public function output12v()
{
$input = $this->inputPower->getPower();
$unit = $this->inputPower->getUnit();
if ($input < self::TARGET_POWER) {
throw new \Exception('输入电源不能小于' . self::TARGET_POWER . $unit);
}
echo '电源适配转换开始，输入电源：', $input, $unit, PHP_EOL;
$output = floor($input / ($input / self::TARGET_POWER));
echo '电源适配转换结束，输出电源：', $output, $unit, PHP_EOL;
}
public function __construct()
{
parent::__construct(self::POWER);
}