Search found 310 matches

by pf26
08 Feb 2018, 15:50
Forum: FOC
Topic: VESC FOC for a flywheel application....
Replies: 14
Views: 3205

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

@seandepagnier: 100kERPM is not 100kRPM. For large pole pair numbers, extreme ERPM are easily achieved.
by pf26
08 Feb 2018, 15:46
Forum: General
Topic: Calculating motor heating?
Replies: 4
Views: 837

Re: Calculating motor heating?

I think your calculation is correct: Rxi² = 0.1 * 20² = 40W joule losses. As for the iron/friction losses, you can estimate them with a constant drag torque of 1-2% of the max motor torque, depending on motor quality obviously. You could also measure your motor no-load power consumption vs RPM, and ...
by pf26
14 Jan 2018, 09:52
Forum: General
Topic: Disabling all "ramping features"
Replies: 1
Views: 465

Re: Disabling all "ramping features"

Possibly you could review your chain by: Arduino DUE => CAN => VESC => Motor with Encoder (also used as Position Sensor if you implement multiturn detection in a VESC custom application) => Apparatus => extra position Sensor (if needed) => Feedback to Arduino Then you could use the VESC internal pos...
by pf26
13 Jan 2018, 16:16
Forum: Feature Requests
Topic: Out of the box support for AS5048
Replies: 9
Views: 3892

Re: Out of the box support for AS5048

I think the AS5047 support uses a software SPI, in encoder.c : The MISO ReadPad is done after the SCK SetPad, when it probably should only occur after the SCK ClearPad static void spi_transfer(uint16_t *in_buf, const uint16_t *out_buf, int length) { for (int i = 0;i < length;i++) { uint16_t send = o...
by pf26
31 Dec 2017, 10:45
Forum: Custom Applications
Topic: CAN-BUS Forwarding
Replies: 5
Views: 3051

Re: CAN-BUS Forwarding

In datatypes.h, you can see the enumaration of all communication commands, and COMM_FORWARD_CAN is the 33rd in the list, hence the constant COMM_FORWARD_CAN=33.
by pf26
29 Dec 2017, 19:19
Forum: Custom Applications
Topic: Brake at special position? is this possible ?
Replies: 1
Views: 706

Re: Brake at special position? is this possible ?

If you constantly send the same reference position, the motor will always try to move to that position. If you turn the motor axis away from this position, it will give a torque (depending on the maximum motor current you set) so as to return to this position. I think you better use rotary encoder w...
by pf26
29 Dec 2017, 09:00
Forum: Hardware Problems
Topic: VESC DRV8302 Problems MOSFET Swapping Considerations to all!
Replies: 14
Views: 4487

Re: VESC DRV8302 Problems MOSFET Swapping Considerations to all!

Unsoldering the FETs with hot air should be quite easy if you had a hot air station. I think you better leave the FETs in place and add a thick copper bar to the drain of the 3 top FETs, in order to connect them thermally with your aluminum case (it will connect these electrically too, unless you ha...
by pf26
28 Dec 2017, 17:53
Forum: Custom Applications
Topic: VESC for VR treadmill
Replies: 4
Views: 1255

Re: VESC for VR treadmill

Yes it is (possible).
You need to firstly connect each VESC to the VESC tool and set a unique CAN ID for each VESC.
Now you connect both VESCs on the same CAN bus and send specific commands to each VESC using its CAN ID parameter.
by pf26
19 Dec 2017, 18:54
Forum: General
Topic: 14S VESC ?
Replies: 97
Views: 27264

Re: 14S VESC ?

I fear 13s is already quite risky.
12s is safe provided you have good capacitors near the VESC.
@ThierryGTLTS: did you use a VESC with regen at 13s, or know someone who did that for long times ?
by pf26
16 Dec 2017, 13:36
Forum: Related Hardware
Topic: Gate resistors in MOSFET
Replies: 3
Views: 1135

Re: Gate resistors in MOSFET

When you want to control the MOSFET turn ON and OFF times, the gate resistor limit the gate currents and increase MOSFET switching times. Otherwise, the dV/dt would be higher, would generate larger RF emissions, and could be destructive (because of components and pcb parasitic inductance and capacit...

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