Broke my throttle!!

[John L]

Hi guys

I was checking out the wiring in the throttle to see if I could fit a reed switch to the brake lever. I decided against it at the moment because I didn't want to permanently wire the throttle to the brake lever.

Well I began to put it back together and in doing so I broke a lead on the transistor (I think thats what it is) right at the base - no chance of soldering it back on

I'm hoping to get a new transistor but i can't find any online that matches the number - S49E947

Anyone any ideas or should I just order a new throttle - that would be a shame as I had managed a good imitation of fleccs throttle mod.

John

PS - Came across this Pedelec, Elektrofahrrad und E-Bike - Power grip with LED 36v Gas LED 2teilig36

Looks very similar to the original except its a half throttle. The only doubt I have about is that it says its for controllers with hall sensors. However as I understand it the 8 fun motor and the controller are "no hall". Do you think this will work?

 

[flecc]

It's not a transistor, it's a Hall sensor. These look like transistors but are magnetic field sensing devices. The throttle works by passing a magnet or magnets by the sensor, the changing strength of the field varying the voltage passed by the Hall sensor to the controller.

A new throttle which is quite low cost might be the answer, either as it is or by changing over the Hall sensor.

P.S. Just seen the following two posts. Whether a motor is a sensorless one or not doesn't affect the throttle being a Hall one. The throttle is a completely different circuit and yours is a Hall one.
.

 

[John L]

It's not a transistor, it's a Hall sensor. These look like transistors but are magnetic field sensing devices. The throttle works by passing a magnet or magnets by the sensor, the changing strength of the field varying the voltage passed by the Hall sensor to the controller.

A new throttle which is quite low cost might be the answer, either as it is or by changing over the Hall sensor.

P.S. Just seen the following two posts. Whether a motor is a sensorless one or not doesn't affect the throttle being a Hall one. The throttle is a completely different circuit and yours is a Hall one.
.

Many thanks Flecc - no wonder I couldn't find a transistor with that number! Seems like that throttle will be fine - just needed some reassurance

Hope you don't mind me following up with another question. As I'm ordering the throttle I might as well order a pedelec sensor as well. The original that came with the sunlova kit doesn't fit on either side of the bottom bracket.

These take up much less room but again I'm not sure if they are suitable for my set up. Pedelec, Elektrofahrrad und E-Bike - Pedelec WL Pd
Pedelec, Elektrofahrrad und E-Bike - Pedelec Pd Kb1+Geber

Do you think these will be ok with my set-up?

John

 

[flecc]

That I can't really say John, they could be. You need one with the same evenly spaced number of magnets inserted and the same magnet polarity, though if reversible, the polarity can be corrected if necessary of course.

P.S. Although most Hall throttles are similar and that one may be ok, it's safest to get the correct one since the voltage and characteristics etc can vary.

This web link to RS components search shows the large range of Hall effect sensors around and their range of characteristics.

This Hall sensor looks suitable if the size is about right since most on our bikes use 5 volts, but I can't absolutely guarantee that of course. Temporarily out of stock, but a search in the RS site will probably find a close alternative in the 73 listed
.

 

[John L]

That I can't really say John, they could be. You need one with the same evenly spaced number of magnets inserted and the same magnet polarity, though if reversible, the polarity can be corrected if necessary of course.

P.S. Although most Hall throttles are similar and that one may be ok, it's safest to get the correct one since the voltage and characteristics etc can vary.

This web link to RS components search shows the large range of Hall effect sensors around and their range of characteristics.

This Hall sensor looks suitable if the size is about right since most on our bikes use 5 volts, but I can't absolutely guarantee that of course. Temporarily out of stock, but a search in the RS site will probably find a close alternative in the 73 listed
.

Hi Flecc - thats brilliant - thanks for going to the trouble I'll have a close look at the hall sensors. In relation to the pedelec sensor the original doesn't have this magnet set up - I'll take it apart and take a few photos and maybe ask a few more questions in another thread. Cheers.

John

 

[John L]

I contacted sunlova and they can provide me with a replacement throttle for £16 including postage which is pretty good.

I had a look at the RS site and all the likely sensors are currently out of stock.

I did find this China Hall Effect Sensor. Nanjing Manufacturer, Exporter - I'm making a big leap by presuming that 49E is the same basic reference to the S49E 947 on my sensor. I don't know anything about the company or whether they supply direct to customers.

Anyway its probably easiest to buy the throttle from sunlova.

 

[flecc]

I agree John, the right throtle is safest and low enough cost.
.

 

[John L]

Fitted the new throttle and the bike is running better than before!

Once the new throttle was safely fitted I dismantled the old throttle to see what was inside. I was surprised to find a magnet and then realised how important the positioning of the sensor probably is to the throttle control. Previously when I took the cover off the old throttle to see if I could get at the wiring I carelessly tucked the sensor (thinking it was a transistor!) back wherever it would fit. I guess it wasn't as close to the magnet as it should have been. The new throttle is running the motor a bit quicker maybe 1 - 2 mph quicker. I'm putting this down to the untampered with throttle!

I won't be messing with the throttle again!

John

 

[flecc]

Yes, they do have to be close to sense the changing magnetic field strength accurately John.

In fact they come in two varieties, one with a single long curved bar magnet, the other type having a small magnet at each end of the rotation arc. I don't either is better, they are all a bit sharp acting, magnetic fields being very non-linear.
.

 

[John L]

The one in my throttle is a long curved magnet. You learn something new everyday!

