Ok. Fried 2, now what can I do for #3?

DogDipstick

100 kW
Joined
Aug 19, 2018
Messages
1,817
Location
Fleetwood Pa
I had a Cycle Analyst go bad on my bike. One day walked up to it, tried to turn the bike on, nothing. Dead screen. No smoke, or anything.

Took all accessories out, and hooked up the backup. #2. Blinked on fine, was happy. Took a ride. was fine.... began hooking up the accessories. All went well until I got to the last... the Tq sensor.

Whithin 3 min of hooking up the Tq sensor the new CA3 blinkenlighted OOT. This one let out a whisp of smoke right after the display got really bright.

Burned the diode in both, right after, the incoming power on the CA3board. I suspect a faulty Torque sensing bottom bracket is at fault. Its been through alot. Bike has had a rough beat up life so far... in a year of 3000 miles of fun and recreation.

So now I have #3 in hand. What can I do to make sure there isnt a fault in my harness or one of the sub systems? I suspect the TS, but it really might be a myriad of things.. I had it all on the accessories. The knobs, the bells, and the whistles.

Now I am afraid to plug anythng in cause I dont have another 115$ to spring.

Any quick tips, tricks, or hints on troubleshooting this issue ( immediate power draw on CA3 overpowering its internal regulators and causing damage)? From you electrical pros? Before.. well, you know?

Thanks in advance. Many, many, many thanks.

I got a new Tq sensor too. Might try install that. Think I may have to... I like the PAS.
 
is there a drain hole in the frame by the bracket?

can you hook up an 18650 cell to the torque sensing bracket with a 1 amp fuse to see if it blows ???

got this from Grin
https://ebikes.ca/shop/electric-bicycle-parts/torque-sensors/ncte-136.html

ncte_2up_p2.jpg
 
DogDipstick said:
I had a Cycle Analyst go bad on my bike. One day walked up to it, tried to turn the bike on, nothing. Dead screen. No smoke, or anything.


Took all accessories out, and hooked up the backup. #2. Blinked on fine, was happy. Took a ride. was fine.... began hooking up the accessories. All went well until I got to the last... the Tq sensor.

Whithin 3 min of hooking up the Tq sensor the new CA3 blinkenlighted OOT. This one let out a whisp of smoke right after the display got really bright.

Burned the diode in both, right after, the incoming power on the CA3board. I suspect a faulty Torque sensing bottom bracket is at fault. Its been through alot. Bike has had a rough beat up life so far... in a year of 3000 miles of fun and recreation.

What voltage is the system? Was the voltage upped just before the problem happened?


I always have a hard time remembering the details of this problem, but basically unless they have changed the regulation system in the CA3 since several years ago, it can only handle a certain amount of total power, so if there is higher voltage the current draw on it must be less. IIRC, I blew up my first CA3's regulator almost immediately with a THUN BB sensor because I had a high enough voltage pack (dont' recall...16s? would have to find my old thread about it) to exceed the limitations. Even though the CA itself will handle 100v, and everything is great by itself...if you hook up things that are powered *by the CA* thru it's internal regulator, like the 5v or 10v supplies, that's when they go POOF.

I'll post this now so you see it before trying anything else, and then I'll go see if I can find the thread or the info on Grin's site.


EDIT: found it here:
https://ebikes.ca/product-info/grin-products/cycle-analyst-3.html
PAS and torque sensors are only compatible with battery voltages lower than 52V nominal when the Cycle Analyst is providing power for the device. Connecting a PAS or torque sensor to the CA3 above 52V nominal voltage may cause damage.
Personally I think there should be a big orange sticker over the face of the CA or at least the PAS connector to warn anyone hooking it up not to do so under those conditions.

So basically under these conditions, if you have a 15s pack or higher, it's safer not to power the PAS from the CA (would need an external DC-DC from the main battery, or it's own battery).

