The invention designs an automatic
temperature control circuit which has exact control, reliable and stable performance and complete protective measures, and is used for executing effective real
time control on the temperature of a tube core of a pump
laser in ASE
broadband light source. The control device adopts the
design proposal of a
temperature control system based on
Proportion Integration Differentiation (PID) control and pulse-width modulation (PWM) braking mechanism and realizes the designs by adopting a pure hardware circuit; the control device comprises a reference
voltage circuit, a pumping tube
core temperature testing circuit, a thermoelectric
voltage amplifier circuit, a
PID controller, a pumping
refrigeration current limiting protective threshold set circuit, an efficient PWM control driver, a pumping
semiconductor refrigerator and a pumping tube
core temperature out-of-limit close protective circuit. The whole circuit has simple and compact design, high reliability as well as heating and refrigerating efficiency, and little
self heating, thereby greatly reducing the
power consumption and volume of a pumping temperature controller; as the control device has the complete protective function, when the temperature of the pumping tube core exceeds the set range of
operating temperature, the circuit sends out the gang
control signal to automatically close a drive circuit of the pumping. The pumping
refrigeration current limiting protective circuit limits the
refrigeration current within the range of the preset maximum refrigeration
current range to prevent the pumping from being damaged.