Red Blue Police Light Flasher Circuit

This article shows you how to build a flashing LED light like police cars use.

It uses two common chips called IC 555.

These chips are set to different speeds.

They are connected to two sets of LEDs wired in a special way antiparallel.

This makes the LEDs in each set flash back and forth creating a cool alternating blinking pattern.

What is a Red Blue Police Light Flasher Circuit:

A Red Blue Police Light Flasher Circuit is an electronic circuit designed to flash red and blue lights alternately, mimicking the visual pattern of police lights.

This type of circuit is often used in model police cars, emergency vehicle replicas, or other hobbyist projects to create a simulated police light effect.

The flashing pattern is typically achieved using LEDs of red and blue colors.

Circuit construction details:

Parts List:

Constructions details of above circuit is mentioned below:

• Gather all the required components listed above.
• Ensure that the LEDs you choose are compatible with the power supply and check their voltage and current requirements.
• Place the two 555 ICs on the PCB.
• Connect pins 2 and 6 of both ICs to the positive supply and pins 1 and 8 to the negative supply.
• For each 555 IC, configure them as astable flip flops by connecting a resistor R2 and R3 and a capacitor C2 and C3 in series.
• Connect one end of the resistor to pin 7 and the other end to pin 6.
• Connect the capacitor between pin 6 and pin 2.
• Repeat this setup for the second 555 IC.
• Experiment with different resistor and capacitor values to adjust the flash rate and color switching frequency.
• R3 and C3 will affect the flash rate, while R2 and C2 will influence the frequency of switching colors.
• Establish two groups of LEDs.
• Connect one group to the output pin 3 of the first 555 IC and the other group to the output of the second 555 IC.
• Connect the cathodes of the LEDs to the negative supply.
• Experiment with different numbers and colors of LEDs.
• Ensure that the total current does not exceed the maximum output current of the 555 circuit 200mA.
• Adjust the value of R1 to prevent the LED current from exceeding its maximum limit.
• Connect the power supply to the positive and negative supply of the PCB.
• The circuit is designed to be powered by any 12V supply within the range of 9 to 15V.

Formulas:

The circuit creates a flashing signal for the LEDs using a IC 555 integrated circuit.

Two resistors R1 and R2 and a capacitor C1 control the flashes timing.

The following formula can be used to determine the flashes frequency:

Frequency = 1 / (1.1 * R1 * C1)

where,

• Frequency is in hertz Hz
• R1 is the resistance of resistor R1 in ohms Ω
• C1 is the capacitance of capacitor C1 in Farads F

The following formula can be used to determine the duty cycle of the signal, or the percentage of time the LEDs are on:

Duty Cycle = R2 / (R1 + R2) * 100%

where,

• Duty Cycle is a percentage (%)
• R1 is the resistance of resistor R1 in ohms Ω
• R2 is the resistance of resistor R2 in ohms Ω

Note:

These are only broad formulas that do not account for all of the circuits intricacies.

The computed values may not exactly match the circuits real timing characteristics.

Warning: Caution Regarding Health Impacts

Be cautious about the potential health impacts of flