Quick e-brake question

[Obiwan007]

I'm getting ready to convert my hydro brakes to e-brakes via a reed switch. This seems pretty straight forward to me but I want to use a micro-miniature switch and I am not sure about the current necessary. I know that the brake operates off of 5V but how many amps? I was looking at switches that have the following specs.

Configuration: SPST
Maximum Switch Volts: 30v DC
Maximum Switching Current: 0.05 amps
Overall Length: 1.05 inches
Glass Tube Length: 0.2 inches
Glass Tube Diameter: 0.055 inches

So is .05 amps too low? Am I going to blow this switch if I use it as the e-braking switch? How many amps does the brake signal draw? Is there another switch that is this small (I like the .2" tube length) that would be more appropriate?Appreciate any help, Obiwan.

 

[biohazardman]

You could jumper in a small multimeter, between the wires, and go for a ride to find your minimum needs but my guess is it is higher than that. I have a 1A, 20W reed switch, a bit over an inch long by 3/16ths wide on my brake cutoff switch. It has lasted for over 10K or so on my geared motor. Overbuild it if you want it to last.

 

[Kepler]

The load would be milliamps. Not enough to worry about. Practically any mico will do the job.

 

[alsmith]

I would expect it to be fine- that switch is only sending a signal to the controller, not carrying any load.

 

[biohazardman]

I actually got mine in a three wire so I could eventually do an LED brake light so wanted something that would carry a small load. Never really gave much thought to the signal amperage being so low although it makes since as it is after all just a signal. Still even though I never did the brake light thing, building another bike now so probably never will, the 1A switch is small, inexpensive and easy to work with so no loss on my part.

 

[Obiwan007]

Thank you gentlemen. I ordered some of these since they are cheap. I'll install one and see if it works before I permenantly epoxy it in. Obiwan.

 

[rogerc]

How hard is it for an electronic idiot (me) to take my existing brake and turn it into an ebrake. My Giant has one of those set ups with both the shifter and brakes in the same housing. I want to keep this set up but make them ebrakes.
What do I have to purchase and how to wire or in?
This souls make my build really clean.
I am using the ebrakes from cell_ man and don' t know how they are set up. Also using a CA 3.0 which I think the ebrakes plug into. Haven't got the kit yet should come in about a week.
Thanks for the help this would really help me out.
RC

 

[d8veh]

Use these if you have cable brakes. You only have to slide them over the cable inner after shortening the outer by 2". They need power, so you need to add one wire by splicing it into your throttle red or PAS red at the controller end. Many of the newer controllers already have the three wire connector for them, so plug-and-play.
http://www.bmsbattery.com/accessory/459-hwbs-hidden-wire-brake-sensor.html

 

[Obiwan007]

I'll let you know how hard it is regerec as I too am a reforming electronic noob. Got the switches in the mail today and will be doing some testing tonight. Need to build in some adjustability so I can dial in when the regen kicks in.

 

[Obiwan007]

Doing some tests I found that the switches in my current bike brakes work properly in the normally closed state when the brakes are not being applied. And normally open when the brakes are applied. This works good with my Lyen controller. My current build is also going to have a Lyen so I will need to arrange this switch so that it is close to the magnet when at rest and moves away when the brakes are applied. Pics comming later since I won't be ready to hook them up for some time on my build. I'm wondering if the CA3 uses this same arrangement since I know that some controllers are opposite. Vary body know? Does the CA connect via a two wire system or a three wire?

 

[alsmith]

I'll let you know how hard it is regerec as I too am a reforming electronic noob. Got the switches in the mail today and will be doing some testing tonight. Need to build in some adjustability so I can dial in when the regen kicks in.

The switches work when the cable moves, a cable adjuster won't affect it.

 

[Obiwan007]

I think rogerc and I are talking about hydro brakes so the in-line switch won't work for us. I have read that there is an in-line hydro brake switch but it will deteriorate with the dot 3 fluid in my brakes. So reed switches it is. I intend to use izemans method here:
http://endless-sphere.com/forums/viewtopic.php?f=3&t=38848&start=30#p691975

 

[wheebikes]

How do the in-line switches know when to restore power to the motor? It seems like you'd get something like:

- Brake open, motor has power
- User pulls brake, motor power cut
- User holding brake, power restored?
- User releases brake, motor power cut again

I want to use these to make drop brakes work with a bafang motor, but I'm not sure I get the mechanism.

 

[r3volved]

You press brake and it toggles the switch...release brake toggles the switch...
So no brake = motor on, switch off.
Apply brake = motor off because switch is on

it's a momentary switch using a lever instead of button

 

[d8veh]

How do the in-line switches know when to restore power to the motor? It seems like you'd get something like:

- Brake open, motor has power
- User pulls brake, motor power cut
- User holding brake, power restored?
- User releases brake, motor power cut again

I want to use these to make drop brakes work with a bafang motor, but I'm not sure I get the mechanism.

You don't need to know that. It's all smoke and mirrors. The main thing is that they cut the power when you apply the brake and restore it when you let go of it. they work perfectly. One thing, though, you have to install them the right way round otherwise they cut the power until you apply the brake.