| 摘要 |
<p>Traditional bridge circuits for temperature control in which a temperature dependent resistor is used to detect temperature may suffer from a lack of convergence in reaching stability. According to the invention improvements are obtained in that the temperature dependent resistor (Pt 500) is part of a feedback loop around a first operational amplifier (IC1), and a second operational amplifier (IC2) is coupled as a comparator between a reference voltage and the output of the first operational amplifier (IC1), driving an output transistor (T1) for switching a power relay for the heating current.</p> |
