The Triplett Model 630 A-Volt-OHM-Milliammeter
When I was a kid, I spent endless fascinating hours with my dad in the garage of our southwest Detroit home. The floor-to-ceiling shelves were crammed with boxes of spare parts and electric motors. On the floor and the workbench were large and small tools, acetylene tanks, a grinder, a drill press, and a lathe. My dad was a heating and air-conditioning serviceman, and he loved explaining and showing me how things work: things like his Triplett electrical tester. This black box, with dials, gauges, wires, and switches, looked to my 9-year-old eyes like some exotic scientific instrument from the future.
When trying to explain how volts times amps equals watts, he said, “Robert, picture in your mind a two-hundred-and-twenty-foot water tower.”
“Okay, Dad.”
“Now, say we drill a one-inch hole in the tower, one foot down from top.”
“Okay. Got it.”
“Because there’s not much water pressure just a foot down, it’s not going to squirt out very far—maybe just a lazy dribble. We’ll call that one volt.”
“Gotcha,” I said. “Low pressure—one lousy volt.”
My dad taking a rare break having a beer by his garage
“Now we drill the same size hole a hundred and ten feet down. That water’s going to squirt out a whole lot farther, with a lot more force. That would be like a hundred and ten volts.”
“Sure, Dad, like a lightbulb!”
“Exactly. Every electrical fixture and appliance requires a specific voltage—a certain pressure—to work. Most window air conditioners need a hundred and ten volts, but a house air conditioner needs two hundred and twenty. That’s because the condenser is bigger and needs more energy to compress the freon vapor back into a liquid.”
“So where do the amps come in?” I said.
“Amps are the size of the hole we drilled. If we drilled a two-inch hole, it would have four times the amps, and the product of the two—the size times depth—is watts.”
“Why four instead of two times?”
“Because it’s larger left and right, and up and down.”
“Okay,” I said, trying to remember it all. “But your electric tester says ‘ohms.’ What’s that?”
“That’s resistance. Electricity flows better in copper than aluminum.”
“Can electricity flow in me?”
“Yes, but not very well,” he said, picking up a nine-volt transistor-radio battery from his cluttered workbench. It had double prongs on top, and he touched them to his tongue for a moment. “Put it to your tongue, Robert, and feel the tingle.”
“Is it gonna hurt?”
“No, but you can feel it.”
“Wow, that feels funny!” I said.
But that demonstration just spawned more curiosity. There was something magical about electricity. I couldn’t see it or taste it, but I could see and feel its effect. It was like fire that gave heat and light and could move from one place to another like a living thing. I knew that magnetism could be used to make electricity and that electricity could make magnetism. I had made an electromagnet with a flashlight battery, a small coil of wire, and a nail. So another day, when only my mom was home, I unscrewed a 110-volt lightbulb from a socket in the basement where I slept, and stuck a screwdriver in, holding it by the shank. I can’t say exactly what I was thinking, other than that I wanted to learn. The shock hit me so hard, a big flash went off in my head and I froze stiff. I couldn’t even scream or let go of the screwdriver for several seconds.
It certainly wasn’t a pleasant experience. But in time, I learned that electricity is electrons in motion. An electric current is commonly believed to move at the speed of light, but that isn’t entirely accurate. The speed of sound is a better analogy. Air molecules vibrate into one another, creating a wave effect of 767 miles per hour at sea level.[1] Electricity is similar. The electrons aren’t moving along a wire at the speed of light (186,000 miles per second) but are typically flowing at about fourteen inches per hour. But like air molecules at the speed of sound, they’re vibrating into one another, creating wave forms. These wave forms move at their respective speeds (sound 767 miles per hour, and light at 186,000 miles per second). The life-threatening shock I felt was the zillions of electrons in my body suddenly vibrating into one another at the speed of light.
Through unconventional experimentation, I learned that sometimes, when you push the envelope, the envelope pushes back.
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[1] The electrons surrounding the sphere of an atomic or molecular nucleus in air don’t actually touch but repel one another upon approaching the same negative charge. The same effect happens with electrons in an electric current.
