Temperature controller for providing a rapid initial heating cycle using a variable reference voltage

Claim 1

A temperature control apparatus suitably applied to flat heating equipment which includes a flat heat-retaining member such as a blanket, a heater wire disposed inside said heat-retaining member, and a sensor wire arranged inside said heat-retaining member to generate heater temperature data corresponding to a temperature of said heater wire, said temperature control apparatus comprising: (a) first circuit means for selectively generating first data representing a first temperature corresponding to a desired target temperature of said heat-retaining member and second data representing a second temperature which is higher than the first temperature by a constant degree independently of the desired target temperature of said heat-retaining member; (b) second circuit means, connected to said sensor wire, for generating a temperature detection signal having a signal level corresponding to the heater temperature data; (c) third circuit means, connected to said first and second circuit means, for comparing the detection signal with one of the first and second data as reference temperature data, and for preventing power supply to said heater wire when the signal level of the temperature detection signal exceeds a level of the reference temperature data; and (d) fourth circuit means, connected to said first and second circuit means, for controlling said first circuit means so as to generate the second data in an initial period after said flat heating equipment becomes operative and to continuously generate the first data after said signal level of the detection signal has reached a level corresponding to the second temperature, said fourth circuit means automatically generating the first data in the initial period when the heater temperature data is higher than said desired target temperature of said heat-retaining member.