Actual transformer used in this video is from an old tv, which is not exactly as per the design. Zvs zero cross voltage switching flyback transformer driver, capable of generating high voltage and frequency driven by 2 power mosfet. The higher this value is, the lower the efficiency you get, because more. L and the capacitor next to them c dont have values because its. Initial pulse is driven into primary, and once the tank capacitor is. The zvs flyback driver either using bjts or mosfets have been used in high voltage devices such as tesla coils, marx generators, ion experiments, and ccfls. Feb 03, 20 last summer i encountered some videos of the zvs driver online.
You can easily pump several hundreds of watts into the flyback transformer and the output current would be around 50ma to 200ma or even more, which is way above the lethal rate which is 10ma. I eventually changed to a 555 timer flyback driver, which for me is less powerful but more reliable. During freewheeling phase the vcc capacitor of the ic, the output stage and the additional zvs capacitor at zvs winding for introducing a forced resonant cycle see chapter 4. Aug 28, 2011 capacitor charger used for my coil gun. Changing the value of the capacitor can also affect the performance. W zvs low voltage induction heating board module flyback. A novel zerovoltageswitching zvs pulsewidthmodulated flyback dcdc converter with a simple auxiliary circuit is proposed. Download scientific diagram mazzilli zvs flyback converter circuit. You may also use the zvs flyback driver with a ferrite core and a custom made hv. The mazilli zvs driver, also known as the royer driver, is a self resonant, pushpull, free running oscillator that uses a transformer to make a high voltage.
I hope that my pictures help to educate a better way to use this flyback transformer and zvs driver for demonstrations and experiments using high voltage. The idea is to use multiple capacitors to divide up the current, so these in parallel should work. Zero voltage switching zvs is considered the panacea for all the challenges. Beware of zero voltage switching mouser electronics. The decoupling capacitor value will be calculated based on the energy.
I get longer copper pipe, now i can get up to 9 turns. My box shows the primary side voltage of the zvs driver being applied with voltage, current, power and energy consumed by the zvs driver. The values of the resistor are not fixed, and values for 150 to 300 ohms should work for the 5w resistor, and similarly 15 ohms to 35 ohms for the 1w resistor. Make sure you use a mosfet and not a bipolar junction transistor, the symbol in the datasheet should resemble the one in the schematic. D4sparks a zvs driver for flyback and other high voltage transformers. The t2 knob can be used to set a longer time interval. Zvs flyback drivers and other assorted components for sale.
Introduction the mazilli zvs flyback driver is wellknown throughout the high. The boost converters only strength as a capacitor charger is simplicity, its both inefficient and slow. The values of t1 and t2 increase from left to right. Design guide for qr flyback 7 design note dn 201 v1. Fluctuation in line and load affects the output voltage and hence the regulation of the converter. When switching element q 1 is on, current flows from v through the coil land charges the output smoothing capacitor c o, and the i o. The auxiliary circuit is configured in the presented zvspwm flyback. Now, the capacitor value we need to make this circuit work properly is 0. Capacitor calculation for buck converter ic this application note explains the calculation of external capacitor value for buck converter ic circuit.
This text has explained the basics of flyback converter switched mode power supply design and is applicable to most flyback converters. Choosing capacitor value for my tesla coil electronics. Due to renewed interist in the mazzilli driver flyback kits, i have created a pcb layout and acquired all components necessary for creating a few complete drivers either in kit or assembled form. Flyback controller driver frquency changer tesla coil driver. Below is a youtube video of the oscillator powering a flyback transformer at 12. That flyback killed my zvs driver but luckly i have a backup one. Flyback controller driver frquency changer tesla coil.
Capacitor energy calculator kaizer power electronics. Improving the standard flyback converter for high voltage applications. Detecting flyback automatically follows the flyback circuits resonance frequency. Schematic for a zero voltage switching zvs flyback driver. The zvs on the other hand was promised to be the most efficient driver around, and the videos of it only supported this. The zvs flyback driver, made popular by vladimiro mazzilli, is one of the most. It can be used for diy players to make small parts quenching, annealing and other heat treatment, heating fast, very convenient. Beware of zero voltage switching sanjay havanur, sr. This is then rectified and filtered to achieve a clean dc voltage that is fed to the zvs oscillator board. This appears to be a brilliant idea id never seen it suggested.
