| SCHEMA OF THE SETUP |
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| Cfilter = 200 nF @ 1600 V polipropilene cap Cg2 = 4.4 nF @ 1600 V polipropilene cap Cg1 = 1.1 nF @ 1600 V polipropilene cap Cp = 20 - 30 nF @ 1600 V polipropilene cap; the value depends by the size of the flyback used. Rg2 = 2.7 kohms @ 3 watts Rg1 = 10 kohms @ 1 watt tube : PL500; fillament rating = 27 V @ 0.3 A the ground is my water pipe from my home. The primary of the flyback has to be re-wound. The old turns are removed (it is easily to work with the old flybacks with the cores held in place with screws). L2 will have 30 turns with magnet wire 0.5 mm diameter, in a single layer. L1 has 60-90 turns with magnet wire of the same diameter. Use insulation tape between wire layers (approximative 25 turns/ layer). I prefer to use more turns (around 90) with small flybacks (from portable TVs) and a smaller number (60 is better) for flybacks with higher section core. The primary cap (Cp) depends by the size of the flyback: small flyback (90 turns in primary)------------------Cp = 25 - 30 nF ( I used 24.6 nF) big flybacks (60 turns in primary)-------------------Cp = 20 - 25 nF ( I used 22.4 nF) You can experiment with different primary turns and different Cp values for the best results, depending the flyback you are using. The setup is fed through a variac, max 220 vac, full AC wave rectifyed, with separate power (small transformer) for the fillament of the tube. I obtained the best results for plasma globes with smaller flybacks (higher current output). The bigger flybacks give longer arcs in free air, but I supposed that they don't run at a proper power level with my setup (place for more power, especially by increasing the input voltage). |