Refer to Figure 4-9(a). In a simple copy machine, a stop signal, S, is to be generated to stop the machine operation and energize an indicator light whenever either of the following conditions exists: (1) there is no paper in the paper feeder tray; or (2) the two microswitches in the paper path are activated, indicating a jam in the paper path. The presence of paper in the feeder tray is indicated by a HIGH at logic signal P. Each of the microswitches produces a logic signal (Q and R) that goes HIGH whenever paper is passing over the switch to activate it. Design the logic circuit to produce a HIGH at output signal S for the stated conditions, and implement it using the 74HC00 CMOS quad two-input NAND chip.

Figure 4-9

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Paper- sensing switches R Feeder tray sensor +5V AND HII a (c) a 1 kn 49 ΚΩ R (a) Logic circuit P 01● Re D R (b) (d) S-P+QR S-P+QR