Patent ID: 7167040
Filing Date: 2007-01-23
Classification: H02M

Abstract:
1. A voltage booster device comprising: means for boosting a direct current power source voltage upon receiving a voltage-boosting signal; means for outputting either the power source voltage or a voltage boosted by the boosting means, whichever higher, as an output voltage; first current-conducting means for conducting current when the output voltage becomes higher than a first predetermined voltage set to a level lower than a permissible maximum voltage in the voltage booster device; second current-conducting means for conducting current when the output voltage becomes higher than a second predetermined voltage set to a level lower than the first predetermined voltage; voltage-suppressing means for suppressing operation of the boosting means when current is conducted through either the first current-conducting means or the second current-conducting means; and control means for supplying the voltage-boosting signal to the boosting means when the power source voltage is lower than a minimum voltage set to a level lower than the second predetermined voltage, wherein: the first predetermined voltage is set to a level higher than a nominal voltage of the power source; and operation of the control means and the second current-conducting means is prohibited under a predetermined prohibiting condition.