Flyback Transformer Driver
flyback transformer driver
general description and circuit operation:
this is an efficient flyback driver for modern cylindrical rectified television flybacks. many sites doesn't provide circuits driving these transformers, they simply say that they are bad.
i don't agree. in fact i built this circuit. i spent a lot of time for finding resonant frequency (around 15khz) and duty cycle. these transformers best work at around 90% duty cycle. you may notice corona breakdown at terminals and pfffff sound (as well as the ozone smell) when adjusting the off time trimmer to near 500-300 ohms. of course it will work for other tipes of flyback as frequency and duty cycle have a large range.
frequency range can be increased using multiposition switch for other values of c3 capacitor ,for example 2 nf for 80khz-200000khz, but didn't found flybacks with so high resonant frequencies, in addition with higher values of c3 , eg 200nf, 2uf the
frequency will drop making possible the use of ignition coils, and rectified power transformers @50hz to charge high voltage electrolitic caps at 300-400v). unfortunately my ignition coil died because insulation breakdown (too long drawn arcs)...
i was able to power a small (20cm) spark gap tesla coil using these dc rectified flybacks to charge primary tank capacitor.
the operation is simple
the 555 is wired as an astable and the capacitor is charged only through the 4,7kohm trimmer (notice the diode) and discharged only through the 2.2 kohm trimmer, making the duty cycle full adjustable. the square wave is then feed in a totem pole made up of a 2n3904 and a 2n3906, which are cheap, and easy to find. the totem pole ensures the gate being charged and discharged very fast (approx 50ns i think). the irf840 is a cheap (i found it for 4euros) reliable and powerful power mosfet, it has current capability of 8 a continuous and 32a pulse, 800v drain source voltage, protecting internal zener diode. there is a snubbing network to ensure that voltage spikes are kept low (unless the insulation of the transformer start to leak) protecting both transistors and 555 ic. 100 ohm is a compromise between decay time and voltage spike.
comments and specifications:
the 100 ohm snubber must me a 5w resistor, or it will burn at long operations
the led is only for safety purposes
use a dead man switch (pushbutton) for safety
the power supply must supply at least 2-3 a if you want decent arcs (20000 kv)
dangers:
the flyback driven in this way can supply a significant current, aldough the heart fibrillation starts at 30ma
i recommend caution to avoid painful arc-burns.
the arc is a hot plasma, never operate the circuit in presence of flammable substances.
charging high voltage capacitors is a serious life threat, so if you arent unexperienced just draw arcs and no more
this device when rectified generates static voltage that can be a little annoying.... (or fun, i sprayed with corona
a plastic pen from positive terminal and then i was able to attract little pieces of paper)
disclaimer:
i don't assume any responsibility of the damages or discruptions dove by this device, to persons or things. any irresponsable action would be a serios danger. this is high voltage threat it with respect.
煤心采取率,什么是煤心采取率
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5G技术将成为智慧城市演进的核心
5G的到来伴随着什么
瑞能半导体斩获“2021年度卓越功率半导体企业”等大奖
Flyback Transformer Driver
光点科技致力于打造专业飞行平台
电动汽车发展可能发生逆转
曝国行版Switch将于12月10日上市 售价2099人民币
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电梯五方通话有什么作用
ADI启动ADI Catalyst项目_霍尼韦尔携手东华能源打造航空燃料生产基地
凸轮控制器工作原理_凸轮控制器调整方式
测量铜密度的方法分享
稳定币的未来增长将从何而来
霍金留下的最宝贵遗产：抵制人工智能武器，警惕AI
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OLED渗透率将持续提升 面板行业将迎新一轮向上周期
2020年中国企业发明授权专利排行榜发布：华为第一
general description and circuit operation:
this is an efficient flyback driver for modern cylindrical rectified television flybacks. many sites doesn't provide circuits driving these transformers, they simply say that they are bad.
i don't agree. in fact i built this circuit. i spent a lot of time for finding resonant frequency (around 15khz) and duty cycle. these transformers best work at around 90% duty cycle. you may notice corona breakdown at terminals and pfffff sound (as well as the ozone smell) when adjusting the off time trimmer to near 500-300 ohms. of course it will work for other tipes of flyback as frequency and duty cycle have a large range.
frequency range can be increased using multiposition switch for other values of c3 capacitor ,for example 2 nf for 80khz-200000khz, but didn't found flybacks with so high resonant frequencies, in addition with higher values of c3 , eg 200nf, 2uf the
frequency will drop making possible the use of ignition coils, and rectified power transformers @50hz to charge high voltage electrolitic caps at 300-400v). unfortunately my ignition coil died because insulation breakdown (too long drawn arcs)...
i was able to power a small (20cm) spark gap tesla coil using these dc rectified flybacks to charge primary tank capacitor.
the operation is simple
the 555 is wired as an astable and the capacitor is charged only through the 4,7kohm trimmer (notice the diode) and discharged only through the 2.2 kohm trimmer, making the duty cycle full adjustable. the square wave is then feed in a totem pole made up of a 2n3904 and a 2n3906, which are cheap, and easy to find. the totem pole ensures the gate being charged and discharged very fast (approx 50ns i think). the irf840 is a cheap (i found it for 4euros) reliable and powerful power mosfet, it has current capability of 8 a continuous and 32a pulse, 800v drain source voltage, protecting internal zener diode. there is a snubbing network to ensure that voltage spikes are kept low (unless the insulation of the transformer start to leak) protecting both transistors and 555 ic. 100 ohm is a compromise between decay time and voltage spike.
comments and specifications:
the 100 ohm snubber must me a 5w resistor, or it will burn at long operations
the led is only for safety purposes
use a dead man switch (pushbutton) for safety
the power supply must supply at least 2-3 a if you want decent arcs (20000 kv)
dangers:
the flyback driven in this way can supply a significant current, aldough the heart fibrillation starts at 30ma
i recommend caution to avoid painful arc-burns.
the arc is a hot plasma, never operate the circuit in presence of flammable substances.
charging high voltage capacitors is a serious life threat, so if you arent unexperienced just draw arcs and no more
this device when rectified generates static voltage that can be a little annoying.... (or fun, i sprayed with corona
a plastic pen from positive terminal and then i was able to attract little pieces of paper)
disclaimer:
i don't assume any responsibility of the damages or discruptions dove by this device, to persons or things. any irresponsable action would be a serios danger. this is high voltage threat it with respect.
煤心采取率,什么是煤心采取率
大屏幕拼接显示系统：实现高效信息传递的策略
5G技术将成为智慧城市演进的核心
5G的到来伴随着什么
瑞能半导体斩获“2021年度卓越功率半导体企业”等大奖
Flyback Transformer Driver
光点科技致力于打造专业飞行平台
电动汽车发展可能发生逆转
曝国行版Switch将于12月10日上市 售价2099人民币
贸泽电子开售Analog Devices ADuM7704 Sigma-Delta调制器
电梯五方通话有什么作用
ADI启动ADI Catalyst项目_霍尼韦尔携手东华能源打造航空燃料生产基地
凸轮控制器工作原理_凸轮控制器调整方式
测量铜密度的方法分享
稳定币的未来增长将从何而来
霍金留下的最宝贵遗产：抵制人工智能武器，警惕AI
纯电动汽车的现有发展路线导致其频繁自燃
基于CAN总线的红绿灯动态调整系统
OLED渗透率将持续提升 面板行业将迎新一轮向上周期
2020年中国企业发明授权专利排行榜发布：华为第一