>Actually, is your design a boost at all? Or do you use a flyback transformer?
I suppose you mean single winding inductor boost which is a particular variation of a flyback converter, i.e. any converter where energy is stored in the inductance out of phase with the energy released to the load. The 1364 used a coupled inductor, aka transformer, whith no direct path from the input to output so that the output goes to zero when not switching. To pick up a few percentage points of efficiency on this design I went with a tapped inductor. The main reason for either of these two variations vs the single inductor has to do with the voltage stress on the main switching transistor: A single inductor flyback exposes the switching transistor to the output voltage which is traded for by an increase resistance. By using the transformer or tapped inductor, the switching transistor drain only sees a voltage during the off time of Vout x (Nprimary/Nsecondary) or Vout x (N1/N2) respectively where N1 is the turns from Vin to Vsw and N2 is the turns from Vsw to Vout. Since the output voltage is stacked on top of the input and the input voltage portion is delivered at near 100% efficiency, switchers with high input voltage benefit more from a tapped inductor than those expected to operate at low input voltages. >When you measure output power, do you just stick a meter and measure average current/voltage, or do you do something fancy to take ripple into account? The meter I use (HP34401A) has a slope converter which intrinsically averages the readings when in DC mode, however there is also an RMS AC function as well, it just wasn't part of my UI as I used a scope to watch that real time for monitoring stability. The p-p ripple target for this design at 75W load is < 1V at 200V out (<0.5%). jt -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/9391c6ad-1f97-4d58-9d00-a59bd9d3af90%40googlegroups.com?hl=en-GB. For more options, visit https://groups.google.com/groups/opt_out.