If you have a 13s pack or lower, it's fine to power the PAS from the CA.

If you have a 14s pack, then it's in the middle of this warning, and would probably be fine, but if there is enough load from the sensor or other things connected to the CA's regulaor outputs, it could blow (and my guess is that if it did fail it would fail at power on, as that's when the most current flows in most systems as stuff powers up).

That said, my SB Cruiser has been running with a TDCM BB for years on 14s with no problems, max charge of 57.7v. I don't actually use the torque sensing because the CA won't allow me to use it the way I need to, (I am just using the cadence sensor in it) but it's still connected.
 
amberwolf said:
I always have a hard time remembering the details of this problem, but basically unless they have changed the regulation system in the CA3 since several years ago, it can only handle a certain amount of total power, so if there is higher voltage the current draw on it must be less.

EDIT: found it here:
https://ebikes.ca/product-info/grin-products/cycle-analyst-3.html
PAS and torque sensors are only compatible with battery voltages lower than 52V nominal when the Cycle Analyst is providing power for the device. Connecting a PAS or torque sensor to the CA3 above 52V nominal voltage may cause damage.
Personally I think there should be a big orange sticker over the face of the CA or at least the PAS connector to warn anyone hooking it up not to do so under those conditions.

Good info. I agree that there are limits that you have to be watching out for. Hard to power much off the battery voltage output, for instance, on the CA with such a low limit.

I don't think there's an issue with a cadence PAS sensor though, since the draw is so low, like a throttle. If it applied to all devices, then you'd think the caution would apply to things like dual throttles. The torque sensor PAS are a different story, since they actually draw power. The manual only has the caution under the torque sensor section.
 
E-HP said:
Hard to power much off the battery voltage output, for instance, on the CA with such a low limit.
Doesn't have any thing to do with the batteyr voltage output, just the stuff running off the CA's internal regulator (like 10v, 5v, etc).

The BV output doesn't go thru any of that, so loads on those don't affect the regulators. :)


I don't think there's an issue with a cadence PAS sensor though, since the draw is so low, like a throttle. If it applied to all devices, then you'd think the caution would apply to things like dual throttles. The torque sensor PAS are a different story, since they actually draw power. The manual only has the caution under the torque sensor section.

The warning says specifically:
PAS and torque sensors are only compatible with battery voltages lower than 52V nominal when the Cycle Analyst is providing power for the device. Connecting a PAS or torque sensor to the CA3 above 52V nominal voltage may cause damage.
so I would be wary of using either one above that point. Justin talks about this problem in several posts around the forum (teklektik might too), with the specific design reasons it happens, but i don't have a link ATM. If you can find one of those posts, it may help determine if it would be an issue or not.
 
I found the repair post I was thinking of..
https://endless-sphere.com/forums/viewtopic.php?f=2&t=19540&hilit=cycle%2A#p676523

amberwolf said:
I tried to check which wire on the Thun might've been shorted to the frame, but I cna't tell. It could have been blue or white easily, as there are several small nicks in each of those, but when I use an eye loup, someone else's old bifocals, and a magnifying glass in series to look at the wires under brighter lights, I can see at least one nick in each of the 5 wires, so it oculd've been any wire, or several. It might even be possible for them to short to each other, but the nicks aren't in the smae places, so probably didn't.

But it might nto have been a short at all. I forgot about this, from the first post of the CA v3 beta thread:
http://www.endless-sphere.com/forums/viewtopic.php?f=4&t=37964
The 10V bus can power the THUN sensor directly provided you are using a pack that is 48V or less. For higher voltages the CA's regulator would get hot and you'd want to feed the THUN 12V power from a DC-DC.
My pack is 66.2V hot off charger, and was at the time still almost fully charged, so that's a lot more than 48V. I shoudl've remembered that, before hooking it up, but I didn't, so that is probalby what killed the FET, and maybe whatever drives it.


