Tuesday, July 22, 2008

Current carrying wire

During a recent long and particularly boring meeting I was sitting next to a laptop computer which was plugged in to a wall outlet. I used my magnetic sense to explore power supply, which emitted a now familiar buzz from the small transformer inside it. I was quite surprised to also feel a sensation from the power cable as well, a faint vibration but definitely there.

When current flows through a straight conductor, there is a magnetic field encircling it. In the case of a DC current the field is stable and the direction can be determined using the right hand rule.
An illustration of a DC current carrying wire's magnetic field.

AC current, however, produces an oscillating field which can be picked up with the implant. Having explored several power cords, it appears that low current devices (like light bulbs) don't draw enough current to be detectable. Only higher current draw devices produce the faint buzzing sensation. Also, only the hot wire will yield a sensation, as the neutral wire normally carries no current. The cable type itself plays a large part in detectability too. Shielded cable (predictably) is far less likely to produce a detectable field, as is cable that is enclosed in metal conduit.

Pretty cool, nonetheless.

Tuesday, July 8, 2008

2 Months, all is well, sensation has further improved

Two months have gone my since my implant and all is going well. I have had a few incidents where the implant suddenly hurt when gripping/grabbing an item, but the pain does not linger. Usually it's more of a pinching sensation than anything, which makes total sense given its placement and rigidity. I'm fairly careful with the finger in day to day life, but I don't really worry about the implant rupturing as I would if it were coated in silicone.

The implant has continued to become more sensitive. In cases where I previously just felt faint tingles and buzzes, I now sense subtle variations in fields. The coils on my stove, my microwave, innocuous looking items fixed to building walls... they all have an interesting facet that was invisible to me before. Most of the time I seek them out, bringing my implant close to things that may have a detectable field. Other times I'm caught by surprise. While at a WalMart checkout lane, for example. The product I bought had a theft protection tag:

When the device in the register disabled it (it makes a weird springy "bonnng" sound) I felt a sudden vibration from my implant. It honestly took me a few seconds to figure out what had happened as my hand was quite far away. Those things make quite a strong field, no wonder they tell you to keep credit cards off of them!

Permanent magnets are quite interesting too. I have found myself saying "woah, that's a magnet in there" after feeling the sensation when I reach past or over a concealed magnet. Strong magnets produce an unmistakable tug on the implant, of course, though I find it's far easier to detect a pull than a push. Magnets are quite fun to play with, though I'm becoming increasingly aware of the fact that a very strong magnet could pose quite a problem for me.

A close friend of mine, who initially turned me on to the idea of magnet implants, has finally decided to get one himself. I hope his experience is every bit as awesome as mine has been.