| 摘要 |
PURPOSE:To secure the lighting of the display unit wihtout giving the evil effect to the control power source, by allotting in the time-division way the voltage extracted to the voltage forming circuit to the control power source part side and the display unit side when the coin throw-in urging signal is delivered. CONSTITUTION:When output (a) of coin throw-in urging signal sending circuit 61 is caused, output (d) of NAND circuit 63 becomes L only when output (a) plus outputs (b) and (c) of clock circuit 62 all become H. And photo coupler PC operates to turn on transistor TR2, and thus diode D9 is turned off along with TR1 turned off. Thus charging voltage (f) of capacitor C2 begins to lower. However, output (d) of circuit 63 thrns to H according to the cycle of signals (b) and (c) and when either one of these two signals is L. As a result, TR2 is turned off, and display unit DP is turned off. And the oscillating action of TR1 starts again, and voltage (f) is recovered immediately. Thus unit DP is displayed brightly and by flickering via the call current. Then the duty ratio is set properly to avoid no effect virtually to voltage (f). |
