Uninterruptible power supply having efficient power conversion

An uninterruptible power supply (UPS) having efficient power conversion comprising:

• an AC to DC power conversion circuit having:
• a set of input terminals adapted to be connected to an AC mains;
• and
• a set of output terminals;
• a battery power conversion circuit parallelly connected to the AC to DC power conversion circuit and having:
• a charging circuit having:
• a set of input terminals connected to the AC mains;
• and
• a set of output terminals;
• a first DC conversion circuit having:
• a set of input terminals connected to the set of output terminals of the charging circuit;
• and
• a set of output terminals connected to the set of output terminals of the AC to DC power conversion circuit;
• and
• a rechargeable battery connected between the set of output terminals of the charging circuit and the set of input terminals of the first DC conversion circuit;
• and
• a control circuit connected between the AC to DC power conversion circuit and the battery power conversion circuit and outputting a control signal to activate the first DC conversion circuit when the AC mains fails or unstably supplies power.