The diodes on each end must be protected since the newer color TV flybacks typically have 4 fast HV diodes in them, some more some less. They are arranged between separated windings to prevent arcing inside the flyback itself. Not just one diode as is often assumed. The early TV sets only had one thermionic diode tube for CRT HV system. Since the use of solid state diodes, most flybacks have at least 4 and as many as 8 or more in them. However, on the ground and hot sides, the last diodes have to handle a lot of power when in a chain like this. Keeping this circuit from overloading or damaging those diodes is possible but you don't want to overdrive them with too much current. Flyback failure can happen very quickly and without warning. Once a flyback fails--there is no fixing it. This can be from internal arcing, melted windings or diode failure. Under some conditions a DC flyback can even change to AC--usually if it's over powered without a load. This is rare however, I have only seen it happen once. Many people want to remove the diodes to get an AC output, this is practically impossible since these modern DC flybacks are made of very tough materials and cannot simply be melted away or cut apart. Even very strong acids are ineffective. Best if you want an AC flyback, buy one or wind one yourself. There is a video on my YouTube channel "mostlymacros" describing this. I wound up to 20kv high current AC flybacks myself. There are some companies still making them as well for various devices and they are easy to order last I checked.. Also a good resonant frequency must be found to get peak voltages out of this kind of system. This can be done with a PWM, a 555 timer will also work fine. I have many more pics will post later (a lot of disks to burn!). I also have other projects not yet posted, including an ion drive working model. Be sure to see my latest project below, the VTTC1000.
Mostly Macros™ From Spiders to Electronics and physics I started this site to show the world my passion for photography/science despite having serious life challenges. It is my hope to teach as well as to inspire others with life challenges to achieve goals.
Wednesday, October 22, 2014
The Quad Flyback Driver --200KV from color TV flybacks!
The diodes on each end must be protected since the newer color TV flybacks typically have 4 fast HV diodes in them, some more some less. They are arranged between separated windings to prevent arcing inside the flyback itself. Not just one diode as is often assumed. The early TV sets only had one thermionic diode tube for CRT HV system. Since the use of solid state diodes, most flybacks have at least 4 and as many as 8 or more in them. However, on the ground and hot sides, the last diodes have to handle a lot of power when in a chain like this. Keeping this circuit from overloading or damaging those diodes is possible but you don't want to overdrive them with too much current. Flyback failure can happen very quickly and without warning. Once a flyback fails--there is no fixing it. This can be from internal arcing, melted windings or diode failure. Under some conditions a DC flyback can even change to AC--usually if it's over powered without a load. This is rare however, I have only seen it happen once. Many people want to remove the diodes to get an AC output, this is practically impossible since these modern DC flybacks are made of very tough materials and cannot simply be melted away or cut apart. Even very strong acids are ineffective. Best if you want an AC flyback, buy one or wind one yourself. There is a video on my YouTube channel "mostlymacros" describing this. I wound up to 20kv high current AC flybacks myself. There are some companies still making them as well for various devices and they are easy to order last I checked.. Also a good resonant frequency must be found to get peak voltages out of this kind of system. This can be done with a PWM, a 555 timer will also work fine. I have many more pics will post later (a lot of disks to burn!). I also have other projects not yet posted, including an ion drive working model. Be sure to see my latest project below, the VTTC1000.
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