| 摘要 |
PURPOSE:To protect a DC power supply device from an overvoltage by detecting the overvoltage when a positive output terminal short-circuits to a negative output terminal and a negative output is clamped to the positive side. CONSTITUTION:A first diode D1 only passes an electric current flowing to a ground terminal GND from a photocoupler PC and a fourth diode D4 only passes an electric current flowing to the photocoupler PC from a negative output terminal -V. In case a positive output terminal +Vn short-circuits to the negative output terminal -V and a negative output is clamped to the positive side, the electric current flows to the ground terminal GND from the terminal -V through a resistor RN, the fourth diode D4, the photocoupler PC, and the diode D1 in this order and, as a result, an overvoltage can be detected. Therefore, a DC power unit can be protected from the overvoltage. |
