| 摘要 |
PURPOSE:To prevent overcharge and the like of an auxiliary battery by eliminating the signal lines for detection being connected with the terminal of the auxiliary battery thereby eliminating disconnection. CONSTITUTION:When a load 4 is applied through the use of an auxiliary machine, for example, output current I0 from a DC-DC converter 1 increases and thereby the voltage VR1 across a current detection resistor 9 connected between a rectifier circuit 3 and an auxiliary battery B2 increases. Consequently, the voltage VR at the voltage dividing point of resistors 76, 77 increases over a reference voltage Vref divided by resistors 74, 75 and thereby the output from a feedback amplifier 72 lowers to drop the potential at the inverted input terminal of a comparator 71 which outputs a pulse signal of high duty ratio upon receiving a signal from a triangular wave oscillator on the noninverted input terminal thereof. The pulse signal is inputted to a Tr 5 through a resistor 6 and the output voltage Vc of the DC-DC converter 1 increases as compared with a state VC1 where the load 4 is not connected. |
