| 摘要 |
<p>PURPOSE:To obtain an oscillating circuit of simple constitution for remote measurement of line loss, by composing the oscillating circuit of a rectifying circuit connected to a line, a switching circuit for short-circuiting the line, a smoothed DC power supply circuit, and an oscillator. CONSTITUTION:A constant current is supplied from the constant current source 14 of a station 11 to a remote station 12 through a line 13 to drive an oscillating circuit 16, which sends an oscillation output with a prescribed constant level to the line 13. At the station 11, the level of the oscillation output transmitted through the line 13 is measured by a level measuring instrument 15 through a filter 17 to measure the loss of the line 13. The circuit 16 is connected to the line 13, and consists of a rectifying circuit 31 for stopping a reverse current, a switching circuit 32 for short-circuiting both wires of the line through a resistance R1 at the oscillation period of an oscillator 34, a power source circuit 34 for applying a smoothed DC voltage to the oscillator 34, and the oscillator 34 for supplying an oscillation output for determining the switching period of the circuit 32.</p> |
