On Thu, 22 Dec 2005 12:13:57 GMT, "david lang"
wrote:

You use induction motors whenever you can - they're quieter (this is a
domestic appliance after all) and they're cheaper.

Odd. The only experience I have is with high pressure cleaners. The el
cheapo DIY jobbys have brush motors which make a terrible screaming noise -
but they use them to reduce costs.

Induction is cheaper for a specific power, or for almost all large
motors. Brushed is cheaper for small low powered motors that still need
high torque. If you can go to a direct-drive design, then using a
brushed motor and no gearbox is usually cheaper, but you need a motor
that can provide the required torque on its own shaft.