Thanks.
The inverter output frquency is 60Hz. i intend to step up to say 6KHz .
now the input to the mains transformer of amplifier will be 220V , 6KHZ, and high inductance of input transformer may provide lesser losses, better regulation , less transofrmer hating up and i assume better efficiency than running the amplifier on 60Hz mains ????
The inverter output frquency is 60Hz. i intend to step up to say 6KHz .
now the input to the mains transformer of amplifier will be 220V , 6KHZ, and high inductance of input transformer may provide lesser losses, better regulation , less transofrmer hating up and i assume better efficiency than running the amplifier on 60Hz mains ????
The eddy current losses in the trafo will go insane, causing it to heat up more. And the regulation will be 100X worse due to the leakage inductance, not 100X better. Impedance increases with frequency.
If you want some compromise by increasing the frequency, try something like 200-400 Hz. Most 60 Hz trafos will do "ok" up a little higher but 6k is asking for trouble.
If you want some compromise by increasing the frequency, try something like 200-400 Hz. Most 60 Hz trafos will do "ok" up a little higher but 6k is asking for trouble.
400 Hz is too high with square wave, but should be ok for sine. For square wave, keep it closer to 60 Hz. Maybe 100 would be ok - the 3rd harmonic would be under the 400 Hz commonly used aircraft power. Use a (symmetrical) 25% duty cycle at 300V peak for 220V RMS. Building an inverter like this, however, is not necessarily a trivial task. It sounds easy enough but audio gear is not like a flourescent light, or even an A/C motor. You may find it working quite well at light or continuous load, but with a varying load like an audio amp you can run into stability problems. Or blow out all your hexfets the very first time you try to charge the reservoir caps.
If the amp's PSRR sucks at some of the high order harmonics (say, 1 KHz) you can end up with an annoying buzz or squeal that you can't get rid of.
If the amp's PSRR sucks at some of the high order harmonics (say, 1 KHz) you can end up with an annoying buzz or squeal that you can't get rid of.
If you're going to that much trouble it would make sense to completely remove the Yamaha transformer and modify the inverter to put out the proper Voltage for the Yamaha directly. What's the point of a transformer feeding a transformer?
G²
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