Temperature control apparatus with switching control to prevent malfunction from electrical noise

A temperature control apparatus comprising:

• a temperature detector for detecting a temperature of a heating unit;
• a switching circuit for turning ON/OFF a power supply to said heating unit;
• a decision unit for deciding whether to turn ON or OFF the power supply to said heating unit on the basis of the temperature detected by said temperature detector;
• a first register and a second register;
• a first setting unit for setting a first predetermined value to said first register when it is decided on the basis of the temperature detected by said temperature detector that the power should be supplied to said heating unit;
• a second setting unit for setting a second predetermined value to said second register before said first setting unit sets the first predetermined value to said first register;
• and
• a determination unit for determining whether or not the contents of said second register match the second predetermined value,
• wherein turning ON of the power supply by said switching circuit takes place when the first predetermined value is set to said first register on condition that said determination unit determines that the contents of said second register match the second predetermined value.