The most easy way at hobbyist level is a frequency generator, driving a phase shift network, driving 3 audio amplifiers. Mikeselectricstuff made it in one of his videos if I remember correctly.
I was actually thinking of that. However I am not sure if an amplifier can provide the +/-170V peak neccesary for the job, but maybe 3 transformers wired the other way around could help with that. The more I think of it the clearer it becomes. 400 Hz Generator, phase shifter, el cheapo audio amp and then 3 transformers. Should be doable with just junk parts. Maybe even with harvested avionics type transformers used the other way around since they are optimised for 400 Hz.
I built a single phase 400hz supply exactly as you described, with an audio power amp driving a transformer the wrong way round. I think I used a single transistor phase shift oscillator and a TDA2003. I did this a long time ago to power a wind direction transmitter and indicator made from 2 synchros. It would be easy enough to make a phase shift network to give 120 and 240 degrees shift, probably just an R/C network. You could compensate for the loss by adjusting the amplifier gains :)
A variometer has a direct connection to the inside of the pressure capsule, and a calibrated restriction leading to the housing- i.e the outside. So if the aircraft is climbing, the air pressure on the inside of the capsule falls faster than that on the outside, which makes it contract and moves the pointer clockwise, showing a rate of climb. if the aircraft then levels off, the pressure then equalizes via the restriction, and the needle returns to zero. The glass micropipettes are the restriction and the other larger pipe the direct connection, I am guessing. Probably one of the glass tubes is trimmed to length to calibrate the instrument. Note that the dial is calibrated in meters per second, whereas western instruments are calibrated in feet per minute. :)
I think you should build a 3 phase 24 / 110V power supply so you can run your gyro's, all you need is 3 mains transformers, and arduino and 2 Lm298 bridge modules.
Would be cool if you could power that thing up. Say by a hacked car generator or brushless motor from an old washing machine etc.
Chip Guy Vids been thinking about this too, a 400hz 3 phase supply is needed for a lot of avionics stuff. I'm sure there's a market for such a thing!
Some BLDC (brushless DC) motor circuit, i.e. a cheap chinese industrial motor control should be able to do the job.
The most easy way at hobbyist level is a frequency generator, driving a phase shift network, driving 3 audio amplifiers. Mikeselectricstuff made it in one of his videos if I remember correctly.
I was actually thinking of that. However I am not sure if an amplifier can provide the +/-170V peak neccesary for the job, but maybe 3 transformers wired the other way around could help with that. The more I think of it the clearer it becomes. 400 Hz Generator, phase shifter, el cheapo audio amp and then 3 transformers. Should be doable with just junk parts. Maybe even with harvested avionics type transformers used the other way around since they are optimised for 400 Hz.
I built a single phase 400hz supply exactly as you described, with an audio power amp driving a transformer the wrong way round. I think I used a single transistor phase shift oscillator and a TDA2003. I did this a long time ago to power a wind direction transmitter and indicator made from 2 synchros. It would be easy enough to make a phase shift network to give 120 and 240 degrees shift, probably just an R/C network. You could compensate for the loss by adjusting the amplifier gains :)
A variometer has a direct connection to the inside of the pressure capsule, and a calibrated restriction leading to the housing- i.e the outside. So if the aircraft is climbing, the air pressure on the inside of the capsule falls faster than that on the outside, which makes it contract and moves the pointer clockwise, showing a rate of climb. if the aircraft then levels off, the pressure then equalizes via the restriction, and the needle returns to zero. The glass micropipettes are the restriction and the other larger pipe the direct connection, I am guessing. Probably one of the glass tubes is trimmed to length to calibrate the instrument. Note that the dial is calibrated in meters per second, whereas western instruments are calibrated in feet per minute. :)
I think you should build a 3 phase 24 / 110V power supply so you can run your gyro's, all you need is 3 mains transformers, and arduino and 2 Lm298 bridge modules.