20-09-2017, 02:52 PM
This circuit is designed by 555 Timer IC timer and a decade counter. The timer generates pulses and these pulses are fed to the counter of tens of ten stages.
The ten DECADE COUNTER scenarios have a TEN memory. You can count up to ten pulses. So for every peak in the clock, the counter admits it as an event and remembers it. The number of events that the memorized counter outputted by the corresponding pin.
Circuit components
• Power supply voltage + 9v to + 12v
• 555 IC Timer
• Resistances of 1KΩ, 10KΩ, 220Ω (3 pieces),
• Capacitors of 10μF and 100μF
• RED LED (4 pieces), BLUE LED (4 pieces) and YELLOW LED (4 pieces)
• CD4017 Decade Counter IC
• IN4007 Diodes (8 pieces)
Circuit diagram and explanation
The diagram above shows the four-way circuit diagram with 555 Timer IC. The timer here generates pulses of a time period of about 100 ms. So the power on time is 50 ms and the power off time is 50 ms. This duration can be changed by changing the value of the capacitor. Although the street lights have a change time of 2 minutes, here we are reducing the time to test the circuit.
The change of time for a four-way traffic light can be achieved in this circuit by replacing the 10 uF capacitor with a 470 uF capacitor. Once the power is tuned, the timer acts as a square wave generator and generates clock, this clock is fed to DECAY BINARY COUNTER. Now, the binary counter of the decade counts the number of pulses given in the clock and allows the corresponding pin output to go high, for example, if the event count is 3 then the pin Q2 of the counter will be high and if 5 is counter the Q4 pin will be high. So for every 100ms there will be a peak, with this peak of the counter's memory gain by one and so is the output.
The diodes here prevent short-circuiting of the counter outputs, say if the count is two with this Q1 will be high (since Q1 is high all other outputs will be low including Q0, Q2) in the absence of diodes, Q1 with the positive voltage gets barely lowered to LOW at Q0 (as Q0 voltage becomes + 0V when Q1 is high) since they are connected to each other. With this short circuit takes place.
So during Q0, Q1, Q2, Q3, the green LED in NORTH and SOUTH will be lit together with RED LED in EAST and WEST. So if we assume the clock is 1Hz, the NORTH and SUD side are marked GREEN to go for four seconds and also the WEST and WEST side are signaled RED to STOP during this time.
When Q4 goes high, the YELLOW LED in NORTH and SOUTH will be on together with the RED LED in EAST and WEST. Therefore, if we assume that the clock is 1Hz, the NORTH and SUD side are signaled YELLOW to reduce the speed for 1 second and also the WEST and WEST side are marked RED to STOP during this time.
When Q5, Q6, Q7, Q7 high, the GREEN LED in STATE and WEST will be ON together with RED LED in NORTH and SOUTH. So if we assume the clock is 1Hz, the WEST and WEST side are marked GREEN to go for four seconds and also the NORTH and SOUTH side are signaled RED to STOP during this time.
When Q4 goes high, the YELLOW LED in STATE and WEST will be ON together with the RED LED in NORTH and SOUTH. So if we assume the clock is 1Hz, the WEST and WEST side are signaled YELLOW to slow down for 1sec and also the NORTH and SUD side are signaled RED to STOP during this time.
The ten DECADE COUNTER scenarios have a TEN memory. You can count up to ten pulses. So for every peak in the clock, the counter admits it as an event and remembers it. The number of events that the memorized counter outputted by the corresponding pin.
Circuit components
• Power supply voltage + 9v to + 12v
• 555 IC Timer
• Resistances of 1KΩ, 10KΩ, 220Ω (3 pieces),
• Capacitors of 10μF and 100μF
• RED LED (4 pieces), BLUE LED (4 pieces) and YELLOW LED (4 pieces)
• CD4017 Decade Counter IC
• IN4007 Diodes (8 pieces)
Circuit diagram and explanation
The diagram above shows the four-way circuit diagram with 555 Timer IC. The timer here generates pulses of a time period of about 100 ms. So the power on time is 50 ms and the power off time is 50 ms. This duration can be changed by changing the value of the capacitor. Although the street lights have a change time of 2 minutes, here we are reducing the time to test the circuit.
The change of time for a four-way traffic light can be achieved in this circuit by replacing the 10 uF capacitor with a 470 uF capacitor. Once the power is tuned, the timer acts as a square wave generator and generates clock, this clock is fed to DECAY BINARY COUNTER. Now, the binary counter of the decade counts the number of pulses given in the clock and allows the corresponding pin output to go high, for example, if the event count is 3 then the pin Q2 of the counter will be high and if 5 is counter the Q4 pin will be high. So for every 100ms there will be a peak, with this peak of the counter's memory gain by one and so is the output.
The diodes here prevent short-circuiting of the counter outputs, say if the count is two with this Q1 will be high (since Q1 is high all other outputs will be low including Q0, Q2) in the absence of diodes, Q1 with the positive voltage gets barely lowered to LOW at Q0 (as Q0 voltage becomes + 0V when Q1 is high) since they are connected to each other. With this short circuit takes place.
So during Q0, Q1, Q2, Q3, the green LED in NORTH and SOUTH will be lit together with RED LED in EAST and WEST. So if we assume the clock is 1Hz, the NORTH and SUD side are marked GREEN to go for four seconds and also the WEST and WEST side are signaled RED to STOP during this time.
When Q4 goes high, the YELLOW LED in NORTH and SOUTH will be on together with the RED LED in EAST and WEST. Therefore, if we assume that the clock is 1Hz, the NORTH and SUD side are signaled YELLOW to reduce the speed for 1 second and also the WEST and WEST side are marked RED to STOP during this time.
When Q5, Q6, Q7, Q7 high, the GREEN LED in STATE and WEST will be ON together with RED LED in NORTH and SOUTH. So if we assume the clock is 1Hz, the WEST and WEST side are marked GREEN to go for four seconds and also the NORTH and SOUTH side are signaled RED to STOP during this time.
When Q4 goes high, the YELLOW LED in STATE and WEST will be ON together with the RED LED in NORTH and SOUTH. So if we assume the clock is 1Hz, the WEST and WEST side are signaled YELLOW to slow down for 1sec and also the NORTH and SUD side are signaled RED to STOP during this time.