| 摘要 |
PURPOSE:To minimize power loss in a power supplying circuit and make it easy to make the circuit IC by finding the circuit resistance on the basis of the voltage between lines and circuit current, finding the circuit voltage to apply to the lines with the circuit resistance and deciding the output of a circuit voltage conversion circuit. CONSTITUTION:Power conversion circuit CONV which converts the voltage of power source B to the prescribed voltage and applies the converted voltage to lines L1 and L2 is attached to circuit current supplying circuit LCF which supplies circuit current to terminal device TE through lines L1 and L2. In addition, voltage detection circuit DETV which detects the voltage between lines L1 and L2 and circuit current respectively and current detection circuit DETI are also attached to the circuit current supplying circuit. The circuit resistance between lines L1 and L2 is found with calculation circuit CAL on the basis of the detection output from these circuits DETV and DETI, the circuit resistance is compared with the voltage value outputted from circuit DETV by comparator CMP, conversion circuit CNV is controlled according to the compared result and then the voltage to be applied to lines L1 and L2 is decided to minimize the power loss in circuit LCF and make it easy to make the circuit IC. |
