I wondered if 'magic sine waves' as promoted by Don Lancaster @ http://tinaja.com/magsn01.asp might be an easier approach. They are supposed to be microprocessor friendly and suitable for inverters.
Here's a brief description taken from Don's psge: "Magic sinewaves" are repeating long sequences of ones and zeros. They can get created from ordinary but extremely carefully chosen digitally switched pulses.
Digital sinewaves with precisely controlled amplitudes and amazingly low distortions. Compared to traditional PWM, magic sinewaves can offer far higher efficiencies and lower distortions. With circuitry that is elegantly simple and microcontroller friendly.[ Parent ]
not a true sine-wave inverter
RobD[ Parent ]
Cya, Chris[ Parent ]
on another note you could start and make a dc-dc converter first say 24vin 170v out.. pwm controlled, take a recitfied 170v out and run it to an H-bridge, controll the H bridge with a 10-25khz pwm signal modulated by a 60hz stable sine wave, then filter the output of the H-bridge to remove the 10-25khz pwm frequency and your left with a nice sine wave output at a high efficiency.
I have been trying to come up with a good dc-dc converter information to try and design a 24v-170v converter (that in itself is easy, just getting it to put out 10-20A is the hard part) so if anyone could help in this arena I may have schematics available by the end of the year :)[ Parent ]
This is not new at all but have any of you considered just driving an induction motor at its generating speed [with caps added] by using a dc motor from your batteries perhaps with some form of speed regulation?
The output from an induction motor would be the purest of sinewaves.
Just another way although mechanical it would work.
Cheers.
TomW
Light Travels Faster Than Sound, Which Is Why Some People Appear Bright Until You Hear Them Speak.
but the concern would be how efficient would (say a 5hp) dc motor be? plus the current draw of the motor unloaded to spin the induction motor with relatively little load? using 250W of power to spin a motor to run a 50W ac load might not be reasonable (wattages just guestimated as I have no source to back it up)[ Parent ]
It's not bad ! boB [ Parent ]
I could also make them on 1k modules
Did you ever get this up and running?
I found your post after having the same idea. Everything should be as simple as possible. not simpler.[ Parent ]
using toroids for the stepup supply , 25khz switching freq
my first electronic Job was for ELPAC , electronic switching power supplies
I will monitor the current though each module with a current sense [ Parent ]
