METHOD TO CLEAN SLIP SWITCH OF SNOW AND ICE BY ELECTRICAL HEATING Russian patent published in 2011 - IPC E01B7/24 

FIELD: transport.

SUBSTANCE: proposed device comprises tubular electric heaters and temperature pickups mounted on frame rails, power supply for said electric heaters from AC circuit with single-phase transformer and automatic controller. Said controller comprises switch connected in power supply circuit of single-phase isolation transformer. Switch control input incorporates relay element with hysteresis characteristic and input connected with comparator output. Comparator first input is connected with frame rail temperature pickup. Besides, there are additional ambient air temperature pickup and nonlinear operating converter, connected in series and to comparator second input.

EFFECT: efficient snow and ice melting, reduced power consumption.

1 dwg