| 摘要 |
PURPOSE:To realize a simple and small-size constitution for a call signal device with a small power loss and high efficiency, by using the signals obtained by intermitting the DC high voltage for the call signal of a telephone. CONSTITUTION:At the switch part 6 the two switches 6a and 6b are connected in series and parallel to the output terminals A and B of the rectifying/smoothing part 3 where the DC high voltage is obtained. When the switch 6a is closed, the switch 6b is open and vice versa. This control of switching is carried out by applying the output signal of the control part 7 through the terminals E and F. The control signal frequency of the part 7 is set to the frequency of the call signal, and the DC high voltage is applied to the bell 5 when the switch 6a is closed. The switch 6b is closed when the switch 6a is opened in the next cycle of the control signal. Then the electric charge stroed in the capacitor of the circuit of the bell 5 is discharged in the route of the terminal C switch 6b terminal D. The bell 5 rings in the frequency of the call signal to store the electric charge in the next cycle. |
