Two Cheap Christmas LED flasher circuits is controlled by audio

This Christmas LED flasher circuit project controlled by audio is designed to meet the needs of create particular project. In order to get the Christmas and New Year. I suggest the project get to the upcoming festival.

These project is an LED chaser that is controlled by the voice signal. This principle the led run is not fixed or not of course, is a sparkling running light. The sound from the microphone or input signal.

External structure, we used a tree Christmas on the PCB. And the below section is the equipment PCB assembly, use a built-in battery makes, easy move to display it anywhere convenient.

Small Christmas LED flasher circuit with sound

The small Christmas LED flasher circuit is small and easy and cheaper than this circuit. It suitable for beginner.

How it works

In Figure 1 is the Schematic diagram of this project. First the LED display section, there are IC1- CD4093 as main, inside IC have4 sets of the same integrated circuit. In circuit will be separated as IC1/1, IC1/2, IC1/3, IC1/4 each section of IC will works with more resistors and capacitors. To signal generator to make the LEDs flash.

Figure 1 The schematic diagram

-IC1/1 worked with C1, R1 and C2 to make the LED2 and LED3 flashes.
-IC1/2 worked with C3, R2 and C4 to make the LED4 and LED5 flashes.
-IC1/3 worked with C5, R3 and C6 to make the LED6 and LED7 flashes.
-IC1/4 worked with C7, R4 and C8 to make the LED8 and LED9 flashes.

The LED1 flashes for the timing of the IC.
The second, in sound section, we use melody generator IC2-UM66 is IC packages, inside will have audio recording music. Which we can choose the music for many songs as you likes as table 1. For the prototype, use number UM66T01L / S, which is a Christmas song fit.

Table 1 more number of UM66T sereis

The IC will has 3 lead, As follows:
– V+ is the power supply lead , has R9 to limit current
– the ground lead to negative battery.
– output lead to the piezo speaker to emit the music sound.

Recommended: 1.5V 4 LEDs Flasher circuit using transistors

How to build

This project we use PCB layout as Figure 2 and assemble all parts as Figure 3 the components layout

Figure 2 the PCB layout real size

Figure 3 the components layout

The parts you will need

IC1: CD4093__schmitt trigger nand gate
IC2: UM66T___Melody generator
C1, C3, C5, C7: 0.1uF 50V___Ceramic capacitors
C2,C4,C6,C8,C9: 22uF 16V___Electrolytic capacitors
LED1-LED9: LED as you need
R1,R2,R3,R4: 10M
R5: 15K
PZ1: Piezo speaker
B1: 1.5Vx4 battery = 6V supply.

16 LED Christmas  Running light circuit

Then see the second circuit. When no audio LED will still does not lit. But once the sound through the microphone into, may be music or voice. The circuit will drive the LED to running switch back and forth, looking sparkling striking for a special gift this year.

How this circuit works

At the input of circuit has to get two sound signals are first get the audio signal from the condenser microphone, and second the audio signal from line input. The audio signal that enter through the condenser micro phone is going through the IC-1A(CD4069). To amplifier by By entering the middle of the C3 pin jack line input.

The audio signal input through the line input signal is quite strong. So do not need amplify this signal, that we design the circuit has 2 input to the convenience of the user in the selected input signal.

For example, some people may be using Micro phone’s signal. That have unclear signals. Makes flashing of the LED look not satisfactory.

You can use the sound signal for speaker wire to entered into the line input come to pass a IC-1B(CD4069), then apply to both diode(1N4148) D1 and D2 is rectifier to selected the negative signal into the IC(CD4069). Next, the signal from the IC will be positive voltage that has changing as the sound signal input.

This some the positive voltage that has to change will flow to pass the diode D4 and a potentiometer VR2(250K). Then It flows to a VCO circuit(Voltage Control Oscillator). It uses the voltage to controls the oscillated generation, which it uses  IC1(CD4069)-1F and IC1-1E. We use both parts to join together with the components R, C is the VCO circuit.

In the production of a waveform depends on the positive voltage across VR2 entered into pin 14, which is a pin of the clock signal of IC2-CD4017 act count number 1 to 10 but However. In this circuit, we design counting the number of 1 to 8 only. The output of IC2(CD4017) will connect to pin 3 of TR3(2SC945) to TR10(2SC945) to act as the driver for the LED display.

The positive signal from IC the other part is entered through D3, and to IC1(CD4069)-1D then into pin B of TR1(2SC945) at pin C of TR1(2SA733). It connects with the negative voltage and pic C pass both R8 and R9 are connected to pin cathode LED to control entering the negative voltage into LED

To conclude, If the input signal through with the correct fit, pin cathode of? LED will connect with the negative voltage by TR1(2SA733) control and IC-2. It also drives the transistors TR3(2SC945), TR10(2SC945) works as counting. The 1 to 8 our light running so run on not sure stye follow by the sound input.

Keep reading: LED Chaser circuit

Let’s build this circuit

You can see the PCB layout in figure 2 for build this projects