bypass broken throttle

[dnmun]

how can you tell the throttle is broken and did you open any of the other broken throttles and reglue the magnet in the right place after it broke?

 

[mcgyverism]

I hooked the throttle to a 4.5 volt dc source,then used a multimeter as per the Electric Scooter help page. No matter the position of the throttle, the voltage remains the same. I did take apart the first throttle, but the darn thing was glued together. Broke it taking it apart, and afraid to take the second one apart. I did not notice anything out of place. Everything was glued in. Again, this is attached to a wagon, it does not sustain any abusive bumps, pot holes, or anything. Just used to move the wagon on a paved road.
I would rather elliminate the throttle and just use a POT if possible.

 

[dnmun]

what was the voltage on the throttle wire if you had 4.5V on the power and the black was ground? did your controller respond if you put a small 1.2V or 3.6V source on the throttle lead?

 

[mcgyverism]

About 2.1 volts DC no matter if the throttle was engaged or not.
I did not attempt to connect any voltage directly to the controller.

this is what I did below
(Tools Needed: 4-5V DC Power Source, Multimeter) Testing a hall-effect throttle requires a 4-5 Volt DC power source (3 AA batteries will work) and a multimeter. Apply 4 through 5 Volts DC positive(+) to the throttles red wire, and apply ground(-) to the throttles black wire. Attach a multimeter between the black wire(-) and the green or blue wire(+) and engage the throttle. The output Voltage should vary between 0 through 3 Volts DC as the throttle is fully engaged. If the throttle has under 2.5 Volts DC output at full throttle that indicates that the throttle is defective.

 

[mcgyverism]

Here are two photo's of the wagon.
this shows the motor under the wagon https://www.ghilliesuits.com/mcp/controls/fileManager/download.ashx?inline=1&rootFolderID=0&relativePath=pvsoccer&fileName=wagon_motor.jpg

This is the front where the throttle WAS. I had it mounted to the handle bar. https://www.ghilliesuits.com/mcp/controls/fileManager/download.ashx?inline=1&rootFolderID=0&relativePath=pvsoccer&fileName=wagon_side.jpg

 

[mcgyverism]

Is it possible to by-pass the hall-effect throttle with a Potentiometer?
I can easily mount one in a box, to mount to the handle bars.

 

[mcgyverism]

OOPs bad link to photo's

https://www.ghilliesuits.com/pvsoccer/wagon_motor.jpg

https://www.ghilliesuits.com/pvsoccer/wagon_side.jpg

 

[bandaro]

please tell me you have that thing running when you go for a ride...

as for the pot vs hall, an rc esc uses a pot controlled servo tester so for an rc esc yes, entirely possible, but i do not know about a standard bike controller, i would assume to because the rc can be either... Ive found hall effect stuff to be much, much cheaper, so it may be best to go hall effect anyway, if they make them that is...

 

[mcgyverism]

If nobody has an answer as to replacing the Hall-effect with a potentiometer....
What is the best hall-effect throttle I can purchase that will last longer than 15 minutes of actual use.
I find it hard to believe that I've gone through two of these already, each only having been used for about 10-15 total minutes with no abuse.

 

[mcgyverism]

OK, instead of the controller and a hall-effect throttle, what about replacing everything with a good 24v DC motor controll module?

 

[amberwolf]

There's a few threads around already describing using a pot instead of hall, and the associated issues you might have with it; I'd recommend poking around for those. Some of the info is in threads not titled for throttle stuff, but there's a fair amount of info there.

Regarding other controllers, you might check out the stuff from http://4qd.co.uk ; I've used the 2QD to run CrazyBike2 when I had a powerchair motor on it. It took quite a spectacular mechanical failure to blow that controller. It runs on a pot throttle; it would take some electronics tinkering to change it to a hall type.

 

[mcgyverism]

OK, I think "dnmum" had the fix.
These throttles are made very cheap.
I took it apart and the spring almost killed me. The magnet was sitting in the center, not in the correct slot. I used lock-tight and glued the magnet back in place, then left out the spring since the cruise control function would work better for me on a wagon. I Hooked it up to a 6 volt battery pack and a multimeter. Sure enough the darn thing works like a charm all the way through the twist of the thumb knob. Apparently these magnets are not positioned, or adhered properly.

 

[auraslip]

Lots of good stuff in this thread.

My throttle recently died leaving me stranded until either bmsbattery gets me the package I've been waiting a month for already, or I get the new magura throttle from holmes hobbies that I ordered tonight.

Would it be possible to rig a momentary switch to trigger the throttle? I know the controller will ignore a full 5v, but could I use a resistor to drop it down to 4.5v?



I feel silly doing this, but honestly the cheap POS throttles now days are such a PITA to modulate that they are basically on/off switches anyways!
I really can't wait until shimano or SRAM starts releasing quality ebike components!

 

[amberwolf]

Would it be possible to rig a momentary switch to trigger the throttle? I know the controller will ignore a full 5v, but could I use a resistor to drop it down to 4.5v?

Yes, but you are going to slam power on that way. I recommend pedalling up to speed even just a little bit first if you use this method, as it will be less hard on things (and less of a surprise to you).

Oh, and the schematic you have shows 1 and 9 ohm resistors; you'll wanna use something like a thousand times that, at least.

 

[auraslip]

Yes, but you are going to slam power on that way. I recommend pedalling up to speed even just a little bit first if you use this method, as it will be less hard on things (and less of a surprise to you).

All wheelies. All the time. 8)

Oh, and the schematic you have shows 1 and 9 ohm resistors; you'll wanna use something like a thousand times that, at least.

I don't understand...I used some voltage divider calculators to get those figures...
this one http://www.raltron.com/cust/tools/voltage_divider.asp

 

[amberwolf]

Well, the problem is that 5V / 10ohms = 0.5A current flow. Need some large power resistors for that (about 2W or more, if I did math right), and maybe an upgrade to the 5V power supply in the controller to supply that much current.

The proportion of your divider is right, just that I'd recommend using 1Kohm and 9Kohm for the values, so that you have less than 1/2mA flowing instead.

 

[Alan B]

I believe the Magura is 5K, so you might use a 5K adjustable resistor (trimpot). Then you could adjust the throttle and pick the setting you like.

 

[fechter]

A typical hall throttle signal varies from 1 to 4 volts as you increase throttle (assuming 5v supply). A Magura or pot throttle will go from 0 to 5 volts. To adapt a Magura, you can add 1.2k or maybe 1k resistors in series with the 5v line and the ground line.

For a push button throttle, I remember the old BladeZ scooters had a capacitor/resistor setup that would slowly ramp up the throttle when you pushed the button. Something like this could be done, but you'd want to make sure the throttle goes back to zero as soon as you let off the button (not slowly).

 

[dnmun]

macguiver did it again, you can use a small rubber band to return the throttle to rest instead of the spring. i actually prefer the rubber band to the spring because it is less force to hold open and doesn't just snap back so quick either. good work.

 

[auraslip]

I've written an article for my website on how to repair hall throttles -

https://sites.google.com/site/shelbyelectro/electro-tech/throttle-repair

let me know what you think