Electronics > Projects, Designs, and Technical Stuff
Jet engine Ignition system Build with LT375 / TL494 / ZVS driver Lockup
Amper:
But what is the solution? I havent heard it yet. I need only 20-30W of HV but in a very small package, you can see it in the videos i posted. The box also has to house the emi filter so i dont influence the sensors.
alsetalokin4017:
You probably need a different topology then. The Royer oscillator needs symmetry and high-current design and is designed to drive a low-impedance load, like a few turns of transformer primary. And it sounds like you don't really need the power levels it can deliver.
You may want to consider using 555 or CD4093 based ignition coil driver topologies.
Amper:
Yes, though those are much to little in power. I cant fit any irnition coil in the given space. The limit is a box of 43x45x15mm for filter and power electronics excluding the ccfl transformer that is already in place.
Thinking of it the cheap ccfl driver boards allways run on some kind of oscillator very very similar to the zvs. They have to little power for my application but they show that it has to be possible to get it starting and running with almost perfect reliability using no active components besides the two fets.
langwadt:
--- Quote from: Amper on January 29, 2019, 12:18:22 am ---Yes, though those are much to little in power. I cant fit any irnition coil in the given space. The limit is a box of 43x45x15mm for filter and power electronics excluding the ccfl transformer that is already in place.
Thinking of it the cheap ccfl driver boards allways run on some kind of oscillator very very similar to the zvs. They have to little power for my application but they show that it has to be possible to get it starting and running with almost perfect reliability using no active components besides the two fets.
--- End quote ---
ir2153 ?
alsetalokin4017:
--- Quote from: Amper on January 29, 2019, 12:18:22 am ---Yes, though those are much to little in power. I cant fit any irnition coil in the given space. The limit is a box of 43x45x15mm for filter and power electronics excluding the ccfl transformer that is already in place.
--- End quote ---
Well, the output power comes from whatever you switch with the switching elements, not from the oscillator per se. In the Royer (Mazzilli) you are powering and switching from the same source. In the 555 or CD4093 oscillators, you still will be driving a switching element (a mosfet or two) and it can have as much power throughput as you can manage.
You can fit a CD4093 based oscillator in the little box. You need to heatsink your switching transistor (even in the Mazzilli) so it needs to be outside that tiny box anyway. You are using the CCFL transformer to boost up to the HV necessary for your spark ignition, is that right?
--- Quote ---Thinking of it the cheap ccfl driver boards allways run on some kind of oscillator very very similar to the zvs. They have to little power for my application but they show that it has to be possible to get it starting and running with almost perfect reliability using no active components besides the two fets.
--- End quote ---
Yes, it is possible to get the Mazzilli started with perfect reliability, if you respect its requirements! Symmetrical layout, high-current paths for the LC tank, low impedance in the output L, high current chokes, and a hard turn-on from a power supply that won't sag.
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