Powabyke technical help

[pedestrian]

I think this should probably be posted in technical section-but i got a message saying I didn't have permission to post there.

I'm trying to get a Powabyke Euro21 working. I've made a few mistakes, and I'm now a bit stuck. I'm hoping that if I tell you everything I've done, and all the symptoms someone may be clever enough and kind enough to help me out.

When I first got bike when I switched on ignition LED lights came on. When I pedalled and tried to use throttle I felt a brief surge of power and then nothing-the fuse was blowing. I took battery pack apart and looked for loose connection-found one where wires connected to positive and negative contacts and tightened. Put battery unit back together and into bike. Now when I switched on ignition motor I had no LED lights but motor whirred-I eventually realised I had reversed polarity by putting contact plate back wrong way round (the motor was therefore freewheeling backwards!). Fixed that and put back together. Now LED lights come on but I cannot get motor to do anything (even when pedalling).

I took out contact board and ignition barrel to check connections-all seems OK. However, there is one black connector with a red and purple wire going into it-this is not connected to anything but i can't see anywhere it could connect to (unless I have accidentally pulled connector apart and other half has disappeared back down bike tubing?). I'm guessing this is just an unused connector.

So-long post, probably bit rambling. Any help or thoughts however gratefully received.

 

[flecc]

I don't know the answer to this one, but if no answer is forthcoming, try the link to the dealers page below. Some dealers are approved service centres, these are shown on the site, and you may have one within reach of where you are. They are generally very helpful and one may put you on the right lines:

Powabyke dealer finder page
.

 

[fcurran]

I think this should probably be posted in technical section-but i got a message saying I didn't have permission to post there.

I'm trying to get a Powabyke Euro21 working. I've made a few mistakes, and I'm now a bit stuck. I'm hoping that if I tell you everything I've done, and all the symptoms someone may be clever enough and kind enough to help me out.

When I first got bike when I switched on ignition LED lights came on. When I pedalled and tried to use throttle I felt a brief surge of power and then nothing-the fuse was blowing. I took battery pack apart and looked for loose connection-found one where wires connected to positive and negative contacts and tightened. Put battery unit back together and into bike. Now when I switched on ignition motor I had no LED lights but motor whirred-I eventually realised I had reversed polarity by putting contact plate back wrong way round (the motor was therefore freewheeling backwards!). Fixed that and put back together. Now LED lights come on but I cannot get motor to do anything (even when pedalling).

I took out contact board and ignition barrel to check connections-all seems OK. However, there is one black connector with a red and purple wire going into it-this is not connected to anything but i can't see anywhere it could connect to (unless I have accidentally pulled connector apart and other half has disappeared back down bike tubing?). I'm guessing this is just an unused connector.

So-long post, probably bit rambling. Any help or thoughts however gratefully received.

Hi, can you tell me if the bike has a side stand or a chrome centre stand as these models have a built in self diagnostic check. It could be one of 4 things, assuming the battery is now ok it could be the throttle, speed sensor, circuit board or ignition. Feel free to call me tomorrow on 01225 443737 for further help. Please have the bike next to you when you call so I can talk you through a few things. Alternatively contact your local Powabyke dealer who can help you.

Regards

FrankC
Powabyke Ltd
fcurran@powabyke.com

 

[pedestrian]

Hi, can you tell me if the bike has a side stand or a chrome centre stand as these models have a built in self diagnostic check. It could be one of 4 things, assuming the battery is now ok it could be the throttle, speed sensor, circuit board or ignition. Feel free to call me tomorrow on 01225 443737 for further help. Please have the bike next to you when you call so I can talk you through a few things. Alternatively contact your local Powabyke dealer who can help you.

Regards

FrankC
Powabyke Ltd
fcurran@powabyke.com

It's got a side stand. I don't think the diagnostic thing works on this one unfortunatley, I tried it (hold throttle open and switch on ignition?) the LED lights just came on as normal. However, I don't think throttle is working (see below) so I'm wondering if that would stop the self-test working anyway?

I've put a voltmeter on the PCB (2001 version) and I think the ignition is OK-when I switch on it delvers power to positive and negative leads on the 7 pin socket. I'm not getting any power through the motion and pedal assist pins, or the throttle pin (even when spinning back wheel and opening throttle at same time). I'm thinking therefore it's a problem with throttle. Can I bypass the motion and PA sensors to confirm this?

If I'm right about throttle, I'm assuming I should check connections between throttle and PCB and then take throttle apart? Any common faults to look out for?

 

[Andy Day]

As an electronics engineer but not a Powabyke expert I'd be highly surprised if you haven't killed the speed controller, if you reversed the power supply polarity. It is possible to build protection into these units but is either costly or saps power a little.. I would reckon you won't fix it unfortunately without bits to swap, particularly if you can't get into diagnostic mode, which generally needs all the electronics to work to tell you anything useful. Of course I'm quite prepared to be disabused of these ideas by the helpful Mr Curran who is really you best bet for assistance!

 

[pedestrian]

As an electronics engineer but not a Powabyke expert I'd be highly surprised if you haven't killed the speed controller,

Andy,

Thanks for your help here. When you say "speed controller" do you mean the motion sensor (or do you mean the throttle)?

