Hidden Wire Brake Sensor

[conv-fused]

Was just wondering if anybody has tried one of the hidden wire brake sensors?

Buy Hidden wire brake sensor, sensor, PAS sensor, Hidden Wire Brake Sensor /HWBS at Aliexpress.com

 

[TwoBikes]

I have bought two for a future project, buy I don't know how they work. I've asked for a circuit diagram but they haven't responded. There are three connections. The center one appears to be a common. A meter across the center and each outer connection gives a reading of about 12 Ohms in one direction and about 5 Ohms in the other. It doesn't seem to matter whether the units are installed or uninstalled, or whether the brake is on or off, the readings never seem to change. There is a red LED somewhere in the circuit, but I've no idea what makes that come on. Looking at the casing, no pressure is applied to a switch when the brake is applied (as used to happen on devices performing the same function on old motorbikes). Instead, there seem to be a series of rollers inside the device that move when the cable moves. I just don't understand how this works.

 

[conv-fused]

I looked and wondered if it worked on the principle of an LVDT. I am not sure if they have packed in any other electronics to interface with a controller which expects a switch though.
I haven't been able to find out much about them though.

 

[JuicyBike]

Looks like a sensor rather than switch. I would imagine the brake cable moves a magnet over a sensor and this switches a transistor either on or off.
3 wires: 2 to make the switch, the third provides the power to the sensor, probably 5V.

 

[Deleted member 4366]

Looks like a sensor rather than switch. I would imagine the brake cable moves a magnet over a sensor and this switches a transistor either on or off.
3 wires: 2 to make the switch, the third provides the power to the sensor, probably 5V.

I think you've got it. My guess is a hall sensor and a magnet. Two wires are 5v and 0v, and the third is the signal. I would also guess that the signal goes high when the brakes are applied, so you need a controller with a "high" voltage brake wire like the KU63. If this is right, there must be some way of moving the magnet: either it grips on the cable somehow or it could move with pressure, but that would take up some of the cable movement before the brake operated. If there was just a switch in the device, you'd only need two wires.

Who's going to be the first to open one up?

 

[cwah]

Now available at BMSBattery:

HWBS - Hidden Wire Brake Sensor 1pcs - BMSBATTERY

Anyone tried them?

 

[Hansen]

I got one of these sensors as part of a kit bought from Kevin at Aliexpress. It seemed like an easy way to work around the problem of fitting the brake cutoffs when you have integrated brake and gearchange controls.



The kit consists of an 8fun SWXK 36V250W 205R motor in a 700C rim. Controlbox with connectors for two brake sensors (only one came with the kit) A thumb throttle, that I never got to work. (The console is the type with a 6km/h walk-your-bike button) And of course a pedelec sensor.



Installation of the brake sensor was really simple. Undo the brake wire from the front brake, slide it through the sensor, connect the electrical wire to the controlbox. Reattach the brake wire. Done!
And it works.


The controlbox is quite small



And it says on the label that the brake input is low-level.

There is a diode that lights up when I apply the brakes. The way the sensor is mounted on my bike - pointing downward - it only serves as a warning to toads and slugs in the road.

The two connectors for the brake sensors on the controlbox. Only one is in use on my bike.

The brake sensor works perfectly, but as there are three wires on this one opposed to only two on other brake handles I have installed on other bikes, I think it will only work with a controlbox prepared for this type of sensor.

But I have only a vague idea of how electricity works

 

[cwah]

That seems to be a nice kit Hansen.

How is it to deal with aliexpress? I was always wondering if we could trust these seller. Until now, ebay was my favorite place because of paypal and the review process.

Do you have nice experience with them?

It also seems that the hidden brake may be compatible with any bike?

 

[Hansen]

I had a nice experience with BTN and Kevin. They claim to ship within 3 days on their website. That does not hold true. It was more like a week. But their chat system works well and Kevin assured me that my order was being processed. My kit was held up in Customs for a little over a week (Not BTN's fault) so all in all the transaction lasted a little over 20 days.

Aliexpress has this Escrow system, so they won't release your payment to the seller until you confirm that the order has arrived in good condition. They also have a rating system, but it's nowhere as well developed as the one on Ebay.

I have bought from Aliexpress three times. A hard to find battery for a robot vacuum cleaner, a silly little lighting gadget for bicycle wheels and now this kit. All transactions have been smooth.

For the record I have also bougt kits from Sunlova/8fun UK and from a German vendor. They usually arrive within a week here in Denmark. 8fun UK charges £ 30 for freight, the German only € 9,90. The exhorbiant air-freight rates from China makes you wonder if Aliexpress is run for the benefit of the sellers or the courier companies.

I'm not sure if this brake sensor would work with with your existing controller as it has three electric wires going into the controller. Other brake sensors, mounted in the brake handles, have only two wires. I would buy a compatible controller along with the sensor.

But then, I'm a plug 'n play type.

If you consider buying the whole kit, there are one or two issues. The power cable to the motor lacks a quickly detachable connector. In case of a front wheel puncture you are f..... And I never got the thumb throttle to work. But other than that it's a nice kit with pedelec assistance coming in 6 steps all the way up to 29 km/h in high.

 

[umazooma]

i have used these on my bikes a few times - they work well but sometimes they are a little tricksy. If the red light fails to go out it can mean that the the sensor need 're-setting' (where the cable needs to 'set' the sensor in the off position before final adjustment of the brakes. Also, they sometimes 'stick' and that can be freed with a squirt of some silicon based sparay etc. (not sure about that, but a friend solved his problem in this manner). Always use positioned with the red light pointing towards the brake and not the lever. I have used mine on roller brakes very close to the brake and it works fine so it does not need to be on the handlebars, which frees one of some wires. I had another problem where a very small movement of the whole cable when moving the handlebars set off the sensor - it was so small that i could not see it move eg less than a millimetre... so these sensors are very sensitive. To my understanding, they sort of settle down after a few uses. Good idea for peace of mind to test with old piece of cable before final fitting. On a different point, i like using xlr microphone connectors as a quick release modification and sure fit for the three wire motor connector (see eBay - The UK's Online Marketplace or similar).

 

[103Alex1]

Does anyone know if this unit would work with hydraulic disc brakes ?

There seems to be a brake cable housing on the Shimano set I'm looking at which runs from the Deore XT integrated shifter right the way to the brake unit. Does the sensor work through the cable housing ?

 

[Deleted member 4366]

It only works with cable brakes. You'll have to make your own switch. You can use a hall sensor andmagnet, reed switch and magnet or mechanical micro switch. Show us a picture of your brake lever and I might be able to advise.

 

[amigafan2003]

I've just added a cut off switch to my Magura brake lever for the grand total of £2 - check out my build log http://www.pedelecs.co.uk/forum/electric-bicycles/9442-new-build-11.html#post163831

 

[103Alex1]

It only works with cable brakes. You'll have to make your own switch. You can use a hall sensor andmagnet, reed switch and magnet or mechanical micro switch. Show us a picture of your brake lever and I might be able to advise.

Here's a pics of the combined brake / gearshift levers. I have some more if needed.

 

[103Alex1]

I've just added a cut off switch to my Magura brake lever for the grand total of £2 - check out my build log http://www.pedelecs.co.uk/forum/electric-bicycles/9442-new-build-11.html#post163831

Thanks amigafan2003 ... I clocked that yesterday - was interesting to see how you went about it. I have those rim brakes on my other bike but they look different ... are there different versions of the levers ?

Pic here :