ORIGINAL: azalner
Frankly, I am disappointed that we don’t see more discussion on this thread regarding circuit design and RC airplane applications. This is a RC airplane engine forum. On the other hand most guys I know don’t care about the electronics – they just want it to work.
I don't know where do you get the informatrion this is a airplane engine forum.......this is a engine conversion forum for every engine on every rc-model.
1. You introduced a new circuit for consideration. Is this based on Jean Marc Veyrat’s design?
NO, I didn't even know who Jean Marc is.
2. If so, he uses a single MOSFET to pulse the transformer. You propose using two MOSFET’s with a C.T. primary. Why? What are the advantages and disadvantages of each concept?
There are many roads to Rome, this designe can make more power out of the transformer.
3. You propose using a MOSFET instead of SCR to fire the spark plug. Why? What are the advantages and disadvantages of each concept?
A IGBT or FET can manual open or close, a scr needs negative Voltage to closed.
If you can read, there are to many troubles with the scr, so we take a other concept.
4. You talk about how critical the “flyback” (sic) transformer is. What makes it critical and how do we avoid problems when winding the transformer?
Intern resistant of the scr and wat type they use, how is the tranformer made and wat material they use, aso.
5. If we start discussing a new circuit design concept should we not open a new thread?
NO.
In the power board design concept that we are using, I noticed that the transformer coil ratio is 15t to 450t (or something close to that). This is a 1:30 ratio. Am I correct in assuming that capacitor C7 charges to .67 of full B+ voltage or (.67 x 5V) = 3.35 volts?
Thus (3.35V x 30) = 100 Volts.
If so, how are we getting 400+ volts across the secondary? What am I missing here?
Do you know how a sparkcoil funtioning.....this is also how we get 400 Volt from a flybacktransformer.