摘要:
In a cordless telephone set, a base unit which itself has no loudspeaker function is made to provide a loudspeaker function at low cost. The base unit 2 has a transmitting circuit 22 for transmitting an aural signal and data to the handset 1 and a receiving circuit 23 for receiving and extracting the aural signal and data transmitted from the handset 1. A line interface circuit 25 coupled to a telephone line 3, a loudspeaker 44, and a selector circuit 28 for switching connection of the aural signal line between the transmitting circuit 22, the receiving circuit 23, the interface circuit 25, and the loudspeaker 44 are provided. In normal use, the transmitting circuit 22 and the receiving circuit 23 of the base unit 2 are connected with the line interface circuit 25 via the selector circuit 28. When predetermined push buttons 17 on the handset 1 are operated, the base unit 2 controls the selector circuit 28 so that the telephone line 3 is connected to the loudspeaker 44 via the selector circuit 28.
摘要:
This invention prevents a deterioration of efficiency of a power supply apparatus due to a semiconductor power supply voltage drop, prevents an increase in wasted power, and prevents erroneous operations due to feeder wire voltage drop. In the mounting structure of electronic circuits having a plurality of busbars as current paths on a printed circuit board, the plurality of busbars have almost parallel portions spaced a predetermined distance apart; a span of the parallel portions of the plurality of busbars is greater than the predetermined distance; and in the parallel portions of the plurality of busbars, the plurality of busbars are connected by a wiring pattern. In the switching power supply apparatus built on a printed circuit board, with its output voltage of less than 2 V and its output current of more than 100 A, a means is provided for making the power efficiency higher than 70%.
摘要:
According to the present invention, variations in characteristic impedance and transmission loss of a signal wiring in a glass cloth wiring substrate can be reduced. There is provided a glass cloth wiring substrate in which signal wirings, plural glass cloth layers, and conductor faces are laminated, and spaces between the signal wirings, the plural glass cloth layers, and the conductor faces are impregnated with resin, wherein the glass cloth layers are formed by weaving bundles of glass fibers in a lattice shape, and the adjacent glass cloth layers are laminated on each other while rotating the warp-weft directions of the glass fibers by a predetermined angle with respect to each other. It is preferable that the rotation angle of the warp-weft directions of the glass fibers of the adjacent glass cloth layers falls within a range from 30 to 60 degrees.
摘要:
This invention prevents a deterioration of efficiency of a power supply apparatus due to a semiconductor power supply voltage drop, prevents an increase in wasted power, and prevents erroneous operations due to feeder wire voltage drop. In the mounting structure of electronic circuits having a plurality of busbars as current paths on a printed circuit board, the plurality of busbars have almost parallel portions spaced a predetermined distance apart; a span of the parallel portions of the plurality of busbars is greater than the predetermined distance; and in the parallel portions of the plurality of busbars, the plurality of busbars are connected by a wiring pattern. In the switching power supply apparatus built on a printed circuit board, with its output voltage of less than 2 V and its output current of more than 100 A, a means is provided for making the power efficiency higher than 70%.
摘要:
A variable delay circuit including delay devices each having a plurality of delay units connected successively, only some of the delay units of the delay devices being connected to a signal transmission line, wherein a delay time is controlled by activating or inactivating the plurality of delay units according to control signals applied to control input terminals provided respectively for said plurality of delay units. A clock signal supply device for supplying a second clock signal to a logic circuit block, said clock signal supply device having a clock signal generator for generating a first clock signal and a reference signal and a phase adjusting means for adjusting the phase of the first clock signal phased on a phase difference between the first clock signal and the reference signal and outputting the phase-adjusted signal as a second clock signal, wherein the phase adjusting unit comprises a first variable delay circuit capable of delay operation in initial adjustment of the first clock signal, a second variable delay circuit, disposed in series with the first variable delay circuit, for performing the delay operation after the initial adjustment, and control circuits for controlling delay times of the first and second variable delay circuits.