| ROYER DRIVER SCHEMA |
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| rectifyer bridge: 800 - 1000 V @ 25 - 35 A C1 : 10 uF @ 400 V MKP non polarised R1, R2 : 820 ohms @ 5 watts L : 300 uH @ 5 A coil on a iron powder toroid D1, D2 : MUR 1100 E or BYV 26 E D3, D4 : Zener diodes 12 V @ 1 watt D5, D6 : ultrafast diodes RHRP 15120 (1200 V @ 15 A). IGBTs : BUP 314 on a heatsink (the IGBTs are just barely warm for long runs at full wave input, use small heatsinks) R3, R4 : 10 kohms @ 1/2 watt C2 : 6 - 10 uF @ 600-1000 V ( you have to experiment a little to choose the best value addapted for your flyback). The driver will work with any cap you use, even with a 100 nF one, but the spark will be weaker. The flyback primary is wound 4 + 4 turns with insulated heavy wire. The two sections of the primary L1a and L1b have to wires wound in the same direction, one wire of L1a, alternating with one wire of L1b, insulated from the flyback core. To increase the load and decrease the heating of the core 8+8 turns or 10+10 turns would be better. To prevent the breakdown to the core it is better to ground the inner end of the secondary. |
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