HOT AND COLD WATER MIXING VALVE DEVICE

摘要

PURPOSE:To minimize both the overshoot and undershoot and to prevent previously the hunting phenomenon by setting plural switching temperature levels for change to a high speed from a low speed and changing these temperature changes every time the temperature exceeds the reference levels at the positive and negative sides. CONSTITUTION:The switching temperature setting value (a) between the low and high speeds is set by a switching temperature setting/changing means 25 and the value satisfying a1<a2<a3 among these three switching temperature values is set at the positive and negative sides respectively. Then the value (a) is changed as a1 a2 a3 at the positive side and -a1 -a2 -a3 at the negative side respectively every time the switch signal Sw is transmitted from a switching command means 24. A memory control means 27 usually performs the control so that a low-speed characteristic curve is read out of a ROM 28. However the means 27 changes the address so that the low-speed characteristic curve is changed to a high-speed characteristic curve when the temperature difference T between the real temperature TA and the set temperature TO exceeds the 1st switching temperature level a1. Then the switching temperature (a) is changed to the 2nd set value a2. Thus the means 27 can produce a prescribed address by using the value a2 as the data.