I want to use the 25d dc motor rated as 12v, with 24v power supply and Drv8871 driver
(https://www.pololu.com/product/3227/specs)
Possible? Or need to make any adjustments?
Hello.
You can do that as long as you limit the maximum duty cycle to 50% to keep the average voltage from exceeding around 12V. That motor driver might work, but it seems underpowered, which could cause you problems. My recommendation would be to use the TB9051FTG carrier instead.
- Patrick
Thank you for the answer.
I read the tb9051 specs, looks great except the issue my logic vdd is 3.3v, what are the main pros against the Drv8871?
About applying 24v with 50% d.c, will it be any different for your opinion then applying 12v with 100% d.c (from performance perspective)?
You can use 3.3V logic signals with the TB9051FTG, but it does require a 5V logic supply voltage applied to VCC, so if you do not have any source for 5V available in your system, you might consider our MC33926 carrier instead.
The DRV8871 can handle peak currents of 3.6A, but its on resistance is higher than the TB9051FTG or the MC33926 drivers, so I do not expect it to be able to handle as high a continuous current (although that will also depend a lot on the particular board you are using). You could be okay using the DRV8871 if you can avoid stalling it or heavily loading it for long periods of time, but the boards I recommended will probably give you better safety margins for operation.
Applying 24V with 50% duty cycle will generally have the same effect on a DC motor as applying 12V with 100% duty cycle (as long as the PWM frequency is high enough; a few kHz is usually fine as a minimum).
- Patrick