxing could do better by the sounds of it, if I'm understanding your last paragraph to mean that any voltage could be simply enough stepped down at the controller end then refactored at the throttle.
Doesn't hurt to try, but I would expect that these are based on simple voltmeter chips, which usually have some form of range input control or an external op-amp to scale the input, that may put the 1/10th scale input too low for it to read. But it might work just like a regular voltmeter, and display correctly.
Yes, that could easily be done. It's been suggested before on here for people that didnt' want to run battery voltage to the handlebars for anything, including even to the cycle analyst (which itself can run on as low as 12-15v, and that can be input to a separate wire than what is measuring battery voltage for readouts).
"Suggested", as in unrealised designs?
Be nice to have one less thing on the handlebars, and one less independent cable to them.
It does make sense - if you don't need display and mode switching, only volt data - to incorporate a little display in the throttle.
Be nice to have one less thing on the handlebars, and one less independent cable to them.
It does make sense - if you don't need display and mode switching, only volt data - to incorporate a little display in the throttle.
Chalo
100 TW
It makes more sense to put a separate voltmeter on the handlebars that can't leak voltage to the throttle signal wire.
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