ZVS Flyback Driver Nice sparks!
David, Mon Mar 12 2007, 10:46AMFirst of all, nice to meet here, I have been trying to register for moths, but it was disabled and the mails wont do anything. My name is David, I'm from spain and 20 years old, this year will be 21 hehe.
I made an electronics studies, but when i made some sparks I got engahed by de HV. I burned lot of transistors, especially those 2n3055s wich are the worst i´ve seen for flyback. Two weeks ago I decided to make this circuit, I was really impresed about its power.
Im using the improved version of the zvs circuit from Vladimiro Mazilli. Dunno the power, I think it will be over 350 W. now the driver is dead, as it sometimes it doesn't oscillate, and I was using a rewinded MOT so lot of current passed trought the IGBTs and they exploded (no oscillation = total shortcircuit). Using 40V that dropped to 34V with the 15cm arc. It ignites at 5 cm, but the current is so high that the arc can be distanced up to 15 cm. Flyback needs to be inmersed in oil, otherwise it arcs with everything it finds: table, primary, even the hv cable isn't enought to insolate so high voltage, I have to use a 20 cm plastic thing to keep sure that it wont hit me hehe.
15 cm arc! panic! haha.
41 secs arc video, just 7cm.It was the first time i tried the rewinded mot and the circuit wasn't well optimized. Without spacers and a few turns more on the MOT it got lots of more power.
That big 50hz noise wasn't the arc itself, was the MOT wich secondary was bad assembled and it was vibrating making a lot of noise. All that has been solved, so nexts videos I hope will be better sounded.
Frequency was over 25 KHz, great for my ears, I was fed up with the 2n3055s oscillator always running over 16KHz, disturbing everyone near it.
Now just the cat seems to be angry when i connect it haha
Sorry for the bad quality, I just have my mobile phone for making videos and photos...
]1173698123_552_FT21961_mov01034.avi[/ file]
Re: ZVS Flyback Driver Nice sparks!
Myke, Mon Mar 12 2007, 01:23PM
Nice
. Could we please see a pic of the driver and the setup?
Myke, Mon Mar 12 2007, 01:23PM
Nice
. Could we please see a pic of the driver and the setup?Re: ZVS Flyback Driver Nice sparks!
ShawnLG, Mon Mar 12 2007, 04:07PM
Awesome. Where are you hiding that MOT?
ShawnLG, Mon Mar 12 2007, 04:07PM
Awesome. Where are you hiding that MOT?
Re: ZVS Flyback Driver Nice sparks!
Dr. Dark Current, Mon Mar 12 2007, 05:45PM
That's really nice. You must have a tough flyback here because in my experience the internal diodes in the flyback usually toast in seconds with that kind of power.
Dr. Dark Current, Mon Mar 12 2007, 05:45PM
That's really nice. You must have a tough flyback here because in my experience the internal diodes in the flyback usually toast in seconds with that kind of power.
Re: ZVS Flyback Driver Nice sparks!
Electroholic, Mon Mar 12 2007, 08:07PM
i see a ferrite transformer in the bowl of Si oil.
solid state MOT?
Electroholic, Mon Mar 12 2007, 08:07PM
i see a ferrite transformer in the bowl of Si oil.
solid state MOT?
Re: ZVS Flyback Driver Nice sparks!
uzzors2k, Mon Mar 12 2007, 08:42PM
Those are pretty powerful arcs, what kind of transformer are you using? I've got a short-circuit protected MOT power supply, 50V, so I'll have to do some more ZVS experiments soon.
uzzors2k, Mon Mar 12 2007, 08:42PM
Those are pretty powerful arcs, what kind of transformer are you using? I've got a short-circuit protected MOT power supply, 50V, so I'll have to do some more ZVS experiments soon.
Re: ZVS Flyback Driver Nice sparks!
David, Tue Mar 13 2007, 05:20PM
Haha none MOT here for making sparks.
Dunno why the flyback survives... When i tried the first time the power wasn't so high so it was strange that it arced itself to the ferrite or the primary, but when i tried with the MOT, thanks God I was using that plastic thing to move the HV cable, few seconds of a big capacitive corona discharge between the the plastic base and the metal table, and the plastic heated up, arcing to the metal table.I was at a friend's house, my table its wood, but still burned every where by accidental arcs. The plastic was 0,5cm width, seems to be PVC
I was really impresed too, used to make 3-4cm low power arcs, when i gave power to that...
When there's no arc, lost of corona is discharged in air, like a small sstc.