I started trying to draw up the schematic but I kept losing my place on the PCB vs drawing, so haven't got anywhere on that yet. Gotta start work again tomorrow thru Wed, so dunno if I'll get back to this much before next Thursday.


I'm sure I have FETs that will work; I can probably use an IRFB4110 from a dead controller (or a new one if I have to--I have a few) just to test if it is all that is wrong, but I'm pretty sure it's not. Oh, and when i wire it in or solder in a drop-in-replacement, I'll have to run the gate wire directly to that resistor, as the pad seems to have come off with the broken leg. :roll:

Justin_LE's reply includeds repair info and schematic of that area:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=19540&hilit=cycle%2A&start=25#p678269
justin_le said:
amberwolf said:
I'm sure I have FETs that will work; I can probably use an IRFB4110 from a dead controller (or a new one if I have to--I have a few) just to test if it is all that is wrong, but I'm pretty sure it's not. Oh, and when i wire it in or solder in a drop-in-replacement, I'll have to run the gate wire directly to that resistor, as the pad seems to have come off with the broken leg. :roll:

Oh dear, well that was a short lived present! The regulator design is actually setup not just for any N-FET but a much rarer depletion mode mosfet, which are naturally in an ON state and require a negative gate voltage to shut off. This was the trick to get the CA to work below 10V in order to be compatible with 12V pack setups. So if you put in a 4110 or anything similar, you won't have nearly enough voltage coming out of the Drain to run the rest of the circuit. It could work but you'd have to replace the 9.1V zener diode Z1 with something more like 16V.

Here is the schematic for the linear regulator part of the circuit:
CA3 Regulator Schema.gif

To see if the rest of the CA is fine, just apply 12V power directly to where the output of the mosfet would normally be (or to the LED+ pin on the LCD header). If all is well it should power up to the splash screen fine, though it would then enter shutdown mode after that since the measured VBatt would be close to 0V.


I'd also forgotten about this, but I apparently just wired around the problem on mine, at least for testing:
Yes, it does work if I connect 12V to LED+ at the LCD connector, with ground at the spare GND pin at the edge of the PCB near that. For whatever reason, it doesn't actually shut off, though--it just says "Low V" after the boot screen clears. I haven't re-read the thread (or the new manual/webpages) to see if that's normal for a 12V-powered system.

So since the CA is also designed to run from 12V, then assuming it is safe to do this, I will just:

--wire up a 12V anderson tap from my 12V lighting pack into the CA and run it from that,

--leave the FET out

--connect the traction battery via the normal controller connector

--connect the Thun power wire to the 12V pack instead of to the CA's 5-pin connector (although I could just disconnect the wire off the CA PCB "10v" pad and connect that wire to the 12V CA power instead, I guess).
I didn't go any further in that thread tonight, but the "low V" error I assume I fixed by changing that seting in the CA to less than my lighting pack's voltage.
 
Just my 2cts.

My MTB conversion has the early CA3 in use. I use a generic Chinese PAS with 12 magnet disc. (5v source).
Using Grin 1mOhm shunt. Low setting.
Battery pack is 58.8v fully charged.
Other connections are throttle and brake cut off.

My Stealth type bike has the later CA3 (10v PAS) and the PAS I am using is the Grin mini 24 magnet one.
Using 200amp 60mVolt shunt (0.3mOhm) using high setting.
Battery is 92.4v fully charged.
Other connections are throttle and brake cut off.

My MTB has been in use almost daily for the last 5 years (approx. 11,000kms). During that time I have had 2 of the PAS pick ups stop working. Replaced them and no problem.
Mt Stealth type bike I have been using for about a year now (approx. 800kms).

I have never had a problem with either CA3. Although apart from the 5v throttle and 5v / 10v PAS, I don't use any other take off from the CA3.
I admit this is through ignorance of not reading the voltage values published by Grin, but 5 years and 1 year seems to me to be pretty reliable.
 
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