Piezo crystal from spark ignitor to capacitor to spark gap?
So, I'm making a little combustion engine, it's a passion project and I've always wanted to make one, specifically using piezoelectric ignition, yup those little things in barbecue igniters. Now I've done the math and it can work and believe me many model engines use a piezo ignition system, they're just not common is all. You might be wondering why I'm not on an engine building forum and trust me I am but those guys aren't so great when your asking amateur level electronic questions. Now I've ran into one specific issue, the piezo crystals have to be struck by a spring, because striking them with something directly connected to the drive train would lead to say... 'rapid disassembly' of the crystals.
Now the problem with using springs is that although they are pretty quick, they just aren't quick enough, meaning that if your at high rpms, they're a little too slow. Now I admit it's only an issue at formula one level rpms but I am ambitious and I don't want unnecessary bottlenecks if I don't need them. So you can add in a predetermined delay but that leads to more issues when your considering that the rpm is dynamic. Bottom line relying on a spring is a bad choice. So I want to keep my piezo crystal ignition system, basically because I think it's cool, that's pretty much it. If I'm going to do that I need a middleman of sorts, that can instantly discharge a spark when called upon. So I was thinking of using the drivetrain to trigger a spring which will strike a crystal, which will charge a capacitor, then when the drive train triggers another switch the capacitor will discharge and create a spark exactly when I need it.
So, guys going to be honest, I know pretty much nothing about electronics, well I know the basics but this stuff is pretty much still magic to me and I am in no way capable of designing a circuit like this myself, fine with the mechanical stuff but really need someone to tell me what components to buy and how to connect them up in a circuit. If it helps I think a piezo crystal releases about 12,000 volts when struck.
So more concisely...
I need someone to design a circuit for me that consists of a capacitor that can be charged by a piezo crystal ( the same one's in those cheap barbecue lighters) that when triggered by a switch (a normal trigger switch will do but if you folks think I need a mosfet for that super fast on and off stuff, that's fine by me I honestly have no idea.) will create a spark over a spark gap ( No need to think of a actual spark plug just two wires separated by a few 'mm' will do. ) that doesn't destroy the circuit in the process. Now I'm pretty sure Piezo's create AC current so maybe I need a diode for DC shenanigans . That's your guys call. Please try to explain what your doing and just tell me what to buy. That would be fantastic! Else I'll just be overcharged by some pcb designer on Fiver.
Thank you!
- David