AC is what the power transmission grid is, not DC. DC can't be run hundreds of miles (the limit in Edison's time was six miles), and AC can.
Some home devices (electronic ones) do indeed convert AC to DC. Motors are almost all AC.
detailed concise biography of Steinmetz.What is the max. length of a USB 2.0 cable?It is worth noting that in the case of transmitting power over wires, the loss of for DC is quite a bit less than for AC. Steinmetz was mentioned above. Steinmetz drove Edison nuts because Edison loved the idea of low loss DC power transmission. Steinmetz however won the day for one reason: AC lets you change the voltage of the power you are transmitting very simply and economically by using passive power transformers. This let them greatly raise the voltage and reduce the current for the long hauls then at the remote destinations reduce it back down to the desired levels. Doing this AC was the better choice and Edison lost the argument.
jwcrim
7-25-2005 01:33 AM
We still have tons of universal motors, brush type, AC/DC; you probably have two of them in your PC.