Uploaded March 2026 | Updated September 2026, 2 weeks ago
I basically tore apart my old build for this and remade it again entirely. While I can't see there is much visual difference in the performance or anything, the idea being that there is nothing special going on there regarding whatever swords I might have been seeing before. Just the same general topology. While the staccato interrupting might seem to make it more complicated you are actually making things quite a bit easier by focusing on just sword spark length at a reasonable burst rate. When weighing all the variables it always seemed the easiest to build and work with especially when consolidating everything down to one decent power transformer for the controls tied to the same mains input. Where I might eventually go with this one is powering it via a small step up for 240VAC ramps but I'm pretty sure I'll need to mess with the geometry a lot.
I tried several different coils on this bridge between maybe 350khz up to 500khz and the results were close enough to just pick a random one. I'm using a random 150nF 1600VDC film cap in series with the primary here. Adding this cap can introduce pk power concerns where let's say before the cap I can just run this from a 2kW pk pure sine inverter... After the cap the bridge needs mains power to push the peaks.
Naturally QCW follows from this because it takes the same concept and allows for the same arcs or better entirely from a small DC source like a lipo pack. ("Staccato" builds are not "QCW" builds as they rely on timing. "QCW" is modulating the actual power into the inverter.) So if I have a compact H bridge I'm making I want to power with ramps I might just throw a compact buck converter on the front. So the next QCW is going to be a small 247 bridge with the buck built locally to it, and sized to what I think might be reasonably close 120VAC ramps or better etc. A nice SiC switch and diode would probably work well but I'll just use another 60N65 and some 30A hyperfast diode. The driver can be an A3120 with an isolated supply, the caps can charge from some boost converter, and it would hopefully all be small enough to put in some kind of partially 3D printed hand held frame.
I basically tore apart my old build for this and remade it again entirely. While I can't see there is much visual difference in the performance or anything, the idea being that there is nothing special going on there regarding whatever swords I might have been seeing before. Just the same general topology. While the staccato interrupting might seem to make it more complicated you are actually making things quite a bit easier by focusing on just sword spark length at a reasonable burst rate. When weighing all the variables it always seemed the easiest to build and work with especially when consolidating everything down to one decent power transformer for the controls tied to the same mains input. Where I might eventually go with this one is powering it via a small step up for 240VAC ramps but I'm pretty sure I'll need to mess with the geometry a lot.
I tried several different coils on this bridge between maybe 350khz up to 500khz and the results were close enough to just pick a random one. I'm using a random 150nF 1600VDC film cap in series with the primary here. Adding this cap can introduce pk power concerns where let's say before the cap I can just run this from a 2kW pk pure sine inverter... After the cap the bridge needs mains power to push the peaks.
Naturally QCW follows from this because it takes the same concept and allows for the same arcs or better entirely from a small DC source like a lipo pack. ("Staccato" builds are not "QCW" builds as they rely on timing. "QCW" is modulating the actual power into the inverter.) So if I have a compact H bridge I'm making I want to power with ramps I might just throw a compact buck converter on the front. So the next QCW is going to be a small 247 bridge with the buck built locally to it, and sized to what I think might be reasonably close 120VAC ramps or better etc. A nice SiC switch and diode would probably work well but I'll just use another 60N65 and some 30A hyperfast diode. The driver can be an A3120 with an isolated supply, the caps can charge from some boost converter, and it would hopefully all be small enough to put in some kind of partially 3D printed hand held frame.
