| 摘要 |
PURPOSE:To achieve the adjustment, by confirming lamp display and performing set, through a variable resistor for the proportional band and zero point of a duty ratio control and a changeover switch for the duty cycle time, in a cooling or heating device. CONSTITUTION:In a controller, the proportional band of operation rate to external temperature can be increased by adjusting a variable resistor VR3 and increasing the feedback amount to an inverting input of a differential amplifier 6. The zero point is adjusted by a variable resistor VR2. The desired period for the duty cycle time of the duty ratio control is obtained by selecting a switch SW3 in a saw-tooth generator 5. Through a contact (a) of the switch SW3, a shorter time than the duty cycle as a test cycle can be obtained. The output side of the amplifier 6 is provided with light emitting diodes L1, L2 and the output side of a comparator 8 is provided with light emitting diodes L3, L4. Thus, the output state of a signal at adjustment and control operation can be recognized visually. |
