Re: Can electric motors be used as emergency electric generators?tors

Thanks for all of the questions.   ;-)

I have answered the questions in the order in which you stated them.  I 
hope that this is useful.

The most likely reason that the authorities do not suggest using diesel 
engines and electric motors to generate electricity is because this is 
dangerous.  The risks are too great that someone would be killed, 
especially if the power were restored without the user knowing this.  Also, 
most modern electric equipment do not tolerate unregulated voltages -- as 
would be generated in your scenario.  As a matter of fact, portable 
electric generators will shorten the life of most electric equipment.

Electricity will be generated whenever a magnet is rotating inside of an 
coil.  So, most electric motors can produce electricity.

You would have to increase the RPM of the motor in order to overcome the 
effects of hysteresis.  The voltage that can be generated by a motor 
depends a great deal on the size and winding of the coil.  Most motors do 
not require the exact voltage that the label states in order to run 
effectively.  It is not very beneficial to put a rating of, say 100V, on a 
motor if it is going to be used in an environment that only has 120V 
available.  So, in the US all motors designed for domestic use will most 
likely have a rating of 120V.  However, the motor can probably operate with 
a voltage anywhere in the 90 - 130V range.

A motor will not produce DC.  Direct current is obtained by rectifying an 
AC waveform.  What then results is called pulsating DC.  The pulsating DC 
is then filtered to produce "pure" DC.  There are other ways to generate DC 
-- chemically, or by fusion.  But that's a different story.

By varying the speed of a motor, the frequency and magnitude (i.e., 
voltage) of the resulting wave will change.

It is unlikely that you will produce 110V from a similarly rated motor (see 
#3 above).