Temperature controlled electrical power supply apparatus

摘要

Temperature controlled electrical power supply apparatus for heating carpet-joining tape of the type having a conducting foil adapted to be heated by electric current to melt adhesive thereon includes first control circuitry for receiving A-C power supply voltage and a first adjustable resistor to provide an adjustable high current output. A switch is parallelly connected with the first normally open contacts of a first relay and actuated by the closure of a switch with second normally open contacts of that relay closed to enable the high current output. Second control circuitry includes a thermistor adapted to be connected in thermal contact with the foil such that the high current output is interrupted when the temperature of the foil reaches a preset temperature so as to maintain the foil temperature substantially constant. An SCR includes a gate circuit connected to the thermistor for controlling a second relay to interrupt the high current output.