The power boards have finally shipped! Should arrive on Monday.
In other news, I spent quite a lot of time improving the logic board.
Replaced the 1A 5V buck with a new one that can do 2.5A average / 3.7A peak which is much better, although slightly more expensive LM5164 -> LTC7103, The input to the 5v buck now has a transient filter which clamps overvoltage spikes and smooths out the noisy input to put less stress on the part.
Added another two 5v->10v chargepumps so now there is room for 3 in parallel, allowing for up to 120mA on the 10v rail. Added a bunch more capacitance as well to reduce droop when the fets were switching at 60khz.
Added 220R CAN termination resistor which I forgot before.
Added 10k pulldowns on the ADC inputs to stop runaway devices when throttles become unplugged.
I managed to squeeze in the holes for the shield on the interboard connector, as it seems to be impossible to get hold of them without the shield (apart from buying ones with shields and taking them off). Which should make it easier to get assembled.
Added a feed through from the USB 5v to allow the logic side of the board to be powered by just plugging in USB. This means you can change settings, etc without needing external power. It is protected by a polyfuse and a 100V 3A schottky to stop it blowing USB ports up.
Added USBLC6-2SC6 to the USB connector to protect from ESD.
Finally got the silicone wire guard the right size and casting properly in the 3d printed mold.
Added a loop next to the connector to allow fitting a cable tie or something for strain relief.
Looking nice. Keep up good work!
I had issues with 3.3v dropping to much on my controller as I am also powering esp32 that can chew up up to 700mA when actively transmitting over wifi. Then replaced to another LDO and it's been stable.
I have had USB power tied with the 5v rail from day one of prototyping and had never had issues. Seems like a diode between the USB and the rest of the circuit is all that's needed. Very convenient to program and test virgin boards. Not sure why this is not standard on all VESC.
Yeah I had it connected at the start also, but removed it after connecting my power supply the wrong way round one time and it blew the diode up! Hence the polyfuse and slightly overkill diode current rating.
Don't think I have had any problems on 3.3v so far, got the STM32, IMU, BLE on there, but probably not much more than 200mA with it all going. Its just a 600mA LDO which I have used on all my boards from the beginning. (Don't understand why the official ones use bucks for everything, just more inductors to fall off in shocks or vibration)
The VESC 6 / 75/300 have a real problem of blowing up the STM32 if you put the sensor wires together with the phase wires. I don't understand why they have 0 protection for esd or any other transients. Especially given how many nice exposed io pins there are and how cheap tvs diodes are.
I will probably add some current limiting resistors on the IO before it gets to the tvs as well.
Very nice! Shouldn't the CAN termination resistor be 120ohm?
Yea the ESP32 draws a lot of current, but not really that much during transmitting. When starting wifi, it draws a huge current for a short time. It is recommended to use a capacitor on the 3.3V side close to the board. I used the ESP32 on the A200S, and the ESP32 sometimes gets stuck when starting up wifi.
Really looking forward to those power boards!
Well yes its supposed to be 120ohm... but I looked at vesc 6 schematic also and it has 220ohm?! My guess is so that if you have a bunch of vescs on the bus it doesn't have a problem with the resistance going too low.
Yup. It won't matter anyway, as you don't really have long cable lengths in a typical vesc application.
Power boards arrived, built one up to make sure everything fits. Now need to assembly a new logic board to run it.
Looks good, I am looking forward to see it run! Hope all goes well.
Beautiful, I am looking forward to either buying or building one of these.
Tested the power board today without a heatsink. From 25C it managed to do 200A for 60s before thermal throttling down to 100A continuous.
Motor is a TP Power 5860.
Looks great! How does that energy-wasting work, it seems you just have a motor spinning freely?
Its foc openloop. Which drives current in the d axis. So it makes loads of heat but doesn't produce any torque. Which is perfect for this type of testing as you don't need a load. Just a motor with low enough resistance that it doesn't heat up too much. (Hence the fan)
Alright, makes sense, thanks.
