GB1350153A - Device for regulating room temperatures - Google Patents

Abstract

1350153 Temperature regulators ZENTRA ALBERT BURKLE KG 19 April 1971 [2 April 1970] 25995/71 Heading H1N In a room temperature regulator having a bimetal 12 controlling a microswitch 16 with a large switching differential, the bimetal is provided with an anticipatory heating or cooling element 18 and is cyclically rocked by a cam 10 to reduce the differential. The bimetal 12 is supported in contact with the operating button 15 of the microswitch between two pivot points 13, 14. Point 13 is fixed by a temperature setting cam 20 while point 14 is moved by the cam 10 through a follower 25. The cam 10 has a low portion 32 entry of the follower 25 into which is limited by a stop 31 set so that the total deflection of the bimetal by cam 10 is a little greater than the switching differential of switch 16 so that if the room temperature is near to the set value the switch 16 will be switched off during each cycle of the cam. The differential of the switch 16 is made deliberately large so that once the switch is on the room heater 19 cannot raise the temperature fast enough to switch it off again during the cycle of the cam. In addition a further step 43, 45 may be provided on the cam of sufficient depth that the bimetal cannot cool fast enough to overcome the deflection it causes before the end of the cycle so that the switch cannot be switched on during the latter part of the cycle. The steep rise 40 at the beginning of each cycle means that unless the temperature is very close to the set value the switch 16 is switched on close to the beginning of the cycle. Thus, in heating the room, the regulator switches the heater on for whole cycles of the cam but there is a small proportional range close to the set temperature. Since the switch cannot be switched on during the latter part of the cycle the regulator is suitable for controlling gas and oil fired boilers which must be on for a minimum period. For electric heating the step 43, 45 may be omitted. If room heater 19 is replaced by a cooling plant of an air conditioning system the heating element 18 is replaced by a cooling element, e.g. working by the Peltier effect. The cam 10 may be driven by the motor of a timeswitch associated with the heating or air conditioning system.