Patent ID: 6109532
Filing Date: 2000-08-29
Classification: B60H,G05D

Abstract:
A locomotive cab heating system comprising:a fan;a supply duct connected to the fan to convey air from the fan to a locomotive cab;a plurality of separately actuated heating units positioned in the supply duct to heat air from the fan in the duct;a temperature sensor positioned into the supply duct;a microcontroller operatively connected to the fan, the heating units, and the temperature sensor; anda memory device storing a program configured to control the microcontroller to perform the steps of:obtaining a temperature reading from the temperature sensor;switching on substantially all of the heating units responsive to the temperature reading being below a lower limit temperature;switching off a first predetermined number of the heating units and waiting a predetermined period of time, then obtaining a second temperature reading, responsive to a temperature reading reaching a selected upper limit temperature on the rise;switching off substantially all of the remaining heating units, responsive to the second temperature reading still being above the upper limit temperature; andswitching on a second predetermined number of heating units responsive to the temperature reading reaching the upper limit temperature on the fall.