stegu wrote:More exactly how much is "a little lower"? 10% or 5%, or even less?
Primary is about 310-320kHz. The secondary is 340-350kHz, with counterpoise and breakout point.
So, it's 5 to 10%.
I guess the difference is consumed by the streamers - i tuned it based on the performance, varying the shape and size of the primary, not the precise calculations and measurements.
If anything, the secondary might need to go higher - i tried adding a small cylinder as a breakout point to get crown-shaped streamers, but the performance got noticeably worse.
Even though it lowers the frequency by only 10kHz.
DJKOR wrote:On the note of running the primary at a higher frequency to match a higher resonant frequency of a secondary, is there any disadvantage to this? Like extra load on the components or more stress on the primary
I expect more load - more switching losses, less accurate ZCS, and so on. IGBTs are slow beasts, they can't switch on a whim.
So, the on times and off times are getting closer together at higher frequency, increasing the ratio between the time IGBTs spend in the lossy region and the near-lossless region.
DJKOR wrote:Also, after a good 2.5 minute song that contains a fair few notes, should the secondary be completely cool indicating things are spot on, or are there reasonable losses in the primary that will result in it being warm to the touch?
After 1 minute of operation at full power (260VAC input, 30us notes) the bridge's radiator gets to 60*C (no fan), the primary is about 45*C, the secondary stays at ambient (28*C), give or take IR thermometre's allergy to metals.