6-Way Channel Selector

by U Gunther This design proves that a latch- ing 6-way channel selector with debounced switch inputs need not always be based on the use of special integrated circuits. When none of the break-type SPDT push buttons is pressed, the data inputs of IC, are held at +5 V, while input CLK is held low via R8. When a switch is operated, the associated input of IC, goes low, while CLK goes high, so that the logic state of the Do-Ds lines is latched and transferred to outputs Qe-Q5. Each of these can drive a LED or relay based output circuit as shown. When more than six switches are required, a 74LS174 may be added, whose clock input is connected to IC,. Note that the LS chip may be replaced by a corresponding CHAN SELECTOR R1 19 01 CLK CLR 000x S2 4D1 x 5V 0 S5 12 13D4 4 x 14 D5 15 5x 0, x 62...67 6x 1k Trrrrr IC 1 version from the HC or HCT family. This will reduce the cur- rent consumption from about 20 mA to 6 mA. The maximum output current supplied by ICI is 8 mA in all cases. 6 IC1 D...