Thaumaturgic Automata and Draw Power

[scc]

You to missed the point, if they define it in terms of a unit that is rate of change, it's the change that would matter, not the actual amount of energy or power that can be delivered through what ever outlet (Such as a power point)

And things like watt/seconds are around, here, from the wikipedia article on killowatt hour: "Watts per hour (W/h) is a unit of a change of power per hour."

Also I think theres and error on the Technomancer table, in the foot notes it defines a 12 V cell as a car battery (Fair enough, try finding another source/use of 12 V cells), but then it goes on the say that you should halve power available from rechargeable sources

Now would anyone be upset if I took this topic further afield?

[Fred Brackin]

Originally Posted by scc

When updating that section I'd suggest switching to the 360 kW/kJ as the baseline, instead of the 1kWh.

Addationally, and I forgot to say this before, I think that M179 has a typo, looking at that Technomacer table only seems to confirm it. M179 reads: "360 kilowatts (kW) is equal to 1 energy/second, and 360 kilowatt-seconds (kWs) or kilojoules (kJ) is equal to 1 energy." I think it should be 360kW/s is one energy per second and 360 kW is 1 energy

No, this is not how Draw Power works. That's the one that can give you FP per second. it needs a constant flow of 360 kilowatts per second. It's hooking up to a source rated at 360kw that you need.

Steal Power needs a form that's stored. It's the one that would need kilowatt-seconds. Or kilojoules but not kilowatts.

[whswhs]

Originally Posted by Fred Brackin

No, this is not how Draw Power works. That's the one that can give you FP per second. it needs a constant flow of 360 kilowatts per second. It's hooking up to a source rated at 360kw that you need.

I know what you mean, but "kilowatts per second" would not be a constant flow. It would be an increasing flow: 360 kW at the end of second 1, 720 at the end of second 2, 1080 at the end of second 3, and so on. A constant flow would be a steady flow of 360 kW (or 360 kJ/second—the "per second" is already implicit in the unit "kW").

I can't see that it helps sort out this discussion if you use muddled terminology.

Incidentally, GURPS Thaumatology: Urban Magics explains the whole business on pp. 26-27, if you want a fourth edition source. It also provides Minor Draw Power, which can convert 6 kW into 1 FP/minute (at a maintenance cost of 1 FP/minute, so you need 12 kW to have a net gain—still more than most low-tech societies can provide, but a TL(4+1)^ society might have suitable power sources).

Bill Stoddard

[Fred Brackin]

Originally Posted by whswhs

I know what you mean, but "kilowatts per second" would not be a constant flow. It would be an increasing flow: 360 kW at the end of second 1, 720 at the end of second 2, 1080 at the end of second 3, and so on. A constant flow would be a steady flow of 360 kW (or 360 kJ/second—the "per second" is already implicit in the unit "kW").

Measurements across multiple seconds are irrelevant to Draw Power. You can only use Draw Power on a single Turn timescale. There's no accumulating stuff over multiple seconds.

I know Minor Draw Power doesn't follow this rule but it's an entirely different spell. I also know it exists partly because you can't do anything with low tech sources of power without it.

Having double-checked Gurps Magic the term it uses is "power" for Draw Power and "stored power" for Steal Power. You might think it should be using "energy" for that use.

The book does speak of "energy" once but when it does so it's referring to the mage's FP. At least that use doesn't conform to your electrical engineering definitions.

I am not at all sure that Gurps Magic was written to use your technically correct engineering terminology. I suspect that it might be written in Common English, a notably imprecise language.

Nevertheless I do understand how the spells work and your diversions about terminology have not changed how they work..

[whswhs]

Originally Posted by Fred Brackin

Measurements across multiple seconds are irrelevant to Draw Power. You can only use Draw Power on a single Turn timescale. There's no accumulating stuff over multiple seconds.

Which is why you should not use the expression "kilowatts per second," which sounds exactly as if you were talking about a process continued over multiple seconds.

I don't doubt that you actually do understand the physics. But I'm a professional copy editor; I have spent much of my working life reading passages that fail to express concepts accurately—ranging from those where the problem is simple linguistic carelessness to those where the writer has not thought through the actual ideas and is confused about what they are trying to say. I've seen how such text can produce misunderstanding in readers, and indeed one of my most important professional skills is a practiced ability to think of ways in which a sentence could be misunderstood. You may know what you're talking about, but there have been other posts in this thread by people who aren't clear on the physics, or who actually understand it incorrectly. That's not going to lead to useful discussion, not in dealing with a system of rules that do in fact reflect the real world physics and engineering.

Bill Stoddard

[malloyd]

Originally Posted by scc

Also I think theres and error on the Technomancer table, in the foot notes it defines a 12 V cell as a car battery (Fair enough, try finding another source/use of 12 V cells), but then it goes on the say that you should halve power available from rechargeable sources

There actually are primary (i.e. not intended to be recharged) lead acid batteries out there. Mostly in rarely used backup gear where you keep the acid separate from the plates until you want to use the battery too.

[malloyd]

Originally Posted by Fred Brackin

I know Minor Draw Power doesn't follow this rule but it's an entirely different spell. I also know it exists partly because you can't do anything with low tech sources of power without it.

Which is also the reason the entire concept of using real world energy for powering spells is flawed, at least with any sort of linear relationship. The difference in magnitudes inevitably means that if you have a conversion that is balanced for non-portable industrial sources it's going to be utterly useless for batteries or household sources. For that matter if you have one balanced for volcanos, forest fires or storms, it'll be useless for artificial power sources of any sort short of the entire output of TL6+ baseload generating plants.

[scc]

OK, slightly related question: Modern people will recognizes potatoes and other fruits and vegetables as potential electrical sources, and then there's voltaic piles (See High-Tech, page 12, the dirty tech callout)

So how much potatoes do I need for a single point of of FP?

[Anthony]

Originally Posted by scc

So how much potatoes do I need for a single point of of FP?

Probably infinite, due to internal resistance of the cells.

[whswhs]

Originally Posted by scc

OK, slightly related question: Modern people will recognizes potatoes and other fruits and vegetables as potential electrical sources, and then there's voltaic piles (See High-Tech, page 12, the dirty tech callout)

So how much potatoes do I need for a single point of of FP?

That depends on what metals you use for the electrodes. It's not the potato that supplies the energy; it's the difference in electrical potential between the two contacts, made active by the presence of an ionic solution.

Bill Stoddard