| 摘要 |
PURPOSE:To reduce the power consumption of the supervisory circuit by actuating the coin supervisory unit consisting of the luminous element and the photo detector only at the necessary time such as the hook-off time or the like. CONSTITUTION:When hook switch HS is turned on, luminous element EL2 has light emission. And photo detector PT2 is turned on with voltage Vpt2 turned to the L level. In case the coins stop dut to the wrong throw-in of the coins and other factors, Vpt2 changes to the H level. This output is applied to NAND1, and the pulse output of initial set circuit IRS which receives voltage V caused by the loop current is applied also to NAND1. Accordingly, NAND1 generates the output of the L level to set FF1 via NOR1. With this output the SCR parallel to impulse contact D1 is turned on the block the dial transmission. At the same time, the presence or absence is checked under transmission of other dials. In such way, the coil supervisory unit is actuated only when necessary in order to reduce the power consumption. Thus the power supply from the exchange suffices. |
