Running LED Chaser Circuit With CD 4017 Circuit
Build a running LED chaser circuit using CD4017 IC. Step-by-step guide, components, circuit diagram, working principle, and construction tips included.
What Is a Running LED Chaser Circuit?
A running LED chaser circuit is a circuit using LEDs, in which a series of LEDs are lit up to create a moving or chasing effect. A commonly used application of this sort of circuit is decorative lighting, electronic displays, and learning sequential digital electronics with ICs such as CD4017.
solar emergency light circuit diagram
A Solar Emergency Light Circuit is a set of self-powered lighting installed to supply reliable lighting in case of failure of mains power. It is a solar panel, charge controller, rechargeable battery, and LED lamp with an automatic switching mechanism in that the lights charge during the day and automatically switch on at dusk or a power outage. Solar emergency lights may be miniature, portable (single high-power LED, plus small Li-ion cell) or home-scale, with a battery bank of 12 V, and multiple LEDs. Efficiency, run time, charging speed, and safety depend on the choice of the topology - compact TP4056 + boost driver with a 1S Li-ion pack or a 12 V SLA with a PWM charger or MPPT-based multi-cell Li-ion system. This tutorial not only takes you through the practical circuits, component selections, sizing calculations, assembly hints, and safety measures to enable you to complete a robust Solar Emergency Light Circuit to meet your wishes.
Key Design Choices (Battery Chemistry, Voltage, and Lamp Type)
1S Li-ion (3.7 V):
Compact, high energy density. Needs TP4056 CC–CV charger + boost converter (5–12V). Great for small emergency lamps and portable units.
12 V SLA (Sealed Lead Acid):
Cost-effective, robust, suitable for large home/emergency lights. Heavy but simple charging using PWM chargers.
LiFePO4 (3.2–3.3 V per Cell):
Highly safe, long cycle life, stable. Needs specific LiFePO4 charger/BMS.
LED Types and Drivers
Use high-efficiency LEDs (CREE / Nichia / Samsung) + constant-current drivers for the best performance.
- Small systems: boost converter with current limit.
- 12V systems: series/parallel LED strings with LED driver or resistors.
Core Functional Blocks of the Circuit
Solar Panel & Blocking Diode
Prevents backflow at night. Panel voltage must match charger/battery type.
Charge Controller Options
- TP4056: For 1S Li-ion, simple and cheap.
- PWM Charger: For 12V SLA systems.
- MPPT: Most efficient for multi-cell and LiFePO4.
Battery & Protection
Use BMS, fuses, PTCs, MOSFET switches for safe operation.
Load Output & Switching
- Automatic ON/OFF using LDR + MOSFET.
- Manual switches or remote options.
- PWM dimming for brightness control.
Three Practical DIY Circuit Options
Option A — Small 1S Li-ion System (TP4056 + Boost)
Best for pocket emergency lamps, 1–3W LED.
Core Components:
- 6V solar panel
- TP4056 charger
- 18650 Li-ion battery
- Boost converter (MT3608)
- 1–3W LED + driver
- Schottky diode
Textual Schematic:
Solar Panel → Diode → 5V Regulator → TP4056 IN+
TP4056 BAT+ → Li-ion Cell → Boost Converter → LED Driver → LED
LDR Sensor → MOSFET → LED Control
Option B — 12V SLA with PWM Charger
Best for large home emergency lights.
Core Components:
- 18V solar panel
- PWM charge controller
- 12V 7Ah SLA battery
- MOSFET switching + LDR
Textual Schematic:
Solar Panel → PWM Controller → 12V Battery
Battery → Fuse → MOSFET → LED Driver → LED Array
LDR → Gate of MOSFET
Option C — 2S/3S Li-ion or LiFePO4 + MPPT
Core Components:
- MPPT charge controller
- BMS with balancing
- LiFePO4 battery pack
- Constant-current LED driver
- Microcontroller for smart control
Textual Schematic:
Solar Panel → MPPT → Battery Pack (+BMS)
Battery → Fuse → Constant Current LED Driver → LED Array
MCU / LDR → MOSFET Switch
Sizing Guide (Solar, Battery, LED)
Example calculation for a 10W LED running 4 hours:
- Energy needed = 10W × 4 = 40 Wh
- With margin = ≈ 50 Wh
- Battery (12V): 50 / 12 ≈ 4.17 Ah → choose 7 Ah
- Panel: ≈ 20–30 W (depending on sun hours)
Automatic Dusk/Dawn Switching
- LDR + LM358 comparator
- Microcontroller (ESP/Arduino)
- RTC (DS3231) for timing events
PCB & Wiring Best Practices
- Short, thick wires for battery & solar lines
- Place decoupling capacitors near ICs
- Use fuses & proper insulation
Troubleshooting Common Issues
- Battery not charging → check polarity & PV voltage
- LED flickering → low battery or loose wiring
- TP4056 heating → ensure input is ≈ 5V
Frequently Asked Questions - Running LED Chaser Circuit With CD 4017 Circuit:
What is a running LED chaser circuit?
A circuit that lights LEDs in sequence to create a moving or chasing effect.
Which IC is used for sequencing?
CD4017 decade counter IC controls sequential LED outputs.
What generates the clock pulses?
NE555 timer IC in astable mode generates clock pulses.
How many LEDs can be used?
Up to 10 LEDs per CD4017 IC, connected to Q0–Q9 outputs.
Can I adjust the speed?
Yes, by changing resistor or potentiometer values in 555 timer.
What voltage is required?
Typically 9V DC for 555 and CD4017 ICs.
Do I need current-limiting resistors?
Yes, to protect LEDs from excess current.
Can I use this for decoration?
Yes, ideal for decorative light displays and hobby projects.
Can I chain multiple CD4017 ICs?
Yes, for more than 10 LEDs, cascade CD4017 outputs.
Is this suitable for beginners?
Yes, simple connections make it suitable for electronics beginners.
