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Thanks for the heads up on that. We haven't heard from Spokane1 in a while, hope he chimes in.
I guess it will be time to put something together on the bench soon, with the inclusion of the biasing magnets, but I'm really not up for that yet.
I find it interesting that Graham Gunderson has not a comment (not a peep) on the excellent work being done by yourself and Spokane1. This work is all being done in the open, not on a private thread. There are almost 6000 reads of this thread...who are all those people that don't comment? Granted that you need to be signed in to comment and AFAIK he is not a member, but the work is available to be seen by the public without signing in. I wonder if Spokane1 could urge him to become a member here, or maybe the "fine print" in his contract with A&P prevent him from doing so.
Regards, ION
Dear ION, Thanks for the concern but I live in the country with no Internet service on the week ends, so I go off line two days out of seven. Besides we just had a wild fire sweep through the area. The fire got within in two houses of my home. All of our cars were loaded and in the process of evacuation when the wind direction changed. My wife went to stay with her daughter across town while I spent the rest of the evening watching water-bomber planes dropping red fire suppressant clay on the flames. In the morning it looked more homes had survived than I thought. I understand at least three houses were lost, perhaps few more. It took the fire fighting services about 2.5 hours to mobilize. Once they did we had 10 engines and one tanker scattered around the neighborhood. Certainly a stressful order for the evening. But life goes on. This weekends work showed a little promise. I was able to get the junk box mockup circuit to lock into the proper timing sequence to display the discontinuous sine wave. I just have the primary circuit operational. This evening I shall add the synchronous diode circuit and start to get a look at the backend operation. For what its worth this circuit shows: 1. This circuit will function at 12 VDC (using the single switch approach) 2. Operation can take place as low as 3.2 kHz 3. A classical laminated iron core will support the novel oscillation pattern. None of this means that we are in the OU window of operation, but it is nice to see some hardware implementation of the circuit under discussion. Using the component parameters I have in the actual circuit the simulation shows that I might be able to harvest up 6.5 Watts at a COP of .863. I'm sure the real world performance will be far less than this. The advantage of the 12 V approach is that all the excitation energy comes from one source. All the gate losses, skew losses, and magnetic probe interference issues can be evaluated. If this circuit can perform as a self runner then this is the direction to go. The simulation also shows that the circuit performance improves if I were to use a smaller charging inductance choke. The junk box device (from a salvaged X-Ray transformer) has a 1 KHz inductance of 11.5 mH. The simulation shows that I need a 2 mH unit there. Grahams circuit apparently used a .0324 mH custom device. If any one is interested in a schematic for this temporary evaluation circuit let me know. I'm sure there will be several variations employed as the circuit technique improves. Spokane1
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