Flyback transformer driver using an electronic ballast. Spark gap can be widen at 3 cm when working with 55 volts but at 30 volts max length is 2cm. D4sparks is a great building block for tesla coils, jacobs ladders an co2 laser supplies. A flyback constant frequency zcszvs quasiresonant converter. Sainsmart zero voltage switching tesla coil flyback driver. Flyback converter for high voltage capacitor charging. In a standard flyback converter or in an active clamp. The energy stored in l2 is completely discharged into the boost capacitor via d2 during the. A typical choke value for a zvs driver operating near 100 khz is around 100. The zvs flyback driver, made popular by vladimiro mazzilli, is one of the most efficient and powerful flyback drivers used by high voltage hobbyists from all over the world. Q1 then behaves as an ordinary pfc switch, storing energy in the boost inductor l1. If the values are too low, they will drain current from the output unnecessarily. A zvs driver is a very simple circuit that can oscillate a large amount of power. Chellamuthu school of electrical and electronics engineering, anna university, madras 600 025, india abstract the analysis and simulation of a flyback zero current switchingzero voltage switching quasiresonant converter operating at a.
As mentioned above this driver drives the flyback in flyback mode. Initial pulse is driven into primary, and once the tank capacitor is charged, the lc inductorcapacitor. I cut my old capacitor in two pieces now i have two 10nf capcitors. I had heard of people using the mazzilli flyback driver and a rectified transformer before, so i gave it a shot myself. Determining input capacitor cin and the dc input voltage range. Flyback to replace bug zapper hv transformer page 2. I already had the zvs module, a good flyback transformer with built in hv diode, and lots of hv cables. Zvs zero voltage switching flyback driver simulation.
The mazilli driver uses mosfets and diodes to turn the mosfets on or off depending on the tanks voltage. Capacitor energy calculator to calculate capacitor charge in coulombs and capacitor energy in joule, enter the rated capacitance of the capacitor and the voltage it is charged to. The main advantages of this driver are simplicity of the circuit itself, very high efficiency and easily obtainable parts. Introduction the mazilli zvs flyback driver is wellknown throughout the high voltage community for its simplicity and ability to deliver 2050 kv at high currents for a flyback transformer. The flyback is a device that gets a lot of people really into electronics, because it is an easy way to creat high voltage, and because its super fun. I ordered the components for making a mazzilli driver. Buck converter figure 1 is the basic circuit of buck converter. Coil gun capacitor charger zvs flyback driver youtube. Is it possible to simulate a flyback transformer in ltspice. Here is a little picture of the label on the flyback. For a different frequency range you can use a 555 timer calculator or just experiment to find new capacitor and resistor values. The ucc28600 evaluation module, ucc28600evm65 w, is a 65w offline quasiresonant flyback converter providing an 18vregulated output at 3.
The zvs driver circuit is a royertype pushpull oscillator with a resonated primary that is implemented with fets. Mar 16, 2012 this single transistor flyback driver topology was created in response to achieve higher efficiency and higher output voltages from ordinary crt television flybacks diode split flybacks, for experiments such as xrays or ionic lifters, without having to make any external hv multipliers. I had derped around with single transistor flyback drivers, but it wasnt anything too serious. The current going into the diodes is limited by the 470 ohm resistors, if im correct. The step 9 page going further now includes a way to measure these illustrious voltage spikes with a regular volt meter. We tested when it works 53v power supply, current can reach 30a. So as the voltage one side of the lc circuit goes up, it pulls down the gate of the mosfet on the opposite side, through the diode d3 and d4. I use a flyback with a zvs driver and a modified m. The schematic has been updated to include basic transistor protection in the form of a capacitor and diode. Mazzilli flyback driver boards are donenote i am sold out of the type 2 boards, and running low in type 1 boards and irfp250 mosfets. The above indicates that, ideally, type 26 material can be used as a zvs driver at a power level of approximately 200 watts.
