Improvements in and relating to heaters

摘要

The problem of the matching of the output of a space heater RL to the rise in ambient temperature resulting from the use of the heater is dealt with by controlling the supply of energy to the heater by means of an energy regulator fitted with a manually operable control VR to preset the maximum rate at which the regulator can feed energy to the heater. The energy regulator also incorporates a temperature sensing device TH1 that monitors changes in ambient (room) temperature and adjusts the energy regulator accordingly, reducing the mean power fed to the heater by the "burst-fire" control of triac T1 as the sensed temperature rises. The circuit shown operates by comparing the voltage at pin 5 of an integrated circuit with that at pin 4. The latter voltage depends on a divider circuit preferably incorporating a second temperature sensitive device TH2 and is a threshold voltage with which the ramped voltage on pin 5 is compared. The heater may be a radiant or convector heater, or a cooker element.