| 摘要 |
A heat meter having a resistance measuring bridge whose platinum measuring resistors detect the feed temperature, on the one hand, and the return temperature, on the other hand, having a constant-current source which is voltage-controlled by a reference voltage, having a flow meter in the return branch, having a voltage-frequency converter for the diagonal voltage of the resistance measuring bridge, which generates a pulse sequence having a repetition rate proportional to the voltage, and having a counter for the pulses of the pulse sequence. The technical problem consists in the compensation or balancing of the thermal coefficient by measures of control engineering. The diagonal voltage is fed back as a positive feedback voltage (Up) via an amplifier (10) of constant gain (p). An addition stage (2) sums the reference voltage (Uref) and the positive feedback voltage (Up) and passes on the sum voltage (Uref + Up) at the input of the constant-current source (3). <IMAGE>
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