Hydraulic brake sensor

General Discussion about large electric scooters and motorcycles and other things with no pedals.
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TilmanBaumann   10 W

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Hydraulic brake sensor

Post by TilmanBaumann » Jul 05 2018 7:26am

Is there some plug and play solution to get some analogue braking response for dynamic regen braking?
I suspect one could just pick up the pressure in the brake lines via a pressure transducer.

I have not ridden a bike with strong regen, it's still in bits on my living room floor. 8)
That electric scooter came from the factory without regen braking. I'm changing the powertrain right now. :lol:
I just assume it wouldn't feel very nice if I just hooked on/off-braking tot he brake light sensor. Could feel a bit odd if it slammed in regen braking as soon as you touched the brakes.
But I basically lack the driving experience. Perhaps that is just a solid option together with regen when going off the throttle.

What do you guys think? Should I even bother? Rely on throttle braking entirely?
And where can I buy one? [EU]
The other consideration is, a pressure transducer would only pick up braking action once the brake pads clamp. A magnetic HAL sensor on the brake leaver would pick up braking action before the brakes actually grip.

Do proper motorbike quality hydraulic brake handles exist with HAL sensors? I have only seen some dodgy retrofit ones or some for bicycles.

Cheers and thanks

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fechter   100 GW

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Re: Hydraulic brake sensor

Post by fechter » Jul 05 2018 8:35am

I'm not aware of any affordable hydraulic pressure sensors. Having something on the brake lever is better as you want the regen to engage before the brake pads touch. Again, not much is available off the shelf. I have seen linear potentiometers with short travel plungers that are waterproof you could make a DIY version.

I have regen on one bike and it is a fixed level. As long as you get the level set right, it works pretty well. It won't stop the bike, but it really reduces the wear on the brake pads. The amount of energy you can recover from regen is not really significant in most cases. In very hilly areas I might get as much as 10% back but most of the time it is much less than that.
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flippy   10 kW

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Re: Hydraulic brake sensor

Post by flippy » Jul 15 2018 11:07am

you can get sensors that go on the lever, you dont want to activate on pressure because you want the regen to work BEFORE the brake does.

or you can get a trottle that has regen built in. but those are quite expensive from what i read.

or do this:

http://www.avdweb.nl/solar-bike/mechani ... witch.html

cheap and only requires some messing with the ssettings in the controller.
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ElectricGod   10 MW

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Re: Hydraulic brake sensor

Post by ElectricGod » Jul 30 2018 6:19pm

I bought some of these. They replace the banjo bolt. It's just an on/off switch that's pressure activated.

https://www.ebay.com/itm/Motorcycle-Bik ... 2749.l2649

If you are looking for something that actually measures pressure, then any hydraulic pressure guage will tell you that or a pressure sending unit like this. There's probably a piezo in there that flexes with increased pressure and presents a voltage. OR since it's for 5 volts...maybe some kind of small pressure sensitive resistor?

https://www.ebay.com/itm/5V-G1-4-0-1-2- ... =R40&rt=nc
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flippy   10 kW

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Re: Hydraulic brake sensor

Post by flippy » Jul 30 2018 11:46pm

why mess with the hydraulic lines? they give out the wrong signal band and if they did it's still the wrong way. you need the regen to activate before the brake disks do.
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TilmanBaumann   10 W

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Re: Hydraulic brake sensor

Post by TilmanBaumann » Aug 02 2018 5:21am

You are right. I will try to get some kind of analogue response by using hal sensors I guess. If I can make it not be super messy.

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flippy   10 kW

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Re: Hydraulic brake sensor

Post by flippy » Aug 02 2018 5:30am

TilmanBaumann wrote:
Aug 02 2018 5:21am
You are right. I will try to get some kind of analogue response by using hal sensors I guess. If I can make it not be super messy.
http://www.avdweb.nl/solar-bike/mechani ... witch.html

done properly you barely see it.
Lithium beats liquid dinosaurs.

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trazor   10 W

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Re: Hydraulic brake sensor

Post by trazor » Aug 08 2018 3:08am

I've brought one of these but not tested yet: https://www.amazon.com/gp/product/B015D ... UTF8&psc=1

I'm still running with this custom brake cut viewtopic.php?f=2&t=92618&p=1380593#p1380593

TilmanBaumann   10 W

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Re: Hydraulic brake sensor

Post by TilmanBaumann » Aug 08 2018 6:45am

Switch is easy. I got brake light switches. :D
The idea was to get a proportional response. But I realised that it makes more sense to pick up the brake lever position instead of brake pressure.

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