which one is more dangerous ac source or dc source

[hurk27]

That's an interesting assertion. It's been a while since I have had my scope connected to the primary side of an ignition coil, but I don't recall seeing the wave ever drop below the zero line. But then, that's not what I was looking for. The book has examples of patterns that show bouncing points, bad capacitors, etc. (Yeah, points. The scope is that old) along with what a normal pattern looks like. Next time I am downstairs I'll go take a look.

Primary side of an ignition coil would be pulse DC, secondary side of ignition coil will be AC (HV side)

Same effect of a vibritrol supplying a transformer for DC input AC out<< first inverter made