i checked out a couple YouTube videos of people measuring real volt-ampere usage for SOX lamps, and found that the average 18W SOX lamp and ballast combo pulls approximately 135 to 140VA with a power factor of around 0.84. since it's totally unknown how good the power factor is on the Glow Object ballasts, i ordered a 300VA step-up transformer off Digi-Key yesterday, which will give me some headroom. this is the one: Signal Transformer 130-OF on Digi-Key
i will definitely report back with success/failure and measurements once i have a chance to test everything out in the coming days.
That is ridiculous. Like many people said before, do not trust the BS posted on Youtube as a source of your information, period!!
18W single choke circuit will consume 0.35A, that is just 80.5VA at 230V. OK, if you use a starter, the short circuit current will be in ~0.45A range just briefly, ~110VA, if PF uncompensated. Adding a compensating capacitor will drop VAs considerably. Let's say you are using a crappy choke with high losses of ~12W, so system power is around 30W. VA consumed at 230V PF 0.84 will be just 36VA!
Well, if we are assuming the person on Youtube uses an electronic ballast, things will be a little different, phase shift for line current will be near zero, but poor PF is instead related to a non-sinewave current consumption. Yet if we do the math, system active power consumption is 140VA*0.84PF = ~118W. If 18W is going to the lamp, where the other 100W is dissipated then? Sure the measurements were just done incorrectly...
Having said that, it is always good to have an extra power on your transformer, but at some point you just start to waste your money....