| 摘要 |
PURPOSE:To increase the feedable distance of circuit and to miniaturize the size of the circuit, by realizing a circuit that is capable of a conversion of voltage with a small loss and without using any rectifier, etc. and using this circuit for a telephone terminal. CONSTITUTION:The middle point of the transformer T of a voltage converting unit CVTU is connected to a terminal O of intermediate potential, and both ends of the transformer T are connected to terminals C and D alternately according to the transfer of polarity of a transfer switch SW that performs the transfer of polarity in a prescribed period. A DC power supply E is connected between the terminals C and D, and load currents Ia and Ib are supplied to load resistances Ra and Rb from the terminals O, C and D with the equal division of DC voltage V1 and V2. Then the voltage V of the power supply E is equally divided at all times by the transforming function of the transformer T in case the resistances Ra and Rb are unbalanced and the currents Ia and Ib are not equal to each other. Thus the voltages V1 and V2 are always equal to each other. As a result, the feedable distance of a voltage converting circuit is extended with the miniaturization of the circuit attained with no use of a rectifier, etc. |
