| 摘要 |
PURPOSE:To provide a power supply changeover circuit of a system configured in duplicate having a very small voltage loss and leakage current and switched uninterruptibly. CONSTITUTION:Emiteres of two sets of transistors (TRs) 1,2 being components of a switch circuit of each power supply are respectively connected to input power supplies 12,13 and bases are connected to a bias resistor 5 through TRs 3.4. The other end of the bias resistor 5 is connected to a GND 15. Collectors of the TRs 1,2 are connected together, and the connecting point is used for an output voltage terminal 14. Moreover, diodes 10,11 are connected in a polarity to block a current flowing reversely to an input power supply and resistors 8,9 are connected to control a bias voltage. Thus, the two power supplies are switched uninterruptibly and the power supply changeover circuit is realized, in which a voltage loss and a leakage current are very small. |