100A phase current continuous without any cooling or big mass is very impressive
Have you tried how much current it can drive continuous without the copper bus bars?
The bus bars are only on the battery side, just to give more surface area in contact with the heatsink really. The copper on the board is so thick it doesn't really need them.
The phase connections are just on the pcb tracks and no bus bars there, so this test won't really show any difference with or without them anyway. I am doing proper dyno testing at the weekend with two at 12s, should be able to get some good logs from that.
Also fun that this 100A cont was even without any heatsink, so if I replicate Benjamins setup for testing the 75/300, by clamping it to a big aluminium plate, I should see what it can really do.
when you plan to start sell a test boards for beta/ first users? I am very interested to participate. What is expected price?
Price will be £399. Pre-order discount still to be decided, but likely to be about 5-10%.
Hi All - I've got two A200s V2 units that I am looking to sell, unfortunately they didn't work for my application. One unit has never been powered, the other was only used on a test bench.
Looking to sell for $300 USD + Paypal fees. They are located in Gainesville FL USA, and can be shipped immediately.
I can be reached quickest via email, firstname.lastname@example.org
No the firmware is not compatible between the versions. I will add the firmware to github after release.
wow those power pcbs look cute.
What are they ? normal fr4 with 4 layer ? or something fancy
8layer fr4 tg180, 3/4/4/4/4/4/4/3 oz, 3mm thick.
Want some FR4 with your copper there?!
Now avaliable for preorder.
Have you tried to use thinner copper layers or less layers? 4 oz @ 8 layers is pretty expensive. How much current would be possible with a cheaper PCB?
I used to use 2oz 4 layer boards, but they don't really have low enough resistance or spread out the heat very well. The boards are not too expensive when you order at larger quantities like 100+ boards. The performance increase by going for such boards is huge. Well worth the extra expense in my experience.
Congrats! Have been watching this project for a bit and glad it's ready for preorder. Do you have more information about the preorder? Are the boards assembled and ready to be shipped, or are you getting enough orders together to make a bulk order at the fab?
Also, does the open source project on Altium represent the current state of the board, with all modifications you made during testing? Has anyone made one for themselves yet?
I have 100 power boards already and the mechanical bits (heatsinks, cases, bolts, etc). The preorder is so I can get a large order in for the logic boards to get the cost down to a sensible level. Plan is currently to put the order in by the end of the week, just doing the usual too and fro with the pcb fab at the moment. One of the main things I did over lockdown was acquire all the assembly kit I need to do the power boards here, as that lets me order the mosfets to order.
The altium project is the current state of the board, I update it everytime I make any changes. Although I have seen a few people making forks and removing all attribution which is a bit disheartening when you spend so much time on something. For now I changed the license on the project, but it doesn't stop the likes of flipsky and maker-x just rebranding it.
Thank you for your hard work on this project. I will put in an order and look forward to receiving it when it's ready. I'd also like to have a go at making one or several myself, and am very grateful for your willingness to open source your work. I know of no other comparable VESC design which is equally open. Your commitment to making the design available is laudable.
I'm sorry there are folks forking the project without attribution. I think people in the community can recognize quality, and hopefully reward the designers of new boards with their business.
can you give us an update on the Preorders?
Really enjoying the spam...
I have logic boards now, final heatsinks arriving in the next few days (delayed by brexit grr). Need to cast more silicone parts, but should get that done over the weekend.
Aim is to ship the first unit on monday all going well.
My beta testers found an issue with the shunts where at high current (260-280A) they would desolder and moved due to vibration. This caused the low side of one of the phases to be disconnected and started an arc which destroyed the unit. After investigation I noticed that the pads for the shunts on the board were far too small and too far apart, so only a very small amount of solder was actually connecting them. Additionally the vias on the pad was causing all the solder that was there to wick down the holes.
So to fix this I changed from dual 0.5mOhm 2512 shunts to a single 0.2mOhm 2715 shunt. This reduces the heat produced and is slightly larger so has better contact with the pad. I also scrape off the solder mask to make the exposed copper pad larger. Once the reflow is done with the stencil I then add a lot more solder paste and make it a really solid connection. Then while its still molten push the bus bars into the shunts to make a much better current path. It should also act to heatsink the shunts better and stop them desoldering and moving.
