A Light Emitting Diode (LED), a semiconductor-based light emitter, is commonly referred to as an LED Blinking. As diodes permit the flow of current in one direction while blocking it in the other, they safeguard the circuit’s components from harm. LEDs perform a similar function but also emit a small amount of light when current flows through them, serving as a visual indicator to ordinary individuals that the circuit is operational. LEDs find versatile applications, primarily in visual indications within electrical devices, measurement and interaction with processes, displaying images on television screens or advertising billboards, and more.
We have presented two LED blinking circuits below. The first one involves dancing bi-color LEDs, where two distinct-color LEDs operate sequentially. In the second circuit, the LEDs blink at regular intervals.
- Dancing Bi – Color LED Circuit:
- Block Diagram of Bi-Color LED Circuit:
- Bi-Color LED Dancing Lights Circuit Diagram:
- LED Flasher Circuit:
- Block Diagram of LED Flasher Circuit:
- LED Flasher Circuit Diagram:
- LED Blinking Circuits Applications:
Dancing Bi – Color LED Circuit:
Typically, we employ low-voltage bulbs for the dancing bulb effect. This circuit is primarily employed during events, in decorative items, or on visual indication signboards, among other applications. In this particular project, we utilize bi-color LEDs to achieve a sequential running light effect.
Block Diagram of Bi-Color LED Circuit:
A timer is employed to establish the specific sequencing rate for the bi-color LED panel. The CD4017 functions as a decade counter, responsible for managing the timing and controlling the LED’s activation and deactivation in accordance with the predetermined time intervals.
Main Components in this Circuit:
CD4017: The CD4017 is a decade counter with 16 pins but features only 10 output pins. Clock pulses serve as the triggers for the CD4017. Its primary function as a decade counter can be summarized as follows: Upon receiving a clock pulse input, it sets one output pin to a high state during the first clock pulse while keeping the others low. Subsequently, for each subsequent clock pulse, another output pin is raised to a high state, and the remaining pins are set low, following this pattern. The duration of the high state on an output pin is determined by the pulse width. The CD4017 finds application in various scenarios where a counter is needed.
Bi-Color LED Dancing Lights Circuit Diagram:
CD4017 clock pulses from output pins timing diagram is shown below:
Bi-Color LED Dancing Lights Circuit Diagram:
Circuit Diagram Explanation:
- The counter should be connected to the Bi-color LED as illustrated in the schematic. The anode of the first bicolor LED is connected to the anode of the second bicolor LED of the tenth bicolor LED, and the remaining LEDs are connected in the same way, with the exception that the second anode of the first bicolor LED is connected to the CD4017’s reset pin. The cathode of all bicolor LEDs is grounded.
- The 555 timer in astable multivibrator mode and the decade counter CD4017 are responsible for the circuit’s principal operation; the 555 timer generates a low frequency clock pulse and feeds it to the decade counter, which controls the LEDs’ sequential operation.
- The resistance of a variable resistor can be changed, changing the pulse width. The time duration for running the LEDs will change if the pulse width is modified. The LEDs can be turned on and off quickly or slowly. The variable resistor can change the running speed. For continuous lighting, the first anode of the 10th bicolor LED is connected to the reset pin of the decoding counter.
LED Flasher Circuit:
LED Flasher is a simple circuit which will blink the LEDs in regular time period. This circuit can be used for decoration purpose or can be used for a signaling purpose and many more.
Block Diagram of LED Flasher Circuit:
The 555 timer is used to generate the PWM signal which will cause the LEDs to blink. The speed of the blinking by LED is determined by the potentiometer connected to the 555 timer. The PNP transistor is used to flash or blinks the LEDs.
LED Flasher Circuit Diagram:
- The 555 timer is made to be configured as a astable multivibrator. The potentiometer which is connected to the timer should be preset and also to adjust the blinking or flashing speed of the LEDs.
- In this circuit, bicolor LEDs are utilised and are linked as indicated in the design. The output of the 555 timer is passed to the transistor, which functions as an inverter, resulting in the PWM signal. Transistors and LEDs will turn on when the pulse generated by 555 timers is low. When the transistor’s input is high, the transistor is turned off, and the LEDs are turned off. Every pulse width signal cycle, the LEDs will turn on and off. The LEDs will flash as a result of this technique.
LED Blinking Circuits Applications:
- Dancing LED circuit can be used for any visual sign indication in any highways or it can be used in advertisement hoarding also.
- LED blinking circuit can be used in signaling purpose (It can be used as signal for help, if you are in danger)
- LED blinking circuit can be used as flashing beacon.
- LED blinking circuit can be used as vehicle indicator when it is broke down in the middle of the road. It can be used in operation theaters or offices as an indication that you are engaged in work.
- There are lots of applications with these two circuits.