Throttle Voltage Range. A warning and a Question.

[epilef]

Hi,

I just wanted to warn about the voltage range of the cheapest Hall throttle in located in Ebay Uk. Seller is Red-Circles and price doesn't arrive to 6GBP. There's nothing wrong with seller, but he doesn't specify the voltage range of the throttle. I bought the throttle and its voltage range is 0.8V to 3.12V. So I think that this info would be useful for the ebike community.

My controller specs indicate that I need a throttle range from 1.1v to 4.2v. Obviously I'm not reaching the top speed and also the 1st/3rd of the throttle is useless.


I read something about tuning the throttle response with resistances but I assume that I can't mod the throttle to get a higher voltage at WOT.

so....
does anybody know any local UK throttle to buy at that voltage range? I prefer not to buy from China, you never know if the latest explosions in Tianjin would affect the shipping process.

Thanks.

 

[Deleted member 4366]

Interesting. The voltage comes from the hall sensor inside it. It would appear that your high throttle magnet is not getting close enough. It might be worth opening it to find out why.

 

[epilef]

A new throttle is on its way. Ebay UK seller and even cheaper. 3GBP and with specs: 1 to 4v range, should be the one.

Last time I tried to open my previous throttle I broke it. They're not easy to disassemble at all. But when I receive my new throttle by thusday I can resend you d8veh this one for free if you're interested (send me a PM) as a thanks for all the knowledge you're spreading for free here and in ES.

 

[epilef]

Finally the throttle was the problem. Now I can hit the max speed.

So take into account that you might have a problem(or incompatibility) in your throttle if your bike doesn't reach the expected max speed and also you have the 1st/3rd or 1st/4er of you throttle without response.
In that case would be useful to check the output signal voltage of your throttle and compare with your controller requirements.
Cheers

 

[Deleted member 4366]

All throttles have the same type of hall sensors, so are compatible regarding the voltage. The Powabyke ones have the magnets the other way round, so they work in reverse. If your throttle was only giving 3.12v, there was something wrong with it that prevented the high throttle magnet coming to the correct position relative to the hall sensor. You should open it to find out what the problem is.

The hall sensor inside the throttle is connected to a 5v supply. Without magnets present, it gives 2.5v on the signal wire. There's two magnets inside. When the south facing one approaches the hall sensor, the voltage goes down. The minimum value is about 0.8v when the magnet touches the hall sensor. The opposite happens when you bring a north facing magnet to it. When touching, the voltage will be about 4.2v. The controller uses that voltage range to control power with a bit of a dead zone at each end, so anything below say 1v is no power and maximum power at 4v.

That's why you need brake cut-offs for a bike with a throttle. It's easy to break the plastic. That means that the low-throttle magnet won't be stopped against the hall sensor, which is the only way you can get no power. As soon as the magnet moves away from the sensor, the controller gives power. When you take both magnets away, you get half maximum power.

 

[epilef]

Thanks d8veh, as always, for the thorough info, it will help me also to repair the throttle.

No problems with the seller who immediately offered to return the item and refund.