JPS5752727A - Forced hot air oven - Google Patents

Abstract

PURPOSE: To decrease the frequency of ON-OFF control of a heat source in a forced hot air oven, by changing the heating capacity of a heat source between "high" and "low" in response to ON and OFF of a thermoswitch when the setting temperature of the thermoswitch is higher than a particular value, and thereby enabling to keep the oven warm by heating the same at a low rate even when the thermoswitch is opened.

CONSTITUTION: When cooking is started after setting a thermoswitch 53 at a temperature of 150W300°C, current is supplied to a combustion control circuit 54 via a closed, normally opened contact 53" and an auxiliary switch 55, and a small and a large burners 14, 15 are combusted through operation of an ignitor 59 and opening of a first and a second solenoid valves 56, 57. At the same time, a motor 8 is turned in normal direction, so that hot air in a combustion chamber 3 is circulated into a cooking chamber 2. Subsequently, when the temperature in the cooking chamber 2 reaches the above setting temperature, the contact 53" is opened but the auxiliary switch 55 designed to turn OFF at a particular temperature lower than, for instance, 150°C is kept closed. Therefore, solenoid valve 57 alone is closed by a relay 52, so that the large burner 15 is extinguished. Further, a switch 52' for changing the turning direction of the motor 8 is shifted by the relay 52, so that rotation of the motor 8 is reversed.

COPYRIGHT: (C)1982,JPO&Japio