AUTOMATIC HEAT REGOULA

TORS, more properly automatic temperature regulators, are devices used in connection with heat generating apparatus to maintain a constant temperature of the object heated. The use of such regulators on house heating systems, incubators of various kinds, drying rooms for lumber, fibre and paper products is quite common. Usually the regulator consists of some mechanical element sensitive to temperature variations, which controls either directly or by means of contacts and electromagnets, some force sufficiently large to operate a damper, steam valve, gas valve or whatever is nece ary to vary the amount of heat generated. The force employed may be derived from almost any source, usually falling weights, spiral springs or air or water pre ure is used. The controlling element is often composed of two strips of di imilar ‘metals having different coefficients of expansion, riveted or welded together. Such a composite strip will bend in one direction when heated and in the other when cooled, and forms a convenient controlling device called a thermostat. When a regulator is fitted to a domestic heating furnace, of times @ clock is incorporated in the system 60 as to a soa the dampers, and thus warm the house before the occupants arise in the morning.