| 摘要 |
A description is given of a device for controlling the temperature of an electrical heating element, in particular a planar heating element (26), which has a room temperature control device (22) and an operating temperature setting device (24) as well as a switching device (98) for interrupting or switching on the current flow between a current source and the heating element (26). The room temperature control device (22) has a voltage divider (potential divider) consisting of a temperature-dependent resistor (R3) and a variable resistor (R) and the connecting point (50) between the temperature-dependent resistor (R3) and the variable resistor (R) is connected to an input (52) of an amplifier (54). The output (58) of this amplifier (54) is connected to an input (66) of an AND gate (68). The operating temperature setting device (24) has a step switch (stepping switch) (20), to whose switching steps different electrical resistors (R261, R262, R263, R264) are connected. The second connecting elements of these different resistors are connected together in a switching point (70) and connected in series with a second temperature-dependent resistor (R13) to form a voltage divider. The switching point (70) is connected to the input (72) of a second amplifier (74) and the output (78) of the second amplifier (74) is connected to the second input (80) of the AND gate (68). The output (82) of the AND gate ... Original abstract incomplete. <IMAGE>
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