Vacuum cleaners

In Instance 12:11, Kimberly Koons asks whether anybody has used a
variable suction device on a vacuum cleaner.  I don't know if this
is what she means, but I have successfully used a variable
transformer attached to a Nilfisk vacuum cleaner--this enables you
to vary the voltage supplied to the cleaner, which varies the speed
of the motor, which varies the suction.  It is very effective.

NB. It needs to be a variable transformer (autotransformer), not a
rheostat or an energy controller such as you have with hotplates
etc.

Barry Knight
English Heritage
London

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                  Conservation DistList Instance 12:12
                   Distributed: Friday, July 24, 1998
                       Message Id: cdl-12-12-002
                                  ***