Search found 926 matches

by rew
04 Mar 2018, 10:12
Forum: General
Topic: General questions
Replies: 12
Views: 1044

Re: General questions

Dor, please ignore Devin. He's got some non-scientific ways to get some results that are not scientifically valid. He starts out with assuming a gear ratio. That's the last thing you need. The motor can put out 2500 Watts. If we take that to be correct, the main question is: Can you do 15mph on 2500...
by rew
25 Feb 2018, 17:27
Forum: For sale, orders, etc.
Topic: MINI compatible with VESC® Software
Replies: 45
Views: 7517

Re: MINI compatible with VESC® Software

That datasheet quite conservative:
Lead Temperature for Soldering Purposes
(1/8″ from case for 10 s)
TL 260 °C

I would guess that it is safe for the soldering iron to be 1200 degrees at 1/8" from the case, for much longer than 10 seconds.... :lol:
by rew
17 Feb 2018, 15:44
Forum: For sale, orders, etc.
Topic: MINI compatible with VESC® Software
Replies: 45
Views: 7517

Re: MINI compatible with VESC® Software

Most fet drivers are "afraid" that you'll drive the FETs at a gate voltage that is insufficient to fully turn on the FET. When that happens, the FET would blow because it had voltage AND current across it so way more power than expected. So most fet drivers will have an "under voltage...
by rew
17 Feb 2018, 15:36
Forum: Related Hardware
Topic: Energy dump / overvoltage protection
Replies: 24
Views: 4522

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: 364

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: 45
Views: 7517

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: 1532

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: 364

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: 288

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: 1532

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...

Go to advanced search