Search found 943 matches

by rew
17 Feb 2018, 15:36
Forum: Related Hardware
Topic: Energy dump / overvoltage protection
Replies: 24
Views: 6285

Re: Energy dump / overvoltage protection

The DRV is a 60V chip. It breaks when you go over 60. Going for 68 is sure to fry the chip.

There are also diodes around the DRV that are rated for 60V. Those might be the cause of the DRV getting fried.
by rew
17 Feb 2018, 12:12
Forum: General
Topic: current measurement with 2 shunts?
Replies: 3
Views: 651

Re: current measurement with 2 shunts?

When in BLDC Mode, you drive two phases, and you want to measure the voltage across the third winding to help with finding the moment for commutation. So you have to measure the voltage on the phase. You can also measure the current, for example to be able to do a current feedback or in an attempt t...
by rew
11 Feb 2018, 16:47
Forum: For sale, orders, etc.
Topic: MINI compatible with VESC® Software
Replies: 46
Views: 13103

Re: MINI compatible with VESC® Software

And the STM32FxxxCxxx processors have 48 (or 49) pins, while the STM32FxxxRxxx have 64 (among which is the STM32F405Rxxx on the VESC).
by rew
11 Feb 2018, 15:47
Forum: FOC
Topic: VESC FOC for a flywheel application....
Replies: 14
Views: 2403

Re: VESC FOC for a flywheel application....

Still I've been thinking lately.... Those TRENT1000 motors have 3m diameter turbine-disks running at 14k RPM.....
by rew
11 Feb 2018, 15:40
Forum: General
Topic: current measurement with 2 shunts?
Replies: 3
Views: 651

Re: current measurement with 2 shunts?

I have a clamp ammeter. It is fun to test the new hires here: With the motor current set at say 10A, you put the clamp on one wire. 10A. Next wire: 10A. Now those two wires together... How much do you expect? The answer is: Again 10A! The two sines of 10A RMS add up to a third sine of 10A RMS. And t...
by rew
11 Feb 2018, 15:20
Forum: General
Topic: Parallel FETs
Replies: 3
Views: 548

Re: Parallel FETs

Even with a half-h-bridge-power-board with the fet-driver on the board, a guy claiming to know about power electronics said: "your fet driver is too far from the FET". And that is with me doing my very best to get it as close as possible.... So simply taking an existing VESC and connecting...
by rew
28 Jan 2018, 11:47
Forum: FOC
Topic: VESC FOC for a flywheel application....
Replies: 14
Views: 2403

Re: VESC FOC for a flywheel application....

rew, that's interesting: can you elaborate a bit on that? I.e. what has been fixed in newer firmware that enables higher ERPM? My belief was that it was the three shunts of VESC6 that enabled it to run at higher ERPM, but my understanding of this is fuzzy at best. :oops: I just remember Benjamin sa...
by rew
28 Jan 2018, 11:44
Forum: General
Topic: raspberry pi electric skateboard
Replies: 3
Views: 594

Re: raspberry pi electric skateboard

From your description I get the impression that you are setting the dutycycle from some sort of throttle. Many people have found out before you that this does not result in a comfortable ride.

The idea is that the throttle controls the current through the motor and therefore the acceleration.
by rew
22 Jan 2018, 09:43
Forum: FOC
Topic: VESC FOC for a flywheel application....
Replies: 14
Views: 2403

Re: VESC FOC for a flywheel application....

You can even run the latest firmware on older hardware to increase the achievable ERPM limit. (It's a software issue, so a software fix will fix even old hardware).
by rew
13 Jan 2018, 11:17
Forum: FOC
Topic: DRV8302 faults with FOC
Replies: 27
Views: 14431

Re: DRV8302 faults with FOC

The "low ESR" is a secondary property of the capacitor. There WAS an issue with a capacitor being "marginal" on it's primary property: capacitance. When that happens, you simply need the bigger (in capacitance) capacitor!

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