brush your chucks!

sunday, november 12th, 2023.

Short post today!

I was complainin' offhand about my dirty Chuck Taylor All-Stars the other day and my partner suggested I brush them with a toothbrush and toothpaste.

The difference between a brushed Chuck Taylor and a dirty one.

Yep! It works. I'm so tickled by this. I don't know why I never thought to brush my shoes before. It seems so darned obvious in retrospect! 😅

measuring energy usage with a multimeter.

My multimeter reading 0.30 amperes.

The topic of the monthly cost of running a 10-inch electric fan came up. I don't know why this particular bug crawled up my proverbial butt, but I had to know the answer.

The fan in question, some Honeywell something or other, didn't have a label indicating its power draw. But— I have a multimeter that can measure an AC current up to 10 amperes, some speaker wire, a ground fault circuit interrupter (GFCI) outlet in my bathroom, and a propensity for sticking metal objects in outlets.

Well, after the fan's motor overcomes the inertia of starting the fan spinning, the low speed setting draws 0.3 A and the high speed setting draws 0.45 A.

The Internets tells me that the formula for converting amperes to kilowatts is:

P_(kW) = PF I_(A)× V_(V) / 1000

So, with a power factor (PF) of 1, a current (I) of 0.3 A, and a nominal mains voltage (V) of 120 V, this fan is drawing 0.036 kW. Given my power company's kilowatt-hour (kWh) rate of 10.55¢, this thing costs me about 0.38¢ per hour to run. 9.12¢ per day, and $2.73 per 30-day month. If I run it all the time.

To put the fan's low-speed power draw of 36 watts into perspective, that's less than most incandescent light bulbs. Which makes sense, I suppose, since they heat a friggin' filament to a couple thousand degrees Celsius. What blows my mind is this: a bicyclist can generate something like 100 watts during a sustained effort, i.e. not sprinting.

If I'm doing my monster math right, that means that you could conceivably power a bicycle with three of these dinky little desk fan motors and the right gearing. What I'm learning from this thought exercise is this: bicycles are incredibly efficient machines! Like... I can schlep my commuting gear around town at 12-15 miles per hour using three electric fan motors' worth of power.

Mind blown.

Until the next time such a strange light bulb turns on in my mind, be well! 😅