Solving the Variable Ebrake-Throttle Problem

[Kingfish]

You can't conclude anything from that test unless you have already measured a few known good 7805s.

OK, but the issue that I'm having is trying to set R4 to 10k. I set it before soldering, but after it read 3.XX. I tried to dial it back in, but I could never get to the point where I wanted, so I removed the wires and remeasured just the POT solo and it was adjusted clear up to 18k. Now the 7805 was isolated and that's when I was able to read the voltage across the +5V lefg and GND. Maybe what I aught to do is calibrate R4 first, then solder - and go have a beer & not worry. :wink:

Tomorrow's another day. KF

 

[Njay]

Once you put a resistor in a circuit, the circuit will of course change the value you read from it, but its value doesn't change.

 

[Kingfish]

Once you put a resistor in a circuit, the circuit will of course change the value you read from it, but its value doesn't change.

You are absolutely right. I think the two active brain cells in my head were starving for air when I wrote that down... certainly they were starving for food.

Weather sounded nasty this early AM waking up, but the weatherman says I've got a good window holding until about 2 PM. Geese are going bonkers as they head south.

Back to the board:
Disconnected +5V from R4 and reset to 10k, then attatched the Prototype to the bike and tested 7805: Good voltages. U2-A+ reported as +0.29V which seems low; it should be +0.456V. SS (not yet SS-OUT) has +0.26V sitting static. Selected Ebrake the the FH jumped forward as if I was hitting throttle; repeated 3X and same result. Disconnected Protoytype. Retested both controllers with very light throttle and both wheels spin, so no harm done. At this point I am going to remove the controllers and add Q2/R2 to both for protection. Make sense?

~KF

 

[Kingfish]

Crossroads

I applied the Q2/R2 mod to the RH controller; tedious but done. Partly disassembled the FH controller; the phase wires are still attached, however a visual inspection reveals that my extra sense wire to that controller has not ever been used and is N/C. The FH controller has long phase cabling that runs the length of the top tube and down the forks. This is not a small job; probably an entire day to remove everything, apply the mod and then reassemble.

Arrrg! I just want to know if the mod works.

I think I'm just going to leave the FH controller alone for now since it is unaffected. That means the jolt I felt when Ebrake was despressed during the static test came from the RH. Right, so it all goes back together and we recalibrate - get the voltages where we want, ensure the circuit is working properly before dynamic test, disconnect the FH phase wires, and proceed from there. Give me an hour.

~KF

 

[Kingfish]

Test Drive

Well, let me begin by saying it was not what I expected.

Without Prototype Attached:

• FH stutters and cuts out. This controller does not have thread mods applied.
• FH regens normally.
• RH stutters, and when FH drops out, RH runs smoothly.
• RH regens normally with one caveat: At low speed - and I mean all the way down to ZERO mph I can feel it PWM regen; it does not cut out, but does feel very cavitated towards the end.

Therefore I have to presume that the Q2/R2 mod is affecting RH controller Sense even when the Prototype board is not attached. I have no idea why the FH is stuttering. They share –EBS and SP.

With Prototype Attached:

• FH – no throttle.
• FH regens normally.
• RH – no throttle.
• RH regens normally.

Unplugged Prototype and drove back to the top of the hill – all the way to the very top for regen test. Plugged in Prototype and coasted ½ way down with very good speed and hit ebrake: Strong regen in both motors, difficult to conclude if it is any stronger than before, however rolling Throttle during ebrake had zero effect.

Back to the top of the hill for Round 2, this time selecting ebrake with Throttle in different positions – no effect. Just one level of braking. Both motors regen about the same rate, and as I stated earlier, the RH has the thread mod applied.

Conclusions:

• FWIW, I think we discovered a way to regen all the way down to zero speed. It wasn’t a very smooth experience, which suggests why the ebrake normally cuts out near the end.
• The no-throttle business possibly indicates we are over-compensating the Sense. Why both motors fail to throttle when the Prototype is attached is a mystery to me, but I don’t wish to continue experiment without first understanding why the RH Q2/R2 mod is affecting the FH.

Now that I think about it, the RH Q2/R2 mod could be affecting –EBS when the Prototype is attached, and not allowing Throttle, but we have regen. However – the Prototype presently fails to affect regen – which is the primary goal.

Why do I get the feeling I’m flogging a dead horse?

Anyways – I need to isolate the FH problem and to do that – I’m going to back out the Q2/R2 mod on the RH controller. There has to be a better way to share Sense when -EBS goes to GND.

~KF

 

[Njay]

Humm, I see now what you're trying to do with R2/Q2 SS-IN/SS-OUT. Remember when I told you 2 or 3 times that nothing can be between the OPAMP's output (U2-A) and SS? Use another OPAMP buffer to connect the 2nd unit.
Furthermore, Q2 cannot be used as a switch for an analog signal, and specially not one with so low voltage.

Did you put the diodes on EBREAK as you were telling about in the first pages of this topic?

 

[Kingfish]

Hi Njay

Q2/R2: Yeah, something altogether different. Not going to worry about it for now cos I’m only going to mod one controller to keep the research simple, and if we get success – then worry about mating two controllers. :wink:

Diodes: If you look at the last schematic at the EBS Emulation, far left, there’s a +5V out with D0 1N4148 inline. That diode exists on the controller board, so I did not add another one.

FH Stuttering: I found the source of the problem; The SC HE Signal wire broke off at the solder joint on the controller PCB, likely my fault when I inspected the board for the Sense mod. All of those wires are under strain when there should be none at all – so I’ve clipped them and am now in the process of soldering in small extensions. I have to tell you honestly that I thought I had a blown controller. I’ll know for sure though when the repair is complete later today.

But talk about having a fright though, and right before Halloween. So – to affect the inspection and possible replacement, I had to remove the entire triangle fairing and battery pack. I was just saying on another thread eariler that if I ever had to dig in that far into the bike I’d move that pack backward an inch to gain more maneuverability at low speed and for parking. Well, I’m eating crow now. What I should do is cut the long motor umbilical and make it real convenient to R&R the FH controller like the rear; make it identical so I don’t have to do this again. Sheesh; how laborious.

Anyways – that’s where I’m at: Knee deep in repair. Once I get the FH sorted, then I can look at Sense again.

This work is making me thirsty. KF

 

[Kingfish]

FH Stuttering: Resolved - fixed. Broken HE wire. Passes Freewheel test with flying colors.

Bullet dodged.
Onward... to the pub, KF 8)