Sparking

Today we tried out the coil and rudimentary ignitor on the test board. With a frequency generator we were able to successfully generate a spark across our large gapped plug. Unfortunately when i decided to increase the frequency the ballast resistors in series with the transistors overheated and burnt out. Now we at least know the coil and spark plug work. A new ignitor needs to be made with a better electronic switch. Currently two TIP120s in parallel are used with ballast resistors to prevent current favouring one transistor over the other, which is definitely not ideal. A design featuring an IGBT or similar will eliminate the second transistor and ballast resistor and be able to handle the EMF spikes much better.