Concerning the dual tl494 device, as promised, i have made a few U-core transformers and was tuning the last few days. But its like ION said before, we have 5 pot meters and no idea where to aim for, so its like shooting in the dark. The present big U-core i use has secondary 30 turns and primary 22 / 11 I tried severall different MOSFETs, presently using big IRFP264's but even those can get very hot. Voltage across the leds plus resistor runs up till 40V, so needed to increase the current limiter resistor from 10 Ohm till 470 ohm now, while also putting 4 LEDs in series (3V leds). Input is 9V with current limited to about 2A from my bench PS (a 9V battery won't last very long). I have these 12V transil diodes, but they get very hot when putting one across the upper H4 = Q1 drain to ground. Not sure if i can put 2 in series to up the protection to 24V, anyone? I have a 140V varistor across the lower B4 = Q2 drain to ground Anyway, no abnormalities seen yet. Video here: https://www.youtube.com/watch?v=Ojsj_JMH1J0&feature=youtu.beRegards Itsu
« Last Edit: 2014-06-15, 00:18:28 by Itsu »
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