On 8/6/2012 11:59 AM, Monty Shultes wrote: > "I-squared R drop",
I'm sorry, but you are mistaken. Voltage drop is IR. The POWER lost in the resistance of the wire is I squared R. To complicate things even more, the current drawn by any power supply with a capacitive input filter is a pulse, not a sine wave, so the power is the INTEGRAL of the current squared. The current is a pulse because it must recharge the filter cap on each cycle, and most of the current flows at the positive and negative peaks of each cycle. The impulsive nature of the current causes the 60 Hz sine wave to be distorted, creating harmonic distortion. That's why power line leakage current is heard as "buzz" (the harmonics of 60 Hz) rather than "hum" (pure 60 Hz). AND the impulsive nature of leakage current increases the power lost beyond what would be predicted by simple Ohm's law applied to a 60 Hz sine wave -- there's much more power lost at the peaks of the charging cycle. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
