Throttle keeps frying !

jerome_speedy

100 mW
Joined
May 25, 2015
Messages
44
Location
Lyon, France
Hello all,

I have a 2WD ebike at home that gives me headaches. I installed a 2nd motor at the rear of a bike that only had one originally.
The only battery of the bike supplies the two controllers, and the brakes are only connected to the front controller.
I installed a throttle to control the extra motor, the PAS controlling the front one.

My problem is that I fried twice the hall sensor inside my throttle. At first, I thought that I pressed the brake levers while the rear motor was still running and that the controller was fried because of too much load (without cutting power). Fortunately, the controllers are both OK, it really is the throttle that didn't like something in my setup.

My throttle is this one:
throttle.jpg

Is this too low quality an item ? Should I change to a sturdier model ?
Thanks for your help
 
Check the throttle wires coming from your controller to make sure none of them show more than 5 volts with respect to each other when the controller is powered on.
 
jerome_speedy said:
My problem is that I fried twice the hall sensor inside my throttle. At first, I thought that I pressed the brake levers while the rear motor was still running and that the controller was fried because of too much load (without cutting power). Fortunately, the controllers are both OK, it really is the throttle that didn't like something in my setup.
What is the exact wiring of the throttle into the system?

If it is only connected directly to the rear controller, then what is the exact wiring of that controller into the rest of the system?

Also, if the throttle wiring runs parallel to the motor phase wires for any reason, especially if it is tightly tied down to them for a long enough completley parallel run, it might be possible for induced currents in the throttle wiring during high current motor operation to create voltages in the throttle that are higher than the sensor can handle. Not likely, but might be possible, if the conductors in the wires are close enough to each other.


Other than that, there's not much that should be able to kill the sensor itself (though I've physically broken plenty of that kind of thumb throttle, I've never had one electrically die. The closest to that is where a lead broke off the sensor from vibration.


If you want something "different" you could use a metal ATV/etc throttle body, intended to pull a cable--these come in thumb and twist versions. Then use a cable-operated hall throttle (COT) to actually run the controller. It is not as simple as just hooking it up (unlike the basic types like you have now): you'd need to adjust the cable pull so that the COT sensor output is at it's lowest (around 0.8v) when the ATV throttle is not being used. Then see if the max cable pull from the ATV throttle is enough to give you max output that you need from the controller. (sometimes it doesnt' pull the cable enough to fully turn on the COT hall sensor).

Because it's already on the trike, I use the Cycle Analyst to fix that on my SB Cruiser, taking the voltage range i get out of the COT and turning it into the range needed to fully operate my controllers, but there are mechanical ways to deal with it too.
 
After Chalo's advice, I checked the voltage from the 3 pin throttle connector: nothing ! As a matter of fact, at this time, I remembered that I only connect the 2nd motor/controller when I see fit (most of the time, the 2nd controller isn't active).
And when I powered on the 2nd controller, everything worked as expected, especially the throttle :mrgreen:

Sorry for making you "chase a red herring"

This topic can be deleted by a moderator, if they want
 
Do you mean that all of the throttles you have actually work, but that the controller they were connected to simply wasn't powered up?

If so...how did you determine that the sensors in the throttles were "fried"?

And how did you determine that the controller itself was "ok"? (the one the throttle was connected to)

I'm curious, because you implied in the first post that these tests were performed.... :?
 
OK. One of the throttle that was installed is fried. When I connect it to my bike, the rear wheel turns as soon as I power on the controller (without even touching the throttle). So I guess the sensor is now bad (this throttle is a spare in my box in my garage). The other throttle (installed on this bike) is good, as said above.
Just to make things straight: I only have 1 throttle connected on my bike (activating the rear motor), the front motor being activated with PAS. That way, I can just ask a bit more power by using the throttle.

As far as I can say, the motor with the installed throttle is OK: there is +5V on the throttle connector, and it behaves just like it should when I use the throttle. So I guess it works !

I'm sorry for the bad information I passed on in my posts above, I have several ebikes at home that I maintain, each having their peculiarities, and my brain just couldn't keep up !
 
jerome_speedy said:
One of the throttle that was installed is fried. When I connect it to my bike, the rear wheel turns as soon as I power on the controller (without even touching the throttle).
That usually means the ground wire is broken, anywhere between the throttle and the controller. ;)

I suspect that you may have an intermittent connection at the connector between controller and throttle, and it might actually be causing your problems (both this one and whatever issue you had that made you think there was a second bad throttle).

I'm sorry for the bad information I passed on in my posts above, I have several ebikes at home that I maintain, each having their peculiarities, and my brain just couldn't keep up !
That's one reason I keep a thread for each of my bikes/trikes/other-projects: I can put any problems, in detail, into each thread, and keep track of what has happened where, along with how things are presently setup, etc. Then there is a reference for "hmm...I think I've had this problem before...." and then I can go see what it was and what the fix was--and if it is really the same problem, then I know there may be a deeper issue to resolve. :)
 
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