I have searched long and hard to find either an OEM or aftermarket ELECTRONIC brake proportioning valve, there are none, only manual valves. I have read that there are some cars out there (including Hondas) that have factory fitted, electronic braking force adjustment systems that use an electronic control system to adjust the hydraulic brake proportioning but I can't find one of these [size=13px]valves[/size] anywhere, new or used. Some of these systems incorporate this feature into the ABS system, making it hard to develop your own system utilizing their components. Even if I could source a true electronic proportioning valve, the task of designing and building the electronics to control the oem components would be very daunting.

So I want to build my own. I want to use a Wilwood Adjustable Brake Proportioning Valve (Part #: 260-11179) along with a stepper motor, micro-controller, stepper motor driver & a multi position rotary switch to be able to control the brake bias from inside the car. (Much like TEIN's Electronic Damping Force Controller for on the fly damper adjustment from inside the car). This would mean the rotary thumb screw of the manual proportioning valve would be operated by the stepper motor and controlled via the rotary switch. I don't have the Wilwood Proportioning Valve in hand so I don't know the number of turns it has from fully threaded in to fully threaded out but I want the system to be able to electronically set anywhere within its full adjustment range. Theres a problem with this though, the manual valve has adjustment that takes place over multiple, full turns of its adjustment **** and most stepper motor systems only take one full turn of the shaft into account when it comes to position and stepping and can't communicate multiple complete turns to their controllers. I'm not sure how to overcome that, I guess I could use a very advanced controller that can work with a Incremental Rotary Encoder Switch that would allow for multiple full turns and would stop the stepper motor at the manual proportioning valve's, full forward bias and full rearward bias settings. Either that or use an additional circuit along with an advanced controller that would do the monitoring and relaying of the physical valve position via position sensor(s).

I need major help in designing this circuit. I know very little about the HUGE variety of microcontrollers out there along with the stepper motor drivers. I know I need both, along with a rotary switch, maybe some sort of electronic display (I'd like to at least have a LCD display that shows a value relative to motor/valve position) and the stepper motor itself which would need to be able to have enough torque to turn the Wilwood valve and would need to work with the incremental rotary encoder switch to make multiple full turns. This is VERY complex circuitry to design and get working and I don't quite have what it takes, there are such advanced microcontrollers with such complicated specifcations and options that I am at a loss and need someone with extensive electronics knowledge to chime in. Google [size=13px]searching[/size] for me anyways is hitting a wall, I can't get a definitive answer as to what is needed to make this happen.




Thanks guys,

-Ian

 

This appears to be a common stepper motor driver chip:
The Allegro A4988

 

I found this @ Pololu.com:
They are "Stepper Motor Controllers" with Built in Drivers:
Tic 36v4 USB Multi-Interface High-Power Stepper Motor Controller


This would work to control the stepper motor but would still need a microcontroller to interpret the absolute rotary incremental encoder switch.

 

I found this @ Pololu.com:
A "Stepper Motor"
Stepper Motor: Unipolar/Bipolar, 200 Steps/Rev, 57×76mm, 8.6V, 1 A/Phase

 

Here is some of my photoshop work, I created a carbon fiber switch panel for my twin turbo, j32a2, 6-spd, RWD conversion on my BB6 Prelude. See my plans here: https://honda-tech.com/forums/hybrid...elude-3323331/
I am mainly sharing this for the visual on the Brake Proportioning Rotary Encoder Switch & Bias Indicator Display.

 

This should make for a system to electronically control the brake bias front/rear from the driver's seat, with a 20x4 LCD display that will display the current percentage front to rear. The stepper motor I chose should be able to handle the torque required to turn the Wilwood proportioning valve but will require a custom mounting plate.
The microcontroller and driver have settings for max current, so the system will automatically cut power to the stepper motor at the fully forward and fully rearward positions of the proportioning valve.
The rotary encoder switch I chose is absolute so it will retain the settings even with the system or car being turned on or off.
The microcontroller will be powered by USB, with a hard wired 12V DC -to- 5V USB adapter

 

Here are the final components I have picked out and a wiring diagram I made (It's probably got wrong connections all over but oh well).

Microcontroller: ARDUINO MEGA 2560 REV 3
Stepper Motor Driver: AUTOMATION DIRECT SureStep STP-DRV-4845
Stepper Motor: AUTOMATION DIRECT SureStep STP-MTRH-23079 NEMA 23 Frame, Single Shaft, 5.6A, 286 Oz-In Holding Torque, 1.8-Degree Step Angle, 200 Steps Per Revolution, Bipolar
Microcontroller Power Supply: Powerwerx USBbuddy 12V DC -to- 5V DC USB Power Supply
Stepper Motor Driver Power Supply: CUI Inc. VHK-150W-Q24-S24 150W DC-to-DC Converter
LCD Display: SunFounder IIC I2C TWI Serial 2004 20x4 LCD Module
Rotary Encoder: BOURNS EMS22A50-D28-LT6 ABSOLUTE ROTARY ENCODER

 

Follow my online posts and discussion on All About Circuits.com here: All About Circuits - New to Electronics-Stepper Motor, Drives, Microcontroller, Rotary Encoders