| 摘要 |
<p>A device for automatically controlling the temperature of welding bands consisting of a dividing circuit for determining the temperature of the welding band. A controller is provided to control the output power of the heating circuit in dependence upon the deviation of the determined actual temperature of the welding band from a predetermined desired value. The output voltage of the dividing circuit is an analog voltage representing the high-temperature resistance of the welding band, and is applied to a second dividing circuit with an analog voltage representing the low-temperature resistance of the welding band. This generates an analog voltage representing the quotient of the two input voltages of the second dividing circuit. This output voltage is multiplied in a multiplying circuit with the output voltage generated by an analog adder as the sum of an analog voltage representing the low-temperature at which the low temperature resistence of the welding band has been measured and an auxiliary analog voltage, which represents a calculated auxiliary temperature. A first subtracting circuit provides for subtracting the auxiliary voltage from the output voltage of the multiplying circuit and for generating an analog voltage which represents the actual temperature of the hot welding band. A second subtracting circuit is provided, which generates a differential voltage representing the difference between the analog voltage representing the determined actual temperature of the welding band and the analog voltage representing the predetermined desired temperature of the welding band and applies this differential voltage to the controller.</p> |
