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Old 12-13-2006, 04:29 AM   #8
Join Date: Jul 2005
Default Power converters II

Now for the more complicated versions:

The standard assumption for beam weapons and jump drives in GURPS Vehicles is that they are powered by energy banks recharged either not at all or by slow power input from the power plant. The latter is not modelled by the items in the GVB repository so far, which is why I'm doing this. This delayed-recharge version of a weapon's power setup means that

(1) the energy banks must be able to store more than one second of a laser's energy requirement. They should be able to store enough that the lasers get through a heavy fight without becoming useless.
(2) the power requirement for the recharging of the energy banks may be much lower than in the example in the previous post, since the power plant doesn't necessarily need to supply all the energy within one second.

Here's an example:
Suppose we have a laser with a total energy requirement of 100MJ in a turret (it doesn't matter how GVB arrives at this total, just use the number). Taking the heaviest fights we can reasonably expect into account, let's say the power converter complex must be able to store 100 seconds of continuous firing (10GJ). The need for this long should be extremely rare in most settings unless it's something like Star Wars. Let's also say that it must be able to be completely recharged within 10 times the time it takes for the laser to deplete it (1000s). Power requirement for this setup would be 10MW instead of 100MW for the continuously powered version, but the capacity of the energy storage needs to be 100 times higher.

Here's how to do it:

Editing the template:
Duplicate the "power converter cell" from the example in the previous post. Rename it to something descriptive like "power converter complex" (an item like this can be described as a transformer/energy bank complex). Activate the vUNITS Parameter by typing "Recharge time (s)" into the "Units Name" field. Change the power-in formula to "vQuantity * vRATING / vUNITS".

As in the example in the previous post, add the new item to the turret with the laser. Enter "1000" into the Recharge Time field (we want the energy bank to be recharged in 1000s). Create a link node, and link "power converter complex->rating = 100x laser->TotalEnergyIn" (we want the energy bank to be able to store 100 seconds of continuous laser fire).

(1) Please note that you don't get a balanced energy budget with the delayed-recharge version, not for the subassembly and not for whole vehicle. But that's not important: if the components and links are set up correctly, and this kind of setup is used for all components that use energy instead of continuous power, such as jump drives and beam weapons, the power usage for the whole ship will be tracked correctly through all components. In the end, just make sure that your power plant matches the power requirement. Everything else will be done by the links and GVB itself.
(2) Each kind of energy-storing item that can be recharged needs its own "power converter" version.
(3) You can use the delayed-recharge version for the simple power converter setup in the previous post, too: Just set both the recharge time and the multiplier in the link node to 1. This way you'll need only one additional item per power storage technology in the repository.
(4) If you use standard GURPS Vehicles rules, it will be necessary to use the delayed-recharge version for space combat lasers, because otherwise, for most spaceships, your power plant will take up too much space and weight, and 90% or even more of it will be used to power the weapons. This would be very inefficient since the lasers aren't used 99% of the time.
(5) The size of the energy banks in the delayed-recharge version is a tactical consideration, especially if the achievable size is limited by technology or economics.
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