PURPOSE: To always operate in an approximately optimum element efficiency state with respect to temperature change by switching electrothermal element groups so divided as to obtain optimum element efficiency in response to the temperature difference of heat dissipation faces and heat absorption faces of the groups to series wirings or parallel wirings.
CONSTITUTION: The temperature difference of the heat dissipation faces and heat absorption faces of electrothermal element groups (element modules 1, 2) is detected by temperature sensors 3 - 6 and a controller of a switch circuit 7. Simultaneously, the groups are divided into two modules 1, 2 and the groups divided to a constant-voltage power source 8 by a switch circuit 7 are switched to series wirings or parallel wirings. The groups divided to obtain optimum element efficiency in response to the temperature difference of the heat dissipation faces and heat absorption faces of the groups are switched to series wirings or parallel wirings. Thus, it can be always operated in an approximately optimum element efficiency to the temperature change.
FUJIWARA KENICHI
NISHIZAWA KAZUTOSHI
SHIROTA YUICHI
