Hello Paul, I was on holiday last week and didn't pay much attention to what passed in the reflector. So my appoligies if I tell things that have been told earlier. The "both sides conducting" issue
Hi Rik, I don't recall that having been mentioned previously in this discussion. I am sure I have read that somewhere in my studies over the past year but it obviously had not taken root as it seemed
Hello Paul, back from the pub talk now, wind the damned thing up, and see what happens! ;) Maybe the `scope is giving pessimistic info, you seem to have covered everything else. A box of shrapnel lik
Hello Paul, back from the pub talk now, wind the damned thing up, and see what happens! ;) gad! ... sounds like the liquor's talk'n ;-) WEB - "The VE7SL Radio Notebook": http://qsl.net/ve7sl/ VE7SL B
Hello Steve, In hindsight that's how I ended up married, so I should have added "at your own risk" I think ;) -- Best regards, Chris mailto:[email protected]
Hello Steve, In hindsight that's how I ended up married, so I should have added "at your own risk" I think ;) LOL Chris...you're probably not alone regarding that scenario! WEB - "The VE7SL Radio Not
Paul I just tried my earlier suggestion of doubling the value of the 'timing' capacitors to 2000 pF on the amplifier. As expected, the dead zone between the phases about doubled ... and is now signif
Jay, I agree everything points to a problem in the driver circuit. This morning I set up the scope very carefully, took pictures of the gate waveform with the 2000pf. I then removed the added cap on
Paul The outputs of the 74F74 (measured at the 74F74) should be such that one phase turns off while the other turns on ... essentially on top of each other with no dead zone. These outputs are delaye
Jay, When the package arrives I will swap out the caps and the IR2110. If that doesn't do it I will order a new 74F74 and swap out the resistors. If all of that fails I don't see anything else I can
Hello Paul, I am looking at your photo of the LPF. The specs say L1 and L3 should have 52 turns, and L2, the centre one, should have 73 turns. i was unable to get 73 turns on the toroid without windi
Hi Chris, Actually that's a bit of trickery on my part. :-) I wanted all the coils to "look" about the same. All the Delrin end plates are 1/4" thick. On the center one I wrapped the core with glass
Paul, Chris, Jay et al Just a wild thought....Jays LPF is not inside the PA box. The filter is giving a frequency dependent load on the PA. Could it be possible that some reflected impedance is exage
Hello Paul, OK, I believe you, I can recognize OCD when I see it ;) Here's a close up of my output transformer from the amp the waveforms were taken from and posted. `Tis now a bit ugly, with a few b
Yes, I agree with Alan and fail completely to see why the driver should have any effect on the ringing. It just cannot. As I keep saying, such ringing is commonplace in SMPSUs and is due to leakage
Another thought what happens if there is too big an ''underlap'' FET 1 switches off there is nowhere yet for the current to go, so a big back emf spike til the other FET switches on. Laurence KL7L co
Paul Please recheck the power wiring of the driver IC An unpowered driver produces output waveforms anyway and you will find huge ringing in the drain of the mosfets and low power output Unbelibeable
