| 摘要 |
PURPOSE:To prolong service life and to enhance reliability of DC power supply unit by stopping operation of one converter unit when the other converter unit is feeding a load with power and making a switch to one converter unit instantaneously upon drop of output due to failure of the operating converter unit in the switching operation of an overlapped power supply system. CONSTITUTION:A first converter unit 2 operates when the output voltage VOUT1 from the first converter unit 2 is higher than the output voltage VOUT2 from a second converter unit 3. At that time, output voltage VOUT1 from the first converter unit 2 is applied as a detection voltage, through a fourth diode 28 to the joint of two voltage dividing resistors 24, 25 in the second converter unit 3. Consequently, detection voltage V of the voltage dividing resistor 25 in the second converter unit 3 substantially doubles the voltage reference Vref of a reference voltage source 26 thus substantially stopping the operation of the second converter unit 3. The second converter unit 3 resumes operation upon drop of output voltage VOUT1 from the first converter unit 2. |