 

[Andy Day]

Well I would imagine the majority of the electronics is the PCB in the box behind the headstock of the bike, this is what I would call the speed controller, but it must also include the hall effect sensors in the motor, the sensor at the bottom bracket if you have a "pedelec" feature on your machine as I have on my 2008 Powabyke, and the twistgrip itself which may be resistive or hall effect - I don't know. The regulating elements on the PCB are almost certainly field effect transistors (FETs), and these are readily killed by many situations.

But my experience of faultfinding anything electronic is first to be sure of dc conditions - in simple terms are the battery volts going where they should be, and are they of the correct voltage, secondly is the connectivity of all the elements of the system as it should be? Remember after some years there will be the possibility of corrosion in connectors and elsewhere, and fractures of wiring - possibly unseen inside the insulating sheath. There are two ways to faultfind, one by swapping bits, 1, the dumbo approach, and 2, by measuring things and trying to understand what isn't correct. 1. is possible if you have the bits, 2. if you have the circuit diags and can read them!

But, take heart, a simple approach can often work, proving the old adage that bullshit baffles brains! Things changed after you fiddled. Could be you totalled the speed controller, maybe you disturbed a dodgy connection and now things are just different. Try to measure the continuity of all the wiring, look for signs of corrosion in connectors etc. Much of the wiring will be colour coded, so red at the twistgrip, (for example) would have continuity to the red at the other end of the twistgrip cable where it goes into the connector at the PCB. To do this you would need a simple multimeter on it's lowest resistance range, good connection = close to 000 reading, failing that you are stuck with solution 1. or 2.!

If you fiddle more and fail then things are no worse, you could always take the whole plot to a dealer although the cost may often be more related to the dealers skill than the actual fault, remember he will want to make a bob on the job and may if unscrupulous pass the cost of his inefficient diagnosis on to you, as many car repairers do!

 

[pedestrian]

Andy,

All good advice, thanks. I've used multimeter on the PCB and confirmed that power goes from battery to PCB connections when the ignition is switched on. If I "jump" power across from the + and - battery pins to the acceleration pin on the PCB the motor jumps forward.

Therefore, my thinking is that the electrics are ok from the battery to the motor. The problem is either at the accelerator or before(i.e sensors). I've checked connections from accelerator to PCB, and these seem OK. So I'm thinking problem may be in twist grip itself?

I know I must be able to bypass sensors on the PCB to see if I can isolate problem to the accelerator, but haven't worked out yet how to do it. Any thoughts?

 

[Andy Day]

Hmmm! I don't think it is as simple as that, I would imagine:-

We know the speed controller needs to see the wheel with the motor in turning before it will apply power to the motor. This is probably acheived by what we call hall effect sensors, which are semiconductors which can be turned on by close proximity to a magnet. Thus there will be one or more sensors in the hub which as the wheel rotates are turned on momentarily by a magnet, which is affixed to the hub, passing by.

This generates in simple terms a pulse which is seen by the controller which then decides the bike is moving. The next hall effect sensor which works in the same fashion as the one in the hub is the one at the bottom bracket, which senses rotation of the pedals. The third is the actual throttle. So the speed controller will need to see pulses indicating a rotating wheel + at least one pulse indicating the rotation of the pedals + an open throttle, before it will attempt to power the motor. All this is probable done with some type of micro controller - a minature and simple pre-programmed computer. It could be done with discrete components but in these days not many people would follow that design route due to complexity and cost.

So, to sum up, I think just connecting X to Y as you are indicating proves nothing, and may in fact do damage. If you have proved the integrity of all the interconnections, without detailed knowledge of electronics and circuit diagrams there is only one real solution - swapping out bits 'til you find the fault.

But bear in mind if your Powabyke is like mine it won't do anything unless you rotate the front wheel at greater than I think 3.7mph, rotate the pedals and hold the thottle open, all at the same time! Quite difficult to acheive in the shed, but it can be done!

 

[pedestrian]

Andy,

Thanks. I am a little wiser now about how the sensors work, and how I might and might not be able to test them.

I've just got new back, so I'll put this project on back burner for a while. If and when I find a solution, I'll post it in case it helps or interests anyone else.

 

[fcurran]

Hi Pedestrian,

I doubt it would be the sensors as I think on these models you have 2 sensors, one on the rear wheel (motion sensor) and one on the crack/bottom bracket axle (PAS sensor). Its very unusual for both sensors to go wrong at the same time.

Im also assuming the battery is ok as you have tested.

The eliminate the front wheel, you should be able to wire a battery directly on to the contacts on the left fork (by removing the white push in plug).

Im also assuming that as you can get lights on the LED board and have power going into the PCB, then I think the ignition will also be fine.

This leaves 2 possibilities, the twist grip throttle and the PCB (printed circuit board).

Unfortunately there are no overrides for these 2 parts, it will be a case of swapping each part and trying the bike to find the fault.

Please note on these models the bike must be moving before the motor will engage. Feel free to contact me directly for more info or contact your dealer to order the relevant parts.

Regards

FrankC
Powabyke Ltd