Whoops said:
I think you are overthinking this in wanting to make different Bulb Current limiters, most people only have 1
It depends very much on context.
If you have to work on a tube amp that has sat for years unused, you want to start slow, just to make sure there is no hard short, like a shorted tube or capacitor, then you can increase the bulb power to make sure the idle voltages/currents are correct and stable. Only after that you can use a bulb that's dimensioned to the (almost) full operation.
It used to be easier when there was a larger choice of incandescent bulbs.
Actually, light bulbs are far from being adequate, because of their own high intrinsic non-linearity; during the turn-on period, they don't provide much protection. A cold bulb measures less than 1/10th of its nominal resistance, which means it can let pass about 10 times its nominal power during the first 10-20ms, which is enough to make a lot of damage.
Fortunately, most of this surge is absorbed by the xfmr core for its initial magnetization, but still, until the filament is hot enough, there is not so much protection.
A much better protection would be achieved by using power resistors, which value does not change so much, as long as the nominal dissipation is not exceeded. The only problem is the cost and the bulkiness.
The big advantages of light bulbs are:
Cost and availabilty.
Ease of implementation, with all the hardware commonly available.
Signalling effect.
When incandescent bulbs will be effectively banned, we'll need to find a clever solution.
PS: sorry for TMI, but I never want to loose an opportunity to perorate (and hopefully enlighten).