While not obvious to the eye, nevertheless this catastrophe may be detected by the nose, as the smoke that is the substance of mind has a characteristic odour.
Which brings me to my latest experiments.
I had grown impatient with the device to move the limbs – it was noisy, it shook and howled. The motive power for it required far too much Coulombic Fluid. Although I have a source of such, it is bulky and I did not want to use it for the final installation. The motive heart spun at a furious rate, requiring mechanical reducing, and lacked a way to delicately control it. I attempted to grant my machine a kinesthetic sense, but the shaking of the whole device rendered these organs worthless: they could not distinguish between the motion of the shaft and the overall vibration.
I was aware, of course, of a different kind of motive power – a “stepper” which, rather than merely spinning, could be made to advance forwards in fine steps (one forty-eighth of a revolution, in fact). I had avoided these, as the other motors (‘motor’: that which provides motive power) were far simpler. Additionally, these “steeper motors” required a mind/body barrier.
But I had needed a barrier anyway when working with the simpler motor, so it was much of a muchness. And although the stepper is more complex, the mathematics of it were by no means beyond me. It was the correct tool for the task at hand, and I simply felt up to the challenge. And so, once more to the graveyard, coin in hand, for the purchase of a stepper motor and a darlington array chip.
First, the mind! I made use of a certain well-known library for such problems, the one that the italian gentlemen who manufacture my mechanical brain supply. I desired to see what manipulations it would attempt to perform on the motor, and so I attached to the brain certain devices (light-emitting diodes, or LEDs) that glow in the presence of motion in the electrical fluid, and which are sensitive enough to do so in response to the subtle currents of the mind.
Observing the behaviour of the brain, and consulting with the excellent information with which the motor came supplied, I determined how to instruct the mind to operate the motor.
At which point it came time to attempt to use the mind/body mechanism, the “darlington array”. I reasoned that to start with, rather than using the powerful currents that animate the body, I could use the potential of the brain – five voltaic units – as its output, as I merely wanted to see that the damn thing worked at all. I moved the taps that were connected to the LEDs to the array, and put the LEDs on the output of the array.
And all was as it should be! When I directed the mind to move its limb, the LEDs illuminated in correct sequence.
Now it is usual, when LEDs are used, to equip them with a prophylactic whose function is to resist an excess flow of Coulombic Fluid. Such a prophylactic reduces the brightness of the LEDs, but not by a great amount. However, I had disdained this, principally because it is rather fiddly to install the devices – my eyes and fingers are not so precise as they once were. As the darlington array was connected to a mere five volts, this was not an issue.
But the whole point of the array is that it can manage a far greater voltage. That it whole point of it. And so I connected the array to the full unmoderated nine volts of input potential. Within seconds, the LEDs flickered and went dark, and I smelled the smoke. Something had died.
But as you have gathered, I had merely fried the LEDs. One of them still worked, although barely, and was illuminating and darkening in the correct sequence, and so I saw immediately that the brain was uninjured. On the whole, a cheap and instructive lesson.
After this, I connected the motor to the mind via the array (the motor must not be connected directly to the mind under any circumstances due to the phenomenon of back-EMF), and the brain controlled it quite handsomely. I commanded it to spin the motor forward and back by one revolution pausing for one second in between, and the motor accurately turned by a revolution and returned precisely to its starting point. Formidable!
And so matters stand. I believe the motor is quite a bit stronger than the previous ones, which rely on rotational speed. Thus, I shall be able to remove quite a bit of the gearing from The Machine. I suspect I could connect the motor directly to its destined load, but I have been to quite a bit of trouble to source the “Meccano” and damn it – I intend to use it irrespective of whether it is actually necessary.
Further developments anon.