Looking nice, great progress.
What is the power rating on those shunt resistors?
I've been looking into using shunts but excessive power dissipation has been a concern.
They are 4W I think, 2725 size. I have the heatsink touching them with high performance thermal pad.
Can't decide which one is better between these two pads, so ordered both to do a test. Just using some thermal grizzly kryonaut at the moment, so interested to see how they all compare.
Don't have very even clamping pressure, the outer phases have much higher force than the inner one. So need something that takes basically no force to get good results.
oh wow that is looking great, but price 400 GBP🙈🙈🙈 I'm so sorry to say it is beyond reasonable cost :( spintendpower is a lot bigger, but also 16s and also high current controller (some people have reported DC current to be 80-100amp (40-50amps per controller and no issue while phase current in about 150amps per controller without issue) and it is 200gbp = 100gbp per 1 channel.... I'm not poor and really just need single channel controller, but its hard to find arguments to pay 4 times more.. if any one is selling used one I would be interested because I cant find any other good 1 channel VESC6 based (beside may be Flipsky FSESC 7550 75V 160A - don't know if rating is DC or Phase current)
Hi, I am making my custom vesc based on vesc 75/300, the only difference is one shunt per phase, I had problems with the firmware, in the beginning I downloaded the original vesc 75/300 firmware, at the first start I managed to spin the motor but there was noise, I decided to compile the firmware for my board and correct the shunt resistance in the hw_75_300.h file, after loading the new firmware nothing changed, I tried to change #define CURRENT_SHUNT_RES, but any resistance values do not change anything, after some testing I realized that the displayed current is more than three times from the actual. How can I change the resistance of the shunt, maybe I'm doing it in the wrong place?
Here is the engine detection on vesc 4.12
My board detection
I can run foc_openloop 160 200, but the phase current and battery values are not correct, my multimeter at the input shows 4.8A and vesc shows 17A
So you are complaining that it is too expensive, but then also you can't find a controller that matches the spec and power output of this controller? Sounds like it is worth the money then as it can handle higher current output in a smaller package than any other controllers on the market.
And its designed and built in the UK, instead of a chinese clone
Where do you order PCBs with those specs from?
PCBWAY, you need to order 200+ or the price is insane per board.
any idea how much copper plating is in vias?
I like to est my design, but every time i try foc_openloop, it works for few seconds and then shuts down, no fault or overtemperature...
How do you make foc_openloop work continuously
Turn on heartbeats before running the command, heart button on the right.
I will try that today..
How much mottor heats wile testing with foc_openloo, and what erp did you test your setup?
Any chance there will be a 100v version? 12S is fine for a skate board or maybe a slow e-bike, but I've not built at 12S in many years. Most of my builds are 20S.
DIY Zap scooter build...20kw peaks.
Im thinking on using one for my ebike project. How did you do the calculation on the capacitors? I found that these caps probably get too hot if running on 200Arms? Have you ever experienced or measured some issues with the heating of the capacitors? Do you know which stray capacitance you have in your power loop?
I have a question regards power stage design which I'm studying. Am I right in looking at your layout that you do not really laminate the bus with alternate +bus,-bus,+bus,-bus layers to reduce inductance, and your multi-layer board is really just so you can get enough copper thickness? If so is this design choice because the design is so compact that the bus inductance is low anyway?
Merhabalar, Ankara'dan size katılıyorum.Esc ile ilgili yaptıklarınızı hayranlıkla izliyorum.Elektrikli sörf tahtası ile ilgileniyorum. sss5694 12000w kv800 motor kullanıyorum.
a200s v3 vesc power board yapmak istiyorum.Logic board pcb parça listesini bulamıyorum. Bu konu hakkında bana yardımcı olabilirseniz çok sevinirim.
Güç kartı ve mantık kartı pcb'lerini nasıl sipariş edebilirim ?