Title:
AUTOMATIC TEMPERATURE CONTROL DEVICE
Document Type and Number:
Japanese Patent JPH05134771
Kind Code:
A
Abstract:
PURPOSE:To make it possible to widen a operation temperature range by a simple constitution by amplifying a driving signal to be supplied to a Peltier effect element by an emitter ground amplifier circuit and supplying the signal to the Peltier effect element. CONSTITUTION:When the ambient temperature Ta of a LD element 12 becomes lower than a target temperature TLD to be held, the resistance RTH of a thermistor 13 is increased. By this, a driving circuit 16 composing an emitter ground amplifier circuit decreases current ICOOL flowing in a direction by which a Peltier element 11 is cooled. At this time, current flowing in a diode 17 is increased and the current IHOT of a direction heating the Peltier element 11 which is collector current Ic of a transistor Q8 is increased. After all, current IHOT'= IHOT-ICOOL flows, the Peltier element 11 is heated, the ambient temperature Ta of the LD element 12 rises and a constant state is held. Conversely, when the ambient temperature Ta becomes higher than the target temperature TLD, it works entirely reversely. The ambient temperature Ta is lowered and the constant state is held. Therefore, the setting range IHOT, ICOOL can be enlarged.
Inventors:
ITO ATSUSHI
Application Number:
JP29440491A
Publication Date:
June 01, 1993
Filing Date:
November 11, 1991
Export Citation:
Assignee:
FUJITSU LTD
International Classes:
G05D23/20; H01L35/00; H01S5/024; H01S5/068; (IPC1-7): G05D23/20; H01L35/00
Attorney, Agent or Firm:
Tadahiko Ito (2 outside)