15-02-2014, 09:52 AM
Thanks to all for the positive replies.
David, the ripple was only one of the problems that beset me. Worse was the RF interference the thing generates but as I described in the text, I overcame this by fitting capacitors across two of the diodes in the bridge. This was sheer guesswork, poking and prodding without much aim or idea. Fortunately I got there.
Joe, I think you sell yourself short. I'm sure you would have got there in probably much the same way (or likely quicker) than I did. As for the multivibrator output being square, it sure ain't in this circuit because of the inductive effects of the transformer. No doubt lots of ringing going on, hence the RF interference I mentioned above. By the way the device doesn't cause interference to other radios or TVs, even when adjacent to them, so those caps across the diodes appear to be doing a good job.
Refugee, have you had a look at the circuit, and is your sine wave inverter somewhat similar? The idea of a 'backwards' transformer certainly works well in the power supply, so perhaps its worth a bit of experimenting.
Thanks again to everyone for the interest and I should add that the moral support I received from Col (Retired) was instrumental in keeping me focused during the development of the circuit, despite the numerous blind alleys.
Tony
David, the ripple was only one of the problems that beset me. Worse was the RF interference the thing generates but as I described in the text, I overcame this by fitting capacitors across two of the diodes in the bridge. This was sheer guesswork, poking and prodding without much aim or idea. Fortunately I got there.
Joe, I think you sell yourself short. I'm sure you would have got there in probably much the same way (or likely quicker) than I did. As for the multivibrator output being square, it sure ain't in this circuit because of the inductive effects of the transformer. No doubt lots of ringing going on, hence the RF interference I mentioned above. By the way the device doesn't cause interference to other radios or TVs, even when adjacent to them, so those caps across the diodes appear to be doing a good job.
Refugee, have you had a look at the circuit, and is your sine wave inverter somewhat similar? The idea of a 'backwards' transformer certainly works well in the power supply, so perhaps its worth a bit of experimenting.
Thanks again to everyone for the interest and I should add that the moral support I received from Col (Retired) was instrumental in keeping me focused during the development of the circuit, despite the numerous blind alleys.
Tony