Here's my setup configuration:
- MOT rewinded to give 40V, with 4mm (i think, maybe 3mm)cooper wire for providing almost 50A without overheating
- "Brick" diodes; 120A 600V 80nS ultrafast rectifiers, can power almost anything ;P
- Filtered with three capacitors with a total of 11,300µF at 50V
This is the circuit
Some setup pics...
I mounted the circuit quickly and bad,just for make it look like it is normally, as I had dismounted it, to mount it again when i receive new IGBTs...
Rewinded MOT..
brick diodes
other angle, brick diodes again
caps..
driver, with screwed igbts still mounted xD
another angle of the driver
flyback, everything screwed up ;P capacitors disconected by one side, the orange wire is the anode of the flyback, i take it to make arcs far of the primary for insurance hahaha
another pic of the flyback
and the lastone..
Also had tried to put a secondary self-made with less turns to give over 1-2KV, arc jumps at little distance but it can be distanced more than 1 cm, burning the electrodes quickly, even 4mm diameter steel electrodes burned up, maybe i can use this to make some welding thing hehe. No pics yet, i'll make someones when i get new igbts. Great arc-spark-emitting effect, dunno how to explain it in a good way in english hehe :P
David, Tue Mar 13 2007, 05:20PM
Haha none MOT here for making sparks.
Dunno why the flyback survives... When i tried the first time the power wasn't so high so it was strange that it arced itself to the ferrite or the primary, but when i tried with the MOT, thanks God I was using that plastic thing to move the HV cable, few seconds of a big capacitive corona discharge between the the plastic base and the metal table, and the plastic heated up, arcing to the metal table.I was at a friend's house, my table its wood, but still burned every where by accidental arcs. The plastic was 0,5cm width, seems to be PVC
I was really impresed too, used to make 3-4cm low power arcs, when i gave power to that...
When there's no arc, lost of corona is discharged in air, like a small sstc.
Here's my setup configuration:
- MOT rewinded to give 40V, with 4mm (i think, maybe 3mm)cooper wire for providing almost 50A without overheating
- "Brick" diodes; 120A 600V 80nS ultrafast rectifiers, can power almost anything ;P
- Filtered with three capacitors with a total of 11,300µF at 50V
This is the circuit
Some setup pics...
I mounted the circuit quickly and bad,just for make it look like it is normally, as I had dismounted it, to mount it again when i receive new IGBTs...
Rewinded MOT..
brick diodes
other angle, brick diodes again
caps..
driver, with screwed igbts still mounted xD
another angle of the driver
flyback, everything screwed up ;P capacitors disconected by one side, the orange wire is the anode of the flyback, i take it to make arcs far of the primary for insurance hahaha
another pic of the flyback
and the lastone..
Also had tried to put a secondary self-made with less turns to give over 1-2KV, arc jumps at little distance but it can be distanced more than 1 cm, burning the electrodes quickly, even 4mm diameter steel electrodes burned up, maybe i can use this to make some welding thing hehe. No pics yet, i'll make someones when i get new igbts. Great arc-spark-emitting effect, dunno how to explain it in a good way in english hehe :P
Re: ZVS Flyback Driver Nice sparks!
Dr. Dark Current, Wed Mar 14 2007, 04:01PM
I have one question: since the driver produces a symmetrical waveform, how it comes to that the flyback doesn't instantly explode when drawing an arc? I'm asking because there is a HV rectifier in the flyback, so shouldn't it put dc "bias" on the secondary and instantly saturate the core?
Dr. Dark Current, Wed Mar 14 2007, 04:01PM
I have one question: since the driver produces a symmetrical waveform, how it comes to that the flyback doesn't instantly explode when drawing an arc? I'm asking because there is a HV rectifier in the flyback, so shouldn't it put dc "bias" on the secondary and instantly saturate the core?
Re: ZVS Flyback Driver Nice sparks!
Steve Ward, Wed Mar 14 2007, 04:37PM
A fair question indeed. There may be a few things keeping these types of circuits working OK. Firstly, the tank circuit is resonant with a pretty good Q, meaning that energy is left over cycle after cycle. When the output is forward biasing the diodes, the Q goes down (since energy is being extracted by the arc) but on the reverse cycle, energy is only being added. But, why should it saturate provided the V*s product for the core isnt exceeded? But you are right in thinking that this circuit would be much better suited with an AC flyback, or at least something with full-wave rectification.
Steve Ward, Wed Mar 14 2007, 04:37PM
I have one question: since the driver produces a symmetrical waveform, how it comes to that the flyback doesn't instantly explode when drawing an arc? I'm asking because there is a HV rectifier in the flyback, so shouldn't it put dc "bias" on the secondary and instantly saturate the core?
