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

Unless you are driving a motor, why do you need 400Hz 3phase?  Many control boards simply put the input AC power thru a rectifier/cap/regulator for ripple free DC for the logic circuits.  Once, for a home security system control box which wanted 13.8 volts AC wall wart ($30.00 plus),  I connected a $5 laptop switching power supply that is putting out 2 amps of 15 V dc.  It worked out fine.  I am thinking that your aircraft control module MAY work just fine with judiciously applied DC voltage.   I hope I have made myself understandable here.  If not, maybe MK can expound upon it.

Update: To take my Evil Genius theory to the next step, I will say to just connect 120 Vac 60 Hz on two input legs ONLY and the bridge will rectify it and power the load with no probem.  If you want to play it safe (and you should), get a Variac variable transformer and bring the power up slow from Zero Volts.

Otherwise, let's build a Tesla Museum 3-phase power supply starting with the theory and HW on the lower part of this web page: http://www.allaboutcircuits.com/vol_4/chpt_12/6.html

its for driving aircraft stuff

enjoy

"If you're unable to find a 400 Hz inverter on eBay, you can build one yourself pretty easily with an oscillator circuit (either through a 555 or a logic circuit) and a switching circuit (triac or power transistor) and a big LC filter (if needed).  A transformer is then used to make line voltage AC from battery voltage AC, this can be a pretty standard 110V-12V power supply transformer wired the wrong way round (with the 12V side as input). Also really depends on your power requirements. If you're going to start a jet from it you're gonna need a GPU."    Source  

Sounds pretty easy except for the 3 phase aspect.  I would use some N-channel JFETs for their high current abilities.  So, is this why 555 timers have such a high voltage range?  hmm. 

MK:  Are we talking 3 PWM signals with 50% duty cycles separated by 120 degrees?  From what I have read of PIC timers and PWM, that sounds doable.  So, how is it done?

Update:  Question 30 over at http://www.allaboutcircuits.com/worksheets/supply3.html  shows how to achieve DC to AC with a center tap transformer.  And there is the business about choosing between the Delta or Wye configurations.

dose not look like a good solution that might work for single phase and only 400hz if you are going to use an audio transformer,,

I thought about that already but the output might change under load (bad thing)

I am thinking about using an ardunio with 3 pwm outputs to give me the 3phase @ 400 Hz

but that's a very small output for me..

no where near 115vac and 5amps

Cristina, you could use a kit like this to get the basic control but boost up the output drive to reach the voltage you want. However it may be best to learn with this kit and develop your high volts skills as a second step.

Three Phase BLDC Motor Kit with DRV8312 and Piccolo MCU - DRV8312-C2-KIT - TI Tool Folder

A more complete kit would be:

DM300021 - MICROCHIP - POWER MODULE, DSPICDEM, MC1H, MOTOR | Farnell element14

Peter

Cristina, you could use a kit like this to get the basic control but boost up the output drive to reach the voltage you want. However it may be best to learn with this kit and develop your high volts skills as a second step.

Three Phase BLDC Motor Kit with DRV8312 and Piccolo MCU - DRV8312-C2-KIT - TI Tool Folder

A more complete kit would be:

DM300021 - MICROCHIP - POWER MODULE, DSPICDEM, MC1H, MOTOR | Farnell element14

Peter

peterjcs23 They are way to expensive..