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You do NOT want to tell both motors to do the same speed. Any minor error will cause the motors to fight each other. With PWM control, you get a slightly better situation. The effective resistance of the motors will allow them to adjust a bit to small errors. Still it is quite possible that one moto...
Looks nice, but read my posting from 15 months ago: You are not effectively cooling the mosfets. any heat generated inside the mosfet has to travel through the 10x higher thermal resistance to the outside of the FET.
I asked TI about providing the PVDD externally. They answered! The response: DO NOT DO THAT! That might be (and probably is) just CYA policy, but that's the official word.... (I use a DCDC converter in an application. The datasheet says: "min load: 10% of max load". In my application the l...
- 02 Dec 2017, 20:30
- Forum: VESC Projects
- Topic: VESC in homemade lathe/drill press
- Replies: 11
- Views: 942
Yes. The torque constant is actually the same as the motor constant Kv. Or depending on the units the inverse (*). 245Kv is 245 RPM / Volt = 245 (RPM/V) / 60(sec/min) * 2*pi (rad/rotation) = 25 rad/sec/V That means the torque constant is 1 over that, or 0.04 Nm/a. So for 40A you get: torque = 0.04 N...
I have had my lab powersupply backfed from braking the motor. Once with the powersupply at its max and a few times less agressive with some margin on the powersupply. But yes, the VESC will remain powered even if it cannot drive the fets as long as the motor turns....
- 02 Dec 2017, 19:26
- Forum: General
- Topic: 180 degree commutation with sensors vs standard 120
- Replies: 13
- Views: 1203
No, From what I read above, the "180 deg commutation" is simply BLDC but with an extra motor coil powered up. (Y or Delta does not matter). But if we think about what we want to achieve.... We have a permanent magnet in an electromagnetic field. We want to set up that magnetic field that h...
Nathan wrote:have very high inductivity - 12000mH.
That is VERY high. So if we apply 12V, after about a second the current will have risen to 1A. So more than about 20 - 30 RPM is imposible with this motor. Are you sure?
- 20 Nov 2017, 09:15
- Forum: General
- Topic: Error: read version failed when trying to use OpenOCD 0.7.0 with STM32F407 Discovery Board As Programmer
- Replies: 5
- Views: 1807
Re: Error: read version failed when trying to use OpenOCD 0.7.0 with STM32F407 Discovery Board As Programmer
The discovery board is a reliable programmer. First try flashing the BLDC firmware into the CPU on the discovery board, then try removing the jumpers and making theconnection to the VESC. So this way you know for sure if it is software you're having trouble with or hardware.
I messed with the switching speed. No real effect. Still craps out around 50% duty cycle. Is there any way to start in FOC and switch to BLDC at a certain RPM?? With the current firmware: Definitively no. Switching from one side to the other in the current setup means that the "other" str...
[remember in the scenario the customer states his requirements include at least 30mph on flat ground, and greatest range while repeatedly accelerating full throttle in start and stop traffic.] So, your rider is allowed to press full-throttle, but the motor controller will, in the interest of effici...