| 摘要 |
<p>PURPOSE:To prevent malfunction, and to simplify constitution by making a power supply device operate only when an output voltage is over a prescribed value for load. CONSTITUTION:A first operational amplifier 1, a second operational amplifier 2, a voltage devision circuit 3, and an integration circuit 4, a control circuit 5, a rectifying smoothing device 10, and a DC-DC converter 20 are provided. Then, the first and the second operational amplifiers 1, 2 are used in the state of 'initial low', and simultaneously, by using difference between the output voltage of the DC-DC converter 20 and the internal voltage drop portion of the first operational amplifier 1, the operation of the load such as a computer, etc., is limited to only the time when its supplied voltage is higher than the prescribed value. Thus, the malfunction can be prevented, and in addition, the power supply device of simple constitution can be obtained.</p> |
