EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: henry85 on May 09, 2017, 01:57:58 pm
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Hello,
I'm writing as I'm designing this new dual channel controller for a robotic project. The thing is that it's my first ever project with such complexity. And I'm afraid there might be some flaw that me as beginner I wouldn't spot. Could you guys give me maybe some kind of advice on that?
Please find attached the schematic. The whole idea of the design is to be able to handle the 70 A of stall current of my two motors that I'm using with my robot. Oh and the idea is that the user will only have to give a PWM signal and a HIGH or LOW signal (for direction) from an Arduino or similar for driving the motors.
Also I've done some simulations and I see some small spikes of current of around 8 A. I'm wondering if I'm write to ignore them as they last only about 8-15 ns and the whole period of the PWM is about 50 us.
Thank you!
PS: You can check the board design here: https://1drv.ms/b/s!AljDQF12JgJdj_Ner8KKdz1oFIYWFg (https://1drv.ms/b/s!AljDQF12JgJdj_Ner8KKdz1oFIYWFg) (3D PDF)
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The board design link is useless. The document isn't empty, but it shows up as a tiny blank page.
You might consider using a processor suited to the task. An AVR has a slow ADC. You won't be able to monitor current and respond quickly enough. An STM32 has a much faster ADC, with fewer limitations. It can be set up for continuous conversion and checking limits in hardware. Plus the timer units have hardware deadtime support.
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The board design link is useless. The document isn't empty, but it shows up as a tiny blank page.
I couldn't view it either. It's probably because it's a 3d PDF which isn't supported by most 3rd party PDF viewers and requires Adobe PDF reader to work.
I can see the schematic attached to the post though. What's the point of the logic gates? Can't their functionality be incorporated into the MCU software?