Hall effect throttle problem?

[thoxbui]

Hi y'all.

It started with putting in a new controller (36v, 800w, brushed controller). Everything is wired up properly, but the motor doesn't spin. the controller has only 3 wire to the throttle, and no indicator light so I can't diagnose very well.

The controller is putting out 5 volts on the throttle leads, but when I plug in the throttle, the voltage drops to 2 volts. Do I need a new throttle, or is the new controller the culprit?

Thanks.

TB

 

[johnrobholmes]

That is hard to say without further testing, but you already have some good info. Do you have a potentiometer that you could wire in and test the controller with? It would be a cheap test, and could help narrow things down between the 5v regulator and the throttle sensor.

 

[amberwolf]

I know you said everything's wired properly, but is it possible that the throttle is not actually wired correctly, and that ground and signal are reversed?

 

[thoxbui]

I know you said everything's wired properly, but is it possible that the throttle is not actually wired correctly, and that ground and signal are reversed?

Possible, not not probable... That wouldn't cause a 3 volt drop if it's just a linear hall effect chip in there...right?

 

[FMB42]

Quote:
"the controller has only 3 wire to the throttle"

How many throttle wires did the original controller have?

Some controllers will only work with a "resistive" type throttle while others will only work with a "hall effect" type throttle.

Sounds like your throttle type may not be compatible with your new controller...

 

[OlderThanDirt]

I had a similar problem when I was setting up my system early this spring. The problem was an intermittent partial short in the throttle wiring. The 5V line dropped because the controller 5V regulator was being overloaded (by about a hundred mA). If you can measure the current in the 5V line running to the throttle, it should be no more than a few mA.

To test the controller: disconnect the throttle and raise the driven wheel off the ground. Using a short piece of wire, touch the controller 5V pin to the controller throttle pin -- this will simulate a wide-open throttle and the wheel should turn rapidly. Need I say: "do NOT short the 5V pin to the ground wire?"

If you have a potentiometer handy (about 5K or so) , a more refined way is to connect the potentiometer between the controller 5V and ground pins and connect the slider to the controller throttle pin. This simulates a throttle and rotating the pot should cause the wheel to rotate smoothly.

To test the throttle: disconnect the throttle wire from the controller, leaving the 5V and ground pins connected. Measure the voltage on the throttle wire as you rotate the throttle. For a hall-effect throttle, the voltage should vary from about 0.8 volt to 4.5 volts. For a resistive throttle, it should vary from zero to 5 volts.

Hope this helps!

 

[FMB42]

Another question would be; why was the original controller replaced?

Hang in there, you'll get it going again...

 

[thoxbui]

Thanks Olderthandirt, that makes a lot of sense, and I'll try to do some more diagnostics.

Another question would be; why was the original controller replaced?
Hang in there, you'll get it going again...

Oh, I'm sure I'll get it going again. The controller is being replaced because the original one died long time ago, and I'm using the left over bits on the new project:
http://endless-sphere.com/forums/viewtopic.php?f=6&t=23467
I'm just looking for a good way of thinking through the diagnostics (w/o just swapping parts), and learn something in the process.

Thanks all.

Tho

 

[thoxbui]

Just a final follow up to my quest: the throttle is the culprit. Going through the diagnostics suggested pointed to the throttle as the problem. So a quick and inexpensive replacement throttle did the job. Thanks again, everybody.

Tho

 

[mntjohnson]

I am new to electric vehicles. The used bike I have was stuck at partial speed, so I cut halfway the 3 throttle wires to try touching them together, and now it is stuck at zero power. I have read the posts but can't be certain I understand, I really am new. Also am having trouble getting open the controller enclosure.

Is there some arrangement of the 3 wires, and a resistor, that i can use to get some speed without getting to the controller??? Thanks for any comments.

TOM JOHNSON

P.S. If it helps anyone, on ebay someone is selling 12v 15ah batteries, to replace the 12ah ones, so now a small improvement in the same space is possible -- assuming it is not fake.

 

[hardym]

so I cut halfway the 3 throttle wires to try touching them together, and now it is stuck at zero power.

My guess is that the +5 and GND wires were shorted with the power on, breaking the 5V regulator.
If you open the controller, you'll probably see a T0-220 case marked 7805. The lead closest to the "7" shoudl be at 12V compared with the center lead. The lead closest to the "5" should be at +5V compared with the center lead -- If not, replace the 7805.
Mark.

 

[mntjohnson]

Thanks for the information.

In very very basic terms, with the 3 throttle wires at hand how does one test to see if triggering them (i.e., triggering the throttle) could activate the motor.

TOM

 

[hardym]

In basic terms, there should be a wire at +5v and a wire at Gnd, and a throtle wire. Look at how they are connected at the controller, perhaps a red (+5v), black (0v) and a greeen?
To test, quickly connect the red+5 to the green throttle wire.

 

[slowlane]

harddym : FALSE ADVICE . You just put 5v into the speed sensor & probably destroyed it . A shorted throttle can / will damage the controller . There is a test procedure for brushed motors measuring the voltage outputs . DO NOT use ohm meter either .