Introduction: 555 Knight Rider Circuit
A LED knight rider circuit is fairly popular on the internet and the circuit is also easy to find. This tutorial will show you how to construct the circuit step by step.
This is the final project for PHYS339. PHYS339 focusses on ICs so this project is all about how NE555 AND 4017 circuits work together.
To make the circuit easy to follow, we'll separate the connections to 555 timer and the 4017 decade counter.
Schematic courtesy of http://www.555-timer-circuits.com/
You will need the following components:
NE555 Bipolar Timer
8 x 100 Ohm Resistors
2 x 220 Ohm Resistors
6 x LEDs
4017 Decade Counter
1k Ohm Resistor
68k Ohm Resistor
9V battery and battery clip
3.3 uF Capacitor
Step 1: Background
In this project, the 555 is astable mode. The output is constantly switching between high and low value. We can also change the frequency (which would make the LEDs flash faster or slower,) by changing the value of the resistors (putting a potentiometer would be fun). The output (pin 3) is then connected to the 4017 counter. The 10 outputs of the 4017 counter switch from one to another when 1 cycle of the 555 timer is completed.
Step 2: The 555 Timer
The redrawn schematic is a representation of what the circuit should look like on the breadboard. Pay close attention to what wire coming from what pin to what pin. The longer end of the capacitor (+ sign on the schemic should go to pin 1). Due to the size of the capacitor and the space between rows on the breadboard, the longer end of the capacitor is moved 2 rows up. Pin 3 is for connecting to the 4017 decade counter.
Step 3: 4017 Decade Counter, LED & Resistors
Start by laying down the LEDs and then the resistors. Remember the short end of the LED goes to ground. Make sure to leave some space among the LEDs for the resistors.
Starting from the top, the first LED to D1 down to D6. D1 and D6 are each connected to a 220 Ohm resistor. D1 goes to Q4, which is pin 10 on the decade counter. D6 is pin 3.
Step 4: LED D2
2 100 Ohm resistors go to D2, R8 goes to pin 10, R6 goes to pin 5.
Step 5: LED D3
2 100 ohm resistor, R5 goes to pin 6, R3 other to 7.
Step 6: LED D4
Again 2 resistors, R4 goes to pin 9, R11 to pin 4.
Step 7: LED D5
2 resistors, R3 goes to pin 11, R11 to pin 2.
Step 8: Wrapping Up
Connect pin 3 of the 555 counter to the pin 14 of the decade counter.
Connect pin 16 of the decade counter to + terminal or 9V
Connect pin 15 & 13 of the decade counter to ground
Step 9: Connect Your Battery
Connect your battery and you're done!
2 years ago
Thanks for sharing :)