Last Updated on June 30, 2025
Heart Shape LED Flasher circuit using Timer IC 555 is one of those simple and cute circuit that is not only makes a great gift or DIY decoration but also teaches us the basics of LED blinking using the popular NE555 timer IC. So that i wanted to share this circuit design because it’s fun, beginner friendly, and visually interesting, especially for special occasions like Valentine’s Day or for tech gifting ideas.
This Heart Shape LED Flasher Circuit blinks a set of LEDs arranged in a heart pattern, here i used only 8 Red LEDs, you can use upto 20, if you want to add even more then you need to upgrade transistor (Q1) to handle current flow. The blinking effect is controlled using a 555 timer in astable mode, which continuously turns the LEDs ON and OFF by driving a BC547 NPN transistor.
Circuit Diagram
Components Required
| Component | Value | Quantity |
|---|---|---|
| NE555 Timer IC | NE555P | 1 |
| NPN Transistor | BC547 | 1 |
| Capacitor | 100µF / 25V | 1 |
| Resistor | 2.2kΩ | 1 |
| Resistor | 330Ω / 1W | 1 |
| LED | Red (5mm) | 10 |
| Battery | 9V | 1 |
| Breadboard / PCB | – | 1 |
| Connecting Wires | – | as needed |
Working Video
Construction & Working
Here Timer IC 555 Configured in Astable Multivibrator mode with Open Discharge (Pin 7) and Openu Control Voltage (Pin 5). Output from this configuration is continuous square wave on pin. Here capacitor C1 (100μF/25V) and the Resistor R1 (2.2KΩ) set the timing intervals, by changing value of these components you can get different range of output frequency (Blink speed).
To deliver Vcc and High current to LEDs, here i used transistor BC547 (NPN) at the output stage. Heart shaped LEDs connected in parallel attached to the emitter terminal of output transistor through 330Ω Resistor. You can use power supply from 5V to 9V to this circuit.
The Timer IC 555 gives square wave output that toggles HIGH and LOW. During the HIGH signal, transistor gets turn ON and makes current flow to the LEDs and lights up. During the LOW signal, transistor gets turn OFF and disconnects LEDs from the power supply so they go dark (off). This cycle repeats as long as power is applied. It makes fading heart beat effect.
Prototype
