Blog 9: Travel Voltage Converter

Once again reliving my memories of my trip to Vietnam, I now see the physics behind one of the most overlooked yet important pieces of travel equipment: the voltage converter. 

The many faces of an unsung hero

Because different nations have different power systems, the voltage that is contained in power outlets is not always the same. The voltage in Vietnamese power outlets is 220 V, whereas American power outlets run at 120 V. 

The voltage difference presents a major problem. If you plug in your American device, which is constructed to run on 120 V, into a 220 V outlet, there is a difference of 100 extra volts that flow into your device. That voltage difference, as we were warned by Mr. Brown (a trusty veteran of Vietnam travel), could cause the entire hotel to black out, and fry your device.

Now, what is more important here?

Wait - 100 V isn't very much, considering that a Van de Graaff generator can produce about 400,000 V. So how can 100 V cause such a stir?

Well, voltage is a ratio of energy to charge. The Van de Graaff may produce 400,000 V, but the ratio may be 40 joules / (1/10000) Coulomb. However, 100 V in a power outlet could mean 100,000 joules / 1000 Coulombs, which means that there is a large amount of electrons, and thus a large amount of energy. That is why 100 volts running through your device could mean doom for its circuitry. 

During our first night's stay, some idiot forgot to use a converter, so Tan My Dinh Hotel had a black-out. Though someone got stuck in the elevator, the worst part about the black-out was the absence of TV or air conditioning for an hour. Lesson learned - don't go traveling without a voltage converter!

Blog 8: ASIMO

Honda's ASIMO ("Advanced Step in Innovative MObility") humanoid robot is certainly an interesting piece of technology. While in Japan for a 12-hour layover (returning from Vietnam), our tour group had the opportunity to meet Mr. ASIMO. He greeted us with a few 'words.'

'What, is this blog late?'

"Of course not."

ASIMO was able to walk, run, use non-vocal expressions, and he could even dance. I'd say that makes him pretty human, because I definitely can't dance as well as him.

What made ASIMO incapable of ever being a human, however, was his peculiar stance: he could not stand still without having his 'knees' bent. 

"Am I not human? But I can cry..."

As it turns out, ASIMO, with all of his robotic gadgetry crammed into his back panel, has a center of mass located slightly behind his heels when he stands up straight. Therefore, the torque caused by his mass would cause him to rotate and fall over. To compensate, his designers forced him to be bent-kneed at all times in order to keep his CM inside of his support base and to protect his expensive circuitry. 

Thus, for self-preservation, ASIMO continues to be a bent-legged robot, suited for waiting tables.

Maybe next time, buddy.