Abstract: A system for operating a plurality of motors with a single controller is disclosed. This system includes a first motor, a second motor that is matched to the first motor but has a lower power rating than the first motor and a controller electrically driving the first and second motors with a modulated voltage at one frequency selected from one or more frequencies over a complete range of frequencies. The controller generates a frequency of the modulated voltage from the range of frequencies which is proportional to the desired speed for the first and second motors. A method for building such a system is also disclosed. This system and method have particular application to HVAC systems.

Abstract: A meter reader for reading a meter by reading a shadow made by a meter pointer on the face of the meter. The meter reader includes a light source for shining a light toward the meter, a pulse control circuit for pulsing the light source, two light sensors for receiving reflections of the pulsed light from two sections of the face, a detection circuit for detecting the intensity of the reflections received by each of the sensors, a microprocessor system for calculating an intensity relationship between the intensities received by each of the sensors, a counter for incrementing a meter readout count when the intensity relationship varies indicating that the shadow has passed over both sections of the meter face, and a transmitter for transmitting the meter readout count in a meter readout signal.