Recent content by abudabit

24 - 48 v are the normal voltages for commercially available low power hub motors, 72 v are available for some higher powered ones. Current^2 generates the heat so higher voltage lower current is better than lower voltage higher current. And voltage isn't a safety issue at 48 v. Most...

This is my first time using the 2 shunt method of sensorless field oriented control (3 phase wye). Do I place the shunts between the source and ground for 2 of the 3 phases low side mosfets? Or do I place the shunts between where the high side and lowside mosfets connect to the winding? All...

Thanks Jimbo, that makes more sense. Skogsgurra, good eye. Yes, I meant henries.

I've never used Bifilar Winding, and had a question regarding some conflicting information. This is for parallel bifilar winding where the current flows in the same direction in both wires. I've seen it said that bifilar winding 'multiplies' the inductive field. But that doesn't seem to...

I'm new to PLC's, just finished writing and simulating my first verilog. But now I'm doing logic synthesis for the first time and running into an issue. Using Precision, I can't find any devices when I go to "Setup Design". It just says "No FPGA Devices" and doesn't even show the names of any...

Thanks for the tips guys. IR2103 (high side low side driver) looks like it should work great. Can't find a regular spice model for it though. Tried using the pspice model that IR provides but it makes multisim crash. Guess I'll order them and bread board it to see if I have the layout correct.

I'm pretty new to PWM design, and I haven't seen any examples of how to drive a dual switch PWM. Every example I've seen seems to only drive a single mosfet tied to ground. No matter what I do I can't seem to get the switches working, at least in the simulator. What I want is both...

Thank you very much, that makes a lot more sense. Glad I won't have to redesign the rotor and magnets much since I'm utterly in the dark with those.

Now I'm worried about efficiency..... If I increase wire length 3.44 times, decrease current draw by only 50%, keep wire diameter the same.... does that mean it dissipates(3.44 / 2)^2 (2.96)times more heat from the current through windings? What effect does increasing the diameter of the rotor...

Don't forget inefficiencies in the controller. Take your measurements before the controller and not between the motor and controller.

Thank you very much Shamila.

I want to increase N-m/A by 3.44 times and inversely decrease RPM/V but I don't want to decrease the volume / length of the wire by so much. I will of course add more powerful permanent magnents to compensate. Do I increase the wire length 3.44 times or will there be more to it since I won't...