| 摘要 |
PROBLEM TO BE SOLVED: To reduce calorific value of a shunt circuit which controls a shunt current consuming part excessive of an electric power generated from a solar battery, by controlling the shunt current by using a pulse width controlling switching regulator constant-current control circuit to the shunt circuit. SOLUTION: When a bus voltage 103 is higher than a specific voltage value, a bus voltage error detecting circuit 5 detects the error of the bus voltage 103 and outputs a bus voltage error detecting signal 101. Then a control circuit outputs a pulse signal having the pulse width corresponding to the signal 101 and generates a shunt current 102 while the control circuit is controlled by means of a switching regulator 3. The power loss P of the shunt current 10 is expressed by the product (P=Von×Ix×D) of conductingtime voltage drop Von of a switching element, maximum current Ix (switching peak current) of a solar battery 2, and duty ratio D of the conducting time. Therefore, the power loss of a DC control bus power unit for mounting on an artificial satellite becomes smaller as compared with the product of the output voltage of the solar battery and shunt current, because the voltage drop Von is usually a small value of about 1 V or lower. |
