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Post by Gary Lecomte on Apr 16, 2009 5:49:59 GMT -8
Some news: I rewound feedback with 30 turns, and added small air gap to decrease windings inductance. Now it draws 0.5 amp, light output increased strongly and transistor is still only a little warm! It seems i'm on the right way. Just the Air Gap, Would have probably done OK. It reduces Saturation of the core.
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rmeyn
Full Member
My primary interests are electronics, sailing, bowling, and camping
Posts: 163
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Post by rmeyn on Apr 16, 2009 17:46:39 GMT -8
Iamazoid/Gary I was able to simulate Iamazoid's circuit using parallel, non -linear inductors. Iamazoid is correct in stating that this must be done to simulate such a transformer. Without using the K linear directive the coils will not be coupled. I've attached my simulation output with labels denoting the various voltages. This is a particularly difficult assignment, I think, for a computer simulator. LtSpice is particularly good when simulating integrated circuits and I still think it is a very powerful tool. www.knottyaldermouldings.com/Circuits/Iamazoid circuit 0409.JPG[/img] How does this compare to your actual oscilloscope output? If it is vastly different, in what way is it different? Richard
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Post by lamazoid on Apr 16, 2009 21:50:56 GMT -8
Pulses on that simulation are too short compared with my results. My scope is old one and it isn't very precise , but , it shows pulse length and period in order of tens microseconds . I have noted 2n2222 transistor , maybe it's too fast in comparison with high power transistor. Try 2SD882 , this was in original commercial device.
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Post by Gary Lecomte on Apr 17, 2009 4:17:21 GMT -8
Yes, That Frequency and Pulse Width is WAY OFF BASE.
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rmeyn
Full Member
My primary interests are electronics, sailing, bowling, and camping
Posts: 163
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Post by rmeyn on Apr 17, 2009 5:04:58 GMT -8
Yeah, I forgot to mention that the choice of transistor has a great affect on the frequency. I used the 2n2222 just because it was available. I tried an NPN power transistor earlier and the frequency was much lower. One of the big advantages, I think, to simulators is that you can easily try different devices and see how the output is changed. I'll try another transistor and post the results. Also, I try to post power consumption of the various components. I'm having fun. Richard
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