A fair question indeed. There may be a few things keeping these types of circuits working OK. Firstly, the tank circuit is resonant with a pretty good Q, meaning that energy is left over cycle after cycle. When the output is forward biasing the diodes, the Q goes down (since energy is being extracted by the arc) but on the reverse cycle, energy is only being added. But, why should it saturate provided the V*s product for the core isnt exceeded? But you are right in thinking that this circuit would be much better suited with an AC flyback, or at least something with full-wave rectification.
Re: ZVS Flyback Driver Nice sparks!
sparky, Thu Mar 15 2007, 06:42AM
Steve, have you tried linking 2 flybacks in a series arrangement using this high wattage driver?? ....might be a bit overkill - but 100 kV sounds FUN, especially at 300 watts or so!!
sparky, Thu Mar 15 2007, 06:42AM
Steve, have you tried linking 2 flybacks in a series arrangement using this high wattage driver?? ....might be a bit overkill - but 100 kV sounds FUN, especially at 300 watts or so!!
Re: ZVS Flyback Driver Nice sparks!
Steve Conner, Thu Mar 15 2007, 11:46AM
What sometimes happens in situations like these is that the core saturates a little, causing the primary to draw an unbalanced current with a DC component too, such that it cancels the DC amp-turns of the secondary and the saturation doesn't get any worse. Whoever said transformers don't pass DC?
This works in theory, and in practice on ordinary iron cored transformers running off 60Hz. But in high-frequency work, the primary DC component is drawn in short, high amplitude spikes, which usually end up blowing your drive transistors.
Of course, a flyback with a gapped core may be able to stand the DC amp-turns just fine without saturating much at all. Also, many drivers refuse to supply a DC component of primary current at all.
Oh btw, nice work David!
Steve Conner, Thu Mar 15 2007, 11:46AM
What sometimes happens in situations like these is that the core saturates a little, causing the primary to draw an unbalanced current with a DC component too, such that it cancels the DC amp-turns of the secondary and the saturation doesn't get any worse. Whoever said transformers don't pass DC?
This works in theory, and in practice on ordinary iron cored transformers running off 60Hz. But in high-frequency work, the primary DC component is drawn in short, high amplitude spikes, which usually end up blowing your drive transistors.
Of course, a flyback with a gapped core may be able to stand the DC amp-turns just fine without saturating much at all. Also, many drivers refuse to supply a DC component of primary current at all.
Oh btw, nice work David!
Re: ZVS Flyback Driver Nice sparks!
David, Thu Mar 15 2007, 12:54PM
I'll try to make plasma in a bulb when i receive new transistro, they're coming ;).
If the flyback's diode is still alive, the dc HV will not make too much plasma, just a little from the DC as it is unfiltered.
If the diode is shorted, (i think that it will be) it will make lots of plasma, as it will be AC.
But 50 KV without triplier seems to be... impossible. Think that the normal HV from a flyback uses to be over 30 KV with triplier, meaning that there's 10 KV in the secondary coil;
50KV on the secondary coil just can make me remember lots of smoke, transforming flybacks into smoke grenades . Al least that is what happended to me trying to put more than 30v in other flybacks.. secondary shorts and smoke everywhere.Also 2n3055s used to die in a few
David, Thu Mar 15 2007, 12:54PM
I'll try to make plasma in a bulb when i receive new transistro, they're coming ;).
If the flyback's diode is still alive, the dc HV will not make too much plasma, just a little from the DC as it is unfiltered.
If the diode is shorted, (i think that it will be) it will make lots of plasma, as it will be AC.
But 50 KV without triplier seems to be... impossible. Think that the normal HV from a flyback uses to be over 30 KV with triplier, meaning that there's 10 KV in the secondary coil;
50KV on the secondary coil just can make me remember lots of smoke, transforming flybacks into smoke grenades
. Al least that is what happended to me trying to put more than 30v in other flybacks.. secondary shorts and smoke everywhere.Also 2n3055s used to die in a fewRe: ZVS Flyback Driver Nice sparks!
Dr. Dark Current, Thu Mar 15 2007, 03:24PM
Dr. Dark Current, Thu Mar 15 2007, 03:24PM
David wrote ...
I'll try to make plasma in a bulb when i receive new transistro, they're coming ;).
If the flyback's diode is still alive, the dc HV will not make too much plasma, just a little from the DC as it is unfiltered.
you know the hv rectifier(s) have died when there is strong corona between the flyback and its core, and the flyback usually doesn't stand this for long and arcs over (from secondary to core). If there is no corona at all, then your flyback hv rectifier is fine (and will not make a plasma globe even if it's unfiltered).I'll try to make plasma in a bulb when i receive new transistro, they're coming ;).
If the flyback's diode is still alive, the dc HV will not make too much plasma, just a little from the DC as it is unfiltered.
Re: ZVS Flyback Driver Nice sparks!
David, Thu Mar 15 2007, 06:00PM
With DC flybacks I always could see a little plasma, like small corona, because plasma needs AC, so if DC is unfiltered it has a partial AC component.
Diode died when arced to the core? I dont think so, it was on just a few, maybe 1 or 2 seconds before i disconnected it. I have never screwed a diode making arcs in dc flyback, just when imake long time arcs and the current is high it always fryes at the end. This flyback gets hot everywhere when i make long time arcs, lets say 1 or 2 minutes. Every thing inside of it may be frying, secondary coil, diode.. I dont use the internal capacitors, as I think that something gonna explode if i do so
David, Thu Mar 15 2007, 06:00PM
With DC flybacks I always could see a little plasma, like small corona, because plasma needs AC, so if DC is unfiltered it has a partial AC component.
Diode died when arced to the core? I dont think so, it was on just a few, maybe 1 or 2 seconds before i disconnected it. I have never screwed a diode making arcs in dc flyback, just when imake long time arcs and the current is high it always fryes at the end. This flyback gets hot everywhere when i make long time arcs, lets say 1 or 2 minutes. Every thing inside of it may be frying, secondary coil, diode.. I dont use the internal capacitors, as I think that something gonna explode if i do so
Re: ZVS Flyback Driver Nice sparks!
David, Sat Mar 17 2007, 12:18PM
Finally, I recevived new IGBTs.
The HV diode must be shorted, as it makes lots of plasma.
So. I'm getting 50KV without multiplier
David, Sat Mar 17 2007, 12:18PM
Finally, I recevived new IGBTs.
The HV diode must be shorted, as it makes lots of plasma.
So. I'm getting 50KV without multiplier
Re: ZVS Flyback Driver Nice sparks!
Dr. Dark Current, Sat Mar 17 2007, 01:08PM
). My dc flyback can do 70kv and the diodes are still fine, and yes it makes lots of plasma and corona, but only when the gnd wire is brought close (~10cm) to the output.
Dr. Dark Current, Sat Mar 17 2007, 01:08PM
David wrote ...
Finally, I recevived new IGBTs.
The HV diode must be shorted, as it makes lots of plasma.
So. I'm getting 50KV without multiplier
These flybacks are not meant to be run with a multiplier (but it is possible to do if you have shorted all the diodes Finally, I recevived new IGBTs.
The HV diode must be shorted, as it makes lots of plasma.
So. I'm getting 50KV without multiplier
). My dc flyback can do 70kv and the diodes are still fine, and yes it makes lots of plasma and corona, but only when the gnd wire is brought close (~10cm) to the output.Re: ZVS Flyback Driver Nice sparks!
ragnar, Sun Mar 18 2007, 10:10PM
Unfiltered DC won't have much of a 'partial AC component' in a plasma globe -- it's only by corona discharge and leakage that you can pass current -- imagine the interface between the filament/glass on your lightbulb as if it were a capacitor. It'll charge on the first half-wave... and then it'll stay charged. If the flyback had a center-tap, then you could extract an 'ac component'
ragnar, Sun Mar 18 2007, 10:10PM
David wrote ...
With DC flybacks I always could see a little plasma, like small corona, because plasma needs AC, so if DC is unfiltered it has a partial AC component.
Diode died when arced to the core? I dont think so, it was on just a few, maybe 1 or 2 seconds before i disconnected it. I have never screwed a diode making arcs in dc flyback, just when imake long time arcs and the current is high it always fryes at the end. This flyback gets hot everywhere when i make long time arcs, lets say 1 or 2 minutes. Every thing inside of it may be frying, secondary coil, diode.. I dont use the internal capacitors, as I think that something gonna explode if i do so
With DC flybacks I always could see a little plasma, like small corona, because plasma needs AC, so if DC is unfiltered it has a partial AC component.
Diode died when arced to the core? I dont think so, it was on just a few, maybe 1 or 2 seconds before i disconnected it. I have never screwed a diode making arcs in dc flyback, just when imake long time arcs and the current is high it always fryes at the end. This flyback gets hot everywhere when i make long time arcs, lets say 1 or 2 minutes. Every thing inside of it may be frying, secondary coil, diode.. I dont use the internal capacitors, as I think that something gonna explode if i do so
Unfiltered DC won't have much of a 'partial AC component' in a plasma globe -- it's only by corona discharge and leakage that you can pass current -- imagine the interface between the filament/glass on your lightbulb as if it were a capacitor. It'll charge on the first half-wave... and then it'll stay charged. If the flyback had a center-tap, then you could extract an 'ac component'
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