hidden wire brake sensor... ?

Looked but didn't see one here. Purchased this sensor for my back brake not the front as I feather them more. The great thing is I can now use my gear shifter brake combo now that came on my original bike. Couldn't figure out how to paste the ad on here.. Item #281294629865 on ebay. Easy to install, tie red wire into my 5v throttle and other 2 wires to the brake controller. Sorry picture file was too big, I'll have to use my other camera if I get a moment.
 
BMSBattery and other vendors sell them under HWBS or Hidden Wire Brake Sensor.


hwbs-hidden-wire-brake-sensor.jpg
 
I just got my eBike parts including two HWBS. I have the same problem as Knightly posted earlier in this thread, i.e. the brakes are always on and the red led is constantly litting.

I have one of the sensors mounted over the brake wire and it does not matter if I pull my brakes or not. The brake signals always on.

As a test I connected my other brake sensor to my controller but did not pass the brake wire through it. The brake was off and no led was litting. Later i put a wire inside this brake sensor and the brake was trigged (led was litting) and now it will never go off no matter if I remove the wire or if restart the system (disconnect -> connect the battery)

Has anyone else had these problems? How does the sensor know when the break is on or off? Does it need some calibration?

I have a S09P controller from BMSBattery with three wire brake connectors. I have checked that the correct colors are connected.
 
The sensor is directional, so make sure the brake cable comes from the brake lever feeds down through the sensor and then connects to the brake caliper. The LED on the sensor should be facing the brake caliper.

The sensor works with active low brake so your controller needs to have that, not active high.
 
http://www.ebay.com/itm/281294629865
 
It's just a switch to engage whatever form of ebrake your controller has, or to disable the motor during braking.

It does nto change anythign at all about the braking performance of your existing controller.
 
oh thanks.

then if it does not improve the braking, then there's seems to be no added value of having it...
 
They enable you to use your existing brake levers, which are probably the correct leverage for your brakes, unlike the Chinese ebrakes. They're also necessary if you have your gear changers integrated into your brake levers, so you can't use ebrakes.
 
If it is 2 wire and one is +5V then it is active high, so no, not without additional circuitry.
 
These three wire sensors work with almost any controller. If you have two-wire brake connectors, you connect the ground wire of the sensor to the ground in the brake connector and the sensor signal wire to the brake connector signal. That leaves the sensor 5v wire, which you splice into either the throttle or PAS 5v (red) wire.

If you want to be neat, there's normally a spare 5v pad on the controller's PCB next to the throttle one, so you can solder on a wire, which will give you the three wires onto which you can add the correct connector. You can buy the connectors from EBay ( JST SM 2.5 3 pin)

Note that the colours on the sensors are unusual: red is 5v as normal, but blue is signal and yellow ground.

The sensors only work in one direction. If you put them the wrong way round, they work in reverse, so on all the time and off when you apply the brake, which should be OK if your controller has only a high-level brake connector, otherwise you have to mount them the correct way round, which is normally off and on when you apply the brake.
 
I successfully just wired up my three-wire HWBS onto a controller with a two-wire brake connector.

As you can see, the red wire from the HWBS gets 'spliced' (here shoehorned) in with the red wire for the controller's throttle connector; the black wire from the controller gets connected to the yellow wire from the HWBS; and the yellow wire from the controller, goes to the blue wire on the HWBS. Very chuffed to finally get it to work.

Actually now I have no idea how to find compatible plastic/metal connectors as these don't fit but that's another challenge. If anyone knows please let me know. Thanks.

https://drive.google.com/file/d/0B7ym9WvyF_P7alBHNHJXZklLbUE/view?usp=sharing
 
Jonathon, could you do me a favor?

Before you final wire, could you test continuity on signal/ground of hwbs with brake applied and not? 5v doesn't need to be powered.

Mine tested closed no matter what I did?

+1 the jst connectors, makes me feel like a watchmater or something to succesfully do them with needle nose pliers. They must have a tool. Don't forget some heatshrink tube to sure up the fragile 22/24ga wires leaving the connector.
 
nutspecial said:
Mine tested closed no matter what I did?
Click to expand...

Yes exactly the same happened to me I think - the HWBS had its red light permanently on, and the motor wouldn't run. So (keeping with the red HWBS wire stuck in the throttle red bit like in my photo) I just swapped the other two wires around, it wasn't the intuitive setup but it worked. Then the red light would be off, motor could run, unless I pulled the brake lever, and then the red light went on and cut the motor power.

Oh - there's another thing to try. Make sure that the brake cable is pulling through and returning properly, sometimes when I've cut the cable housing it sticks, so you need to clench and unclench the brake lever a few times, give the cable a wiggle back and forth, as I gather the sensor in the HWBS can misread if things aren't pulling quite right. Apparently it can be sensitive and temperamental.

nutspecial said:
could you do me a favor?
Click to expand...

I would happily do that but I'm afraid I literally don't know what
nutspecial said:
Before you final wire, could you test continuity on signal/ground of hwbs with brake applied and not? 5v doesn't need to be powered.
Click to expand...
means, my electronics knowledge is that poor. If you can explain in very simple terms I can try it but I don't think I even know how to operate my electrical testing box thing. Sorry.
 
I appreciate the effort to help!
I'm pretty sure to have ruled out my wiring (was same as your successful combo).

Testing would tell when the sensor is opening and closing circuit. Mine tested closed no matter what I did- wire in or out, moving magnet to top or bottom of travel with wire, 5v hooked up or not.

yellow and blue tested closed, which tells me it's faulty. I would think it should only test closed(continuity) when magnet in the barrel is pulled 1/4" from resting, and possibly then only if the 5v is hooked up.
The best way I can troubleshoot is to understand the circuit's proper operation.

A cheap multimeter will test, but google or the instructions can do a much better job explaining than me. It's handy to know, but don't worry about it on account of me! I'll either try another or just scrap the idea.
 
A couple of reminders. The colours of the wires are unusual. Red is 5v, blue is signal and yellow is ground, so red to red, yellow sensor to black, and sensor blue to controller low voltage brake signal wire.

Secondly, the HWBS is directional. You have to put it on the correct end of the brake cable. One way, it's off and comes on when you operate the brake, the other way, it's on and goes off when you operate the brake. The red LED gives a clue to whether it's on off. The controller will not give power when the LED is stuck.

Occasionally, they get stuck on. This can happen if there's a problem with the brake cable. To reset it, switch off the controller, pull the brake on, switch on the controller, let go of the brake.
 
Sorry to ask a dumb question but how do you know which way is correct for mounting those sensors? I would guess that you should have the red light side facing the rider?
otherDoc
 
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