 

[Troy]

Hi,I've just joined and cant seem to post elsewhere so can I ask here for some help as the thread looks similar!

I'm looking for a replacement twist grip hand throttle for my Mums Electric Trike Wheelchair, it was made by a now 'out of business' company called PDQ.
I have been advised that its a "magnetically operated proximity centre throttle", I did purchase a throttle for an electric scooter but it had no control over the speed and I've been told it's because it's a 'variable' throttle.
Heres a link to a picture I uploaded of the old throttle that shows a broken wire that was attached to what I assume is a hall sensor, it looks too fiddly to repair.

PDQ Powertrike throttle | Flickr - Photo Sharing!

I would just like to replace the whole throttle with a new one but the Mobility company that bought all the old stock from wanted £70 incl postage to replace which seems a bit expensive for a hand throttle!

The front wheel of the trike has a 150watt motor powered by a 36volt battery

Really hope someone can help
Thanks
Troy

 

[Scimitar]

There's no shortage of throttle assemblies on ebay and elsewhere...
http://www.conhismotor.com/ProductsList.asp?iPage=3&id=122
However, I don't know for sure what would be a straight replacement for yours.

 

[flecc]

Yours look like a perfectly normal Hall sensor throttle so I don't understand what they mean by that terminology. Obviously the connections need to be correct to control the speed, the white wire normally sending a variable 0 to 5 volts to do that, the red and black being voltage supply and ground.

Two other approaches. One is to replace the Hall sensor in your old throttle which may be possible if it has markings to identify it. The other to approach another mobility company with similar models to see if they can supply a suitable throttle. TGA Mobility have a very large range of types and also used to make an electric bike so could be suitably knowledgeable. Team Hybrid are another company who are enthusiasts in both the mobility and e-biking field and will also have suggestions.

 

[Troy]

Thank you to scimitar and flecc,
I contacted team hybrid who quoted £40 including delivery which is fine but they couldn't guarantee it would work either.
I looked on ebay before I put this post on and that's when I bought the electric scooter throttle (£9.99) but it wouldn't control the speed (I tried every combination of wiring) .That's when I contacted davinci mobility (who bought up PDQ's old stock). The technician there told me that the throttle was a "magnetically operated proximity centre throttle" and that the electric scooter throttles were different, unfortunately I just don't have enough electronics knowhow to understand what this means (if anything), but I know that the electric scooter throttle I purchased didn't work. I'm just frustrated that a Mobility company would charge so much for what I assume will be some cheaply made chinese throttle!

Anymore advice greatly appreciated

Troy

 

[flecc]

What you are being told still doesn't seem to make any sense Troy. As a throttle is rotated the influence of it's rotating magnet(s) on the Hall sensor gradually changes the output voltage from zero to it's design signal maximum, normally 5 volts. Whatever the terminology, that's the only way a Hall sensor works.

The only other thing I can think of is that the PDQ's Hall sensor is a different voltage type. Is the PDQ a 12 volt model?

 

[Troy]

Hi flecc,
It has a 36volt battery and so I assume it's a 36volt system, it has a 150 watt motor on the front wheel.

When I told the guy on the phone that the electric scooter throttle I'd purchased didn't control the speed he talked about these kind of throttles being different from the one on the PDQ and then proceeded to give me the technical explanation that I didn't really understand!
Do electric scooter throttles work differently from those found found on say an electric bike? If that's the case then maybe I just ordered the wrong thing, I cant get into the electric scooter throttle in the same way as it's sealed so I can't see if there are magnets either side of a hall sensor

Like you my I just thought it was a pretty basic design but my lack of knowledge and his blurb has me slightly confused

Troy

 

[flecc]

I'm not familiar with scooter throttles Troy, just familiar with the way Hall sensors work in throttles. As I explained, moving a magnet by one allows it to start transmitting voltage on it's signal output, the amount of voltage dependent on the closeness of the magnetic field and the magnet polarity.

To show how unfussy they are, some throttles have a single long curved bar magnet that moves by the Hall sensor, others use two small magnets, one at each end of the arc. In both cases the magnetic field polarity changes as the throttle rotates by the Hall sensor.

The only thing I can think of with mobility vehicles is that have have two legal limits, 4 mph on pavements and 8 mph on roads, so I wonder if their might be some kind of dual staging in a throttle to give drive limits.

As yours is a 36 volt system, it's very likely to use a 5 volt Hall sensor voltage. Unfortunately there are different types of Hall sensor, bipolar, latch, monolithic, omnipolar and unipolar and I don't know if yours uses one of the variants. E-bikes just use the bipolar type.

 

[Troy]

Hmmm, there is a two speed set-up but it's built into the control box, turn the key one way for slow speed and the other for fast, so the speed settings are adjusted seperately from the throttle, I'm tempted to pull open the electric scooter throttle and see whats inside.
I could also try and get the sensor from the broken throttle out and find out what variation of sensor that is.
Have you any idea what the guy on the phone meant when he said that the 'other' throttles available were 'variable' (surely they all are,including the PDQ one).
I could just buy their's but I'm sure i'm being ripped off!

 

[flecc]

I've no idea what he means Troy, they are all variable of course, and what you say about the 2 speed control rules out that as a throttle difference. Certainly those prices are a rip-off, the last one I bought was £14 and that was on the high side at the time.

 

[TwoBikes]

The other sort of throttle that used be found on some ebikes is the 5k resistive throttle, such as this:

Amazon.com: Resistive throttle 0-5K Ohm: Sports & Outdoors

Perhaps the replacement that doesn't work is one of these.