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by arvidb
30 Jul 2018, 23:28
Forum: General
Topic: 2000W sensored motor. Getting higher amps at low duty cycle.
Replies: 3
Views: 305

Re: 2000W sensored motor. Getting higher amps at low duty cycle.

For commutation, rotor position is calculated from sensors at low rpm and from back EMF at higher speed where back EMF is more reliable. Speed is estimated from rotor position using a phase-locked loop (pll_run() in mcpwm_foc.c). This speed value is reported in VESC Tool and also used as feedback to...
by arvidb
29 Jul 2018, 16:35
Forum: General
Topic: 2000W sensored motor. Getting higher amps at low duty cycle.
Replies: 3
Views: 305

Re: 2000W sensored motor. Getting higher amps at low duty cycle.

Do I need PID to regulate the needed amount of duty cycle to run at a certain low speed with a high toque, or is duty cycle alone enough? Yes, you need PID control. Torque is proportional to motor current, and rpm is proportional to voltage. At 0.02 duty cycle and 30 V bus voltage you have only 0.6...
by arvidb
18 Jul 2018, 19:19
Forum: Related Hardware
Topic: Battery overvoltage protection - dump load
Replies: 14
Views: 1407

Re: Battery overvoltage protection - dump load

It's not an on-off circuit; instead the power dumped is a function of the overvoltage, as shown on the diagrams. So when it comes to oscillations, it's even better than an on-off circuit with hysteresis. ;)
by arvidb
17 Jul 2018, 00:14
Forum: Related Hardware
Topic: Battery overvoltage protection - dump load
Replies: 14
Views: 1407

Re: Battery overvoltage protection - dump load

Nordle wrote:still have to read that topic

If you don't want to read all of it, you can head straight to the working schematic. Also see rew's suggestion to use a power LED as an "automatic dump load". Very convenient, if you find power leds with the right forward voltage.
by arvidb
30 May 2018, 23:57
Forum: General
Topic: Firmware for Rev4.12?
Replies: 2
Views: 280

Re: Firmware for Rev4.12?

HW4.1x and VESC6.x are hardware (pcb) revisions. 3.37, 3.38 etc are firmware versions. The firmware (any version) can be built for any hardware revision; you need to set a #define in conf_general.h, e.g. HW_VERSION_410 for HW4.10-4.12 or HW_VERSION_60 for VESC6.x. Don't flash a firmware built for an...
by arvidb
26 May 2018, 23:07
Forum: Hardware Problems
Topic: Low Voltage on 3.3V and 5V Pin
Replies: 8
Views: 714

Re: Low Voltage on 3.3V and 5V Pin

How did D5 blow up?

If the board draws 0.9 A at 18 V (>16 W!) then something should get quite hot quite fast!

The absolute maximum input voltage for the 3.3 V regulator (TC2117) is 6.5 V, so if you've subjected it to 7.5 V it might have died.

Where did you buy your DRV chips?
by arvidb
22 May 2018, 10:59
Forum: Hardware Problems
Topic: 3.3V Problems with VESC hw4.12
Replies: 4
Views: 320

Re: 3.3V Problems with VESC hw4.12

Also check the (soldering of the) other components involved in the 5 V supply: U3, L1, R17, R18, R19, C19, C21, C27 and C39 on the DRV side, and D4, C33, R21 and D5 on the other side. Did you mount D4 with correct polarity, for example?
by arvidb
20 May 2018, 11:28
Forum: Hardware Problems
Topic: 3.3V Problems with VESC hw4.12
Replies: 4
Views: 320

Re: 3.3V Problems with VESC hw4.12

With your VESC powered only by motor power, what are the voltages over C33 and C25 (the bypass caps for the 5 V and 3.3 V rails)?
by arvidb
08 May 2018, 15:59
Forum: General
Topic: DIFFERENTS CURRENTS
Replies: 3
Views: 283

Re: DIFFERENTS CURRENTS

Well, current in is the current pulled from the batteries, and current motor is the current supplied to the motor windings. They can differ since the VESC acts as a DC/DC converter: P = Uin*Iin = Umotor*Imotor. Since the motor voltage is lower than the battery voltage except when going full throttle...
by arvidb
03 May 2018, 21:28
Forum: For sale, orders, etc.
Topic: Buying HW4.12 solder paste stencils
Replies: 0
Views: 484

Buying HW4.12 solder paste stencils

Yeah, if you have solder paste stencils for HW4.12 that you don't need, I would be interested in buying a set. Thanks!

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