4017 Light Chaser Kit Instructions
Table of Contents
Schematic
Simulation
How Does The 4017 Light Chaser Work?
The 4017 light chaser is made up of two main circuits; a 555 astable oscillator and a 4017 5-stage Johnson counter. The 555 astable circuit is made up of a single 555 timer, a potentiometer (RV1), a resistor (R1), and a capacitor (C1). This circuit outputs a square wave whose frequency is determined by the resistance of RV1 and the larger the resistance of RV1 the slower the output frequency. You can learn more about the 555 astable circuit with this kit available from MitchElectronics. The output of the 555 astable is connected to the clock input of the 4017 and every time the output of the 555 transitions from low to high the 4017 counter transitions to the next state. The 4017 has 10 outputs that each turn on after the previous output has been turned off. The best way to see this is to look at the table below which shows the output states for each clock pulse that is fed into the CLK pin.
Component List
Component | PCB Reference | Quantity | Looks Like |
---|---|---|---|
8 DIP Socket | IC1 | 1 | |
16 DIP Socket | U1 | 1 | |
555 Timer IC | IC1 | 1 | |
4017 Counter IC | U1 | 1 | |
100nF Capacitor | C2, C3, C4 | 3 | |
100µF Capacictor | C1 | 1 | |
1kΩ Resistor | R1, R2 | 2 | |
10kΩ Linear Potentiometer | RV1 | 1 | |
3mm Red LED | D1 - D10 | 10 | |
2.54mm Switch | SW1 | 1 | |
PP3 Connector | - | 1 |
PCB
Construction Tips
Electronics Construction Guide
To learn more about how to solder electronic components, download the Electronics Construction Manual free using the button below
Component Order
Solder the components in this order to keep things simple
- Resistors
- IC Sockets
- Capacitors
- LEDs
- Switches
- Potentiometers
- Wires
Watch out for the PP3 connector!
- Make sure the red wire is connected to VCC (sometimes V+)
- Make sure the black wire is connected to 0V (sometimes GND)
Double-check your components BEFORE soldering!
- MitchElectronics kits use double-sided PCBs with plated through-holes
- This makes the PCBs extremely strong
- It also makes desoldering very hard, so be sure components are inserted correctly
Final Thoughts
You can use different valued components!
- Feeling brave? Hack the PCB and connect multiple 4017 kits together to make even longer chains!