Regulating output of electrical heater - using threshold valve switch and variable resistor combination to ensure min. RPM of fan motor

摘要

The output of an electric storage heater is regulated by a comparator (5) which relates the actual room temp. (T1) to a preset value determined by a regulator (6). A heating element (4), auxiliary to the main heat source (2), is automatically energised whenever the main source temp. (T2) is below the preset requirement. Control of the auxiliary heat output is achieved by varying the speed of a fan motor (3) via a triac switching unit (17) which also controls the total energy input to the auxiliary element (4). A time delay unit (10) ensures that the system responds smoothly to temp. change or preset command without hunting. USE/ADVANTAGE - Rapid response to temp. command. Optimises energy demand on supply network. Smaller storage core is possible due to relatively fast response to outside influences. Also suitable for storage ovens.