I need help designing a 400hz 115vac 3phase power supply -- Help

or, if you wanted something very simple, you've been suggesting an Arduino solution, you could derive a 3 phase logic signal with 3 logic pins and apply them to a  high voltage opamp on each phase via AC coupling and a bit of filtering. (The supply would have to provide current limit.)

Once you got this working you could boost the voltage too on the output stage.

or, if you wanted something very simple, you've been suggesting an Arduino solution, you could derive a 3 phase logic signal with 3 logic pins and apply them to a  high voltage opamp on each phase via AC coupling and a bit of filtering. (The supply would have to provide current limit.)

Once you got this working you could boost the voltage too on the output stage.

Hi.

Like so many before me I am try to build 3 phase 115v, 400Hz supply to drive an ex-aircaft gyroscope (or two).

My starting point is this ready made module

http://www.bldcmotor-driver.com/sale-11361290-110v-220v-ac-input-stepper-motor-driver-board-high-voltage-motor-control-board.html

which comprises a JY02A Sensorless brushless DC motor control IC

https://docplayer.net/146908738-Jy02a-sensorless-brushless-dc-motor-control-ic.html

and a JY213 Motor Driver MOSFET / IGBT Driver High Speed 3 - Phase Half - Bridge

http://www.bldcmotor-driver.com/sale-11344385-jy213h-bldc-motor-driver-mosfet-igbt-driver-high-speed-3-phase-half-bridge.html

To give these old gyros the easiest possible life I would like the drive waveforms to be as close to sinusoidal as is realisticaly possible so I am envisgaing incorporating 400 Hz L/C low pass filters between the output of the drivers and the gyro windings.

I have looked at various LC filter design tools such as

PI Filter      http://www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm

Chebyshef  https://rf-tools.com/lc-filter/

and understandably all of these design tools require a source and load impedances to be specified.

In my application the source impedance will hopefully be very low, and I have no idea what the gyro winding impedance will be when rotating.

Please can somebody suggest the best way forward, or point me in the direction of some helpful documentation?

Many thanks

Alan K. 

Hi Alan,

I think it's not required, an example is BLDC motors themselves, they are expensive but do not get damaged by electronic switching of voltage across the windings. Same with hobby CNC that uses stepper motors. PWM'ing of motors is very common too, although that's at a higher frequency. The current will change linearly through the coil windings due to their inductance, and this will self-smooth. If it doesn't, you can add an extra inductance in series with the winding.

Hi Shabaz.  Thank you for your thoughts and comments, and taking the trouble to respond.

As you say, I can add an extra inductance in series with the winding.

What I would like to know is how to calculate the optimum value for the inductance, and whether it would also be beneficial to add a capacitor as well?

Thanks again

Alan K.