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So far, we have seen a lot of methods to control 3*3*3 LED Cube without using micro controllers. Here, we will design a simple circuit to create a climbing pattern in a 3*3*3 LED cube using a 555 timer and 74HC4017 / 74HCT4017, johnson counter chip. We had already seen the circuit to control 74HC4017 / 74HCT4017 using 555 timer and the circuit to reduce the number of decoded outputs of 74HC4017 / 74HCT4017. Circuit is completed as shown below.
Pin out diagram of 555 timer.
Pin out diagram of 74HC4017 / 74HCT4017.
Square wave (clock pulse) generated in the 555 timer is given to the CP0 input of 74HC4017 / 74HCT4017. Timing diagram of 74HC4017 / 74HCT4017 is given in this datasheet. From the timing diagram, it is clear that, during the positive transition of clock pulse, HIGH voltage will be shifted in the consecutive output pins (Q0-Q9) of 74HC4017 / 74HCT4017. After Q9, HIGH voltage will again start from Q0.
In our circuit, we don't want all the ten decoded outputs (Q0-Q9). We need only three decoded outputs (Q0, Q1, and Q2). If we need only Q0, Q1 and Q2, after Q2, counting should restart from Q0. That is, we have to eliminate Q3-Q9. A simple trick have to be used to eliminate Q3-Q9. Connect the Q4 output of 74HC4017 / 74HCT4017 to the MR pin of 74HC4017 /74HCT4017. This will reset 74HC4017 / 74HCT4017 when Q3 becomes HIGH. That is, after Q2, counting will restart from Q0. Q0, Q1 and Q2 of 74HC4017 / 74HCT4017 is connected to the anode terminals of 3*3*3 LED cube. Similarly, all the cathode terminals of LED cube are connected to ground.
So far, we have seen a lot of methods to control 3*3*3 LED Cube without using micro controllers. Here, we will design a simple circuit to create a climbing pattern in a 3*3*3 LED cube using a 555 timer and 74HC4017 / 74HCT4017, johnson counter chip. We had already seen the circuit to control 74HC4017 / 74HCT4017 using 555 timer and the circuit to reduce the number of decoded outputs of 74HC4017 / 74HCT4017. Circuit is completed as shown below.
Pin out diagram of 555 timer.
Pin out diagram of 74HC4017 / 74HCT4017.
Square wave (clock pulse) generated in the 555 timer is given to the CP0 input of 74HC4017 / 74HCT4017. Timing diagram of 74HC4017 / 74HCT4017 is given in this datasheet. From the timing diagram, it is clear that, during the positive transition of clock pulse, HIGH voltage will be shifted in the consecutive output pins (Q0-Q9) of 74HC4017 / 74HCT4017. After Q9, HIGH voltage will again start from Q0.
In our circuit, we don't want all the ten decoded outputs (Q0-Q9). We need only three decoded outputs (Q0, Q1, and Q2). If we need only Q0, Q1 and Q2, after Q2, counting should restart from Q0. That is, we have to eliminate Q3-Q9. A simple trick have to be used to eliminate Q3-Q9. Connect the Q4 output of 74HC4017 / 74HCT4017 to the MR pin of 74HC4017 /74HCT4017. This will reset 74HC4017 / 74HCT4017 when Q3 becomes HIGH. That is, after Q2, counting will restart from Q0. Q0, Q1 and Q2 of 74HC4017 / 74HCT4017 is connected to the anode terminals of 3*3*3 LED cube. Similarly, all the cathode terminals of LED cube are connected to ground.
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i have made this circuit is working but the problem is that led glow very dim
ReplyDeletewith this circuit my led glow very dim plzz reply me my mail address is omkarpalav61@gmail.com
ReplyDelete