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Circuit Design Question?

2
2006-08-08 19:58:39, Category: Programming & Design
I need to design a circuit that will count to 3 using a pushbutton and 3 LED's. (1 push, 1 led lights... 2nd push, 2nd led lights, 3rd.... and the 4th push clears it.) I am using a 74175 IC for the counter. Any ideas on how to hook this thing up? Thanks.

Answers

  1. John E

    On 2006-08-08 20:03:56


    correctly?

  2. justme

    On 2006-08-09 06:37:32


    what you need is a shift register. Try this: connections (assuming the 16 pin package): pin 2 to pin 5 pin 7 to pin 12 pin 11 to pin 13 pin 14 to pin 4 LED 1 (anode) to pin 2 (other side of LED to GND) LED 2 (anode) to pin 7 (other side of LED to GND) LED 3 (anode) to pin 10 (other side of LED to GND) push button to pin 9 (other side of switch to GND) a resistor (say 10k) from VCC to pin 9 VCC to pin 1 (and 16 VCC pin) GND to pin 8 (GND pin) This basically takes the Q output from FF1 to the input of FF2. The Q output of FF2 to the input of FF3. The Q not output of FF3 to the input of FF4. The Q not output of FF4 to the input of FF1. The LED's are off of the Q outputs of FF1, FF2, and FF3. The switch is on the CLK input with a pull up resistor. The CLEAR pin is kept high. I havent actually tried this, but just by looking at it real quick I think it will work.