Zvspwm flyback converter with a simple auxiliary circuit. An alternative is to use a few lead acid batteries to power the flyback. You may also use the zvs flyback driver with a ferrite core and a custom made hv secondary, see this article. Elsevier microelectronics journal 29 1998 495504 micro onics a flyback constant frequency zcszvs quasiresonant converter p. I had heard of people using the mazzilli flyback driver and a. This type of oscillator can be used to drive the ferrite core of a flyback transformer to generate high voltage. Jan 11, 2011 schematic for a zero voltage switching zvs flyback driver. We do resonant switching is an often heard mantra in the design of power converters today. How reliable are sic fets for high voltage flyback converters. It first uses a streetlight transformer to step down the 110 volt mains current to 40 volts. How to determine component values and switch deadtimes in a flyback passive snubber circuit. Elsevier microelectronics journal 29 1998 495504 micro onics a flyback constant frequency zcs zvs quasiresonant converter p. Please refer to the datasheet for full information on the operation of the ltc38735.
The capacitor cin is also known as the dc link capacitor, depending on the input voltage and input power the rule of the thumb for choosing cin is shown. If a surplus core cannot be salvaged from an old power supply. Getting right parts and building zvs flyback correctly electrical. Zvs driver this is the zvs, or zero voltage switching, driver. I will not go higher than 36 volts because flybacks and zvs drivers dont like that much current.
Next, is the flyback itself suitable for a zvs driver. Or you can use a secondary with only a few turns of tick cooper wire, to get a current so high, that can melt thin copper wires connected across the output. Actually the value of resistance depends upon the mosfet cutoff voltage and. Thus, the ratio of the choke impedance to the primary impedance with a sustained arc is approximately 4 to 1 49. The inductor and capacitor values define the operating frequency or so a few websites. The main workhorses of this circuit are the mosfets, input power. The circuit initially was used as a high voltage driver for crt flyback coils. Chapter 5 primary zvs based flyback converter with output. After dusting off my first coil gun i thought it was about time i attempted building something more powerful. Im pretty sure the rest is pretty straight forward. This driver is very efficient since the two switching devices are driving a parallel lc tank at its resonant frequency.
The zvs flyback driver it is probably the most powerful and efficient flyback. The inductor and capacitor values define the operating frequency or so a few websites say so try and keep the same capacitance value as the original schematic as a starting point. I build this circuit almost a year ago on a vero board, but it kept blowing the thin traces due to high currents flowing. Mazzilli zvs circuits where each crt flyback was driven by single mazzilli driver. Quasiresonant flyback converter universal offline input 65. The technique of zero voltage switching is applicable to all switching topologies. Flyback to replace bug zapper hv transformer page 2 all. Improved zvs mazzilli driver, optimized for high frequency and high. So if this is your first hv project, stick to the lower power projects first. Mazilli zvs flyback driver kaizer power electronics. I do not plan to make another round of these, so whats left is what is left. In a zvs, you can use whatever values of capacitors and inductors you want. Zvs driver why does so much current need to flow through.
However, i dont see why the resistor values are so low. My main concern is winding the primary of the flyback correctly and efficiently and the capacitor bank and the inductor. There are different modes for setting the duration of the igbt on and off. Not only the zvs flyback driver is powerful, but it is very dangerous. Flyback driver circuits high voltage with a television flyback transformer. The hv from the zvs inverter and offline flyback driver has enough current to kill, so be careful. This provides the 40 volts 10 amps that powers the zvs driver board. Chapter 5 primary zvs based flyback converter with. Flyback converter for high voltage capacitor charging tony alfrey tonyalfrey at earthlink dot net a flyback converter is a type of switching power supply that may be used to generate an output voltage that is lower or higher than the starting voltage even if not. Quasiresonant flyback converter universal offline input. Switch between the input fields to automatically calculate the values. While driving the flyback transformer, the primary coil forms a special resonant circuit with a 10nf capacitor. Because i have all the components to make the resonant zvs driver but not this one.
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