| 摘要 |
<p>The present invention aims to provide a power supply device inexpensively, which supplies, from the power supply of the solar cell in which the voltage is high and varies heavily, a necessary stable voltage to the measurement equipment of a low voltage. The present invention provides a direct-current stabilized power supply device that steps down a direct-current input voltage obtained from a solar cell and outputs the stepped-down voltage to a load such as measurement equipment, the device including: a first constant voltage power supply circuit that is of a serial type and steps down the voltage, the first constant voltage power supply circuit being connected to the solar cell and including a constant current limiter circuit; a switch circuit connected to the first constant voltage power supply circuit; a switching-type second constant voltage power supply circuit connected to the switch circuit; and a voltage detection circuit that detects an output voltage of the first constant voltage power supply circuit, wherein, in a case where the output voltage of the first constant voltage power supply circuit is detected, and the detected voltage is equal to or higher than a first determination voltage, then the switch circuit is turned to a closed state, and power is supplied to the load from the second constant voltage power supply circuit, and in a case where the detected voltage is equal to or lower than a second determination voltage lower than the first determination voltage, then the switch circuit is turned to an opened state, and the power supplied to the load from the second constant voltage power supply circuit is stopped.</p> |
