Categories: Fun Circuits

LED Flashing Heart

This is the LED flashing circuit, since the shape used in this circuit was hearth shape, then we call it LED flashing heart circuit. The circuit is quite simple, low cost, easy to built. Alternatively, you could be create another shape, not just heart shape.

Schematic diagram:

LED Flashing Heart Circuit Diagram

Component list:

Resistors
R1, R2 470 ohm, 1/2-watt
R3-R5 100 ohm, 3-watt
R6-R8 1000 ohm, 1.4-watt
R9 5000 ohm potentiometer
Capacitors
C1, C2 100uF, 16 volts, electrolytic radial
Semiconductors
IC1 4047, low power monostable/astable multivibrator
Q1-Q3 2n3643 NPN transistor or equivalent
Diodes
LED1-LED84 yellow light-emitting diode
LED85-LED126 red light-emitting diode
LED127-LED142 green light-emitting diode
Other components
PS1 12VDC @ 500mA wall transformer
Miscellaneous: Jumper wire, solder, printed circuit board,
drill and bits,14 pin I.C. socket, and a frame or case.

PCB layout:

Component placement:

Once power has been applied to the circuit, the Red LEDs should all be flashing on and off together. The Yellow LEDs should be flashing on and off, but only every other Yellow LED should be on at one time. The Green LEDs will stay on at all times. The flash rate can be adjusted by turning R9. Connections for a fixed value resistor for R9 are provided on the board layout if preferred.To dress up the project, a favorite photograph can be placed in the heart, and a frame can be made to fit the circuit board.

Complete explanation, please visit this page

circuit diagram

View Comments

  • Hello! I know it's a bit late but I found this project and wanted to give it a try.

    I have already built it up and it works... but not properly.... The green leds stay on, the red ones blink but only some of the yellow blink alternatively, I mean, half of the yellow leds light up but the others don't. All the connectios are well soldered because I've double-checked it. So, for those who wander (tom and jajaja), it works and it is worth the effort and the money. I had fun making it and although is not working I'm proud of this project. I'm sure that looking at the schematics at the end I will find a solution, but if anyone could help me it would be amazing!

    So,if somenone can read this and want an image or a video just send a message!

    Hope I can get an anwser!

    Alexis (Spain)

  • hola puedo imprimir directamente el circuito de la figura 2 y plancharlo en la baquelita. o nececito el efecto de espejo

  • or course it will work because the circuit already tested. the negative pin of LEDs should be the pin which connected to the ground.. :)

Recent Posts

Power Amplifier 45W Using uPC 1230 + Pre Amp Head uPC 1032

This is the circuit diagram of power amplifier 45W using power uPC 1230 as the…

55 years ago

Horn and Lamp Flasher Circuit for Car Reversing Gear Mode

The Horn Circuit This is a basic circuit of car horn and lamp flasher that…

55 years ago

Alarm Circuit for Drinking Water

This is the circuit diagram of drinking water alarm based a small water sensor by…

55 years ago

200W MOSFET Amplifier based IRFP250N

Here is the 200W MOSFET amplifier powered based on four piece of IRFP250N, they are…

55 years ago

300W RMS Stereo Power Amplifier based IC TDA7294

This is the 300W RMS stereo power amplifier circuit project. This amplifier is based four…

55 years ago

Stereo Tone Control with Line In + Microphone Mixer

This is an active stereo tone control circuit using very well known op-amp IC of…

55 years ago