Control circuit for central heating radiator thermostat valve - detects temp. adjacent expansion element for comparison with reference voltage to control current for heating resistance

摘要

The control circuit uses an electrical heating resistance (4), coupled to a current source, associated with an expansion element (1), for temp.-dependent adjustment of a working piston (2). The expansion element (1) is also associated with a temp. sensor (6) supplying a signal to a regulator (7) also receiving a reference voltage corresponding to a given position of the working piston (2), the output of the regulator (7) controlling a switch (5) between the heating resistance (4) and the current source. Pref. the temp. sensor (6) comprises a negative temp. coefficient resistance. ADVANTAGE - Improved room temp. regulation accuracy.