Abstract: A plurality of batteries connected in series are monitored by a plurality of monitor devices, respectively. The monitor devices are connected in series to communicate under the daisy chain communication system. The daisy chain communication system includes a micro-control unit for producing a binary signal, a communication device for converting the binary signal to a pulsating signal. The communication device produces a special code based on an instructions from the micro-control unit. Each monitor device changes between a communication OFF state and a communication ON state. Each monitor device has a signal detector which operates during the communication OFF state and detects the special code, whereby upon detection of the special code, the signal detector generates a wakeup signal so that the monitor device is changed from the communication OFF state to communication ON state.

Abstract: A plurality of batteries connected in series are monitored by a plurality of monitor devices, respectively. The monitor devices are connected in series to communicate under the daisy chain communication system. The daisy chain communication system includes a micro-control unit for producing a binary signal, a communication device for converting the binary signal to a pulsating signal. The communication device produces a special code based on an instructions from the micro-control unit. Each monitor device changes between a communication OFF state and a communication ON state. Each monitor device has a signal detector which operates during the communication OFF state and detects the special code, whereby upon detection of the special code, the signal detector generates a wakeup signal so that the monitor device is changed from the communication OFF state to communication ON state.

Abstract: A DC-DC converter system that can switch between BOOST and BUCK operation is used in a power failure prevention system. The DC-DC converter operates in BOOST mode at startup. It charges a storage capacitor via an inductor having its peak current controlled, together with a soft start ramp to limit the power supply in-rush current. During power failure, if the storage capacitor is charged above a pre-determined threshold and the input power supply discharges below a programmable threshold, the DC-DC converter switches from BOOST to BUCK mode, detectable through an internal power detection circuit; its output may also control an external/internal power switch that isolate the input main supply from the power bus. The BUCK mode converter will then dump the charges from the storage capacitor back to the power bus. The BOOST to BUCK mode seamless switchover is achieved through an analog/digital multiplexer that simplify the circuit implementation.