Abstract: An object of the present invention is to provide a heat exchanger for a temperature control which can take a large area for transferring the heat to the fluid while it is compact, has a good efficiency for exchanging the heat, can increase and decrease the heat transferring area in conformity to the user's needs and the manufacturing cost thereof is low. The heat exchanging boards 2, 3 with a plate constitution and plural thermo modules are superposed alternately so that they have a laminate constitution. The heat exchanging board has a construction such that a flowing path defining board 5, in which a flowing path with a labyrinth construction is formed, is folded by a thin shell 7. The shell has an inflow hole into which the fluid flows and an outflow hole from which a fluid flows out passing through said flowing path with the labyrinth construction. A peltier element is used as the thermo module.

Abstract: A Peltier element 4 is fixedly brought in close contact with a surface of a heat exchange block 3 with a large heat capacity which performs heat exchange with an end portion 2a of a heat pipe 2, heat transferring means 5 is disposed on a side of the Peltier element 4 which is opposed to the heat exchange block 3, the heat pipe 2 has at least one heat conduction extending portion 2b projecting from the heat exchange block 3, and heating medium about the heat conduction extending portion 2b is temperature-controlled by the operation control of the Peltier element 4 via the heat exchange block 3 and the heat conduction extending portion 2b of the heat pipe 2.

Abstract: The present invention provides open-circuit detection for detecting an open circuit in parallel-connected thermo modules. Plural rows 10a of plural series-connected thermo modules 11a, . . . 11n are connected in parallel. A detection circuit 12 is provided for each row 10a of modules to detect a change in voltage between a power terminal 17a and an intermediate terminal 18 caused by an open circuit. Switching circuits 20 in the detection circuits 12 are connected in series to an alarm circuit 14, so that if any detection circuit 12 detects an open circuit to preclude the corresponding switching element 20 from conducting, the alarm circuit 14 is activated to cause an alarm 32 to issue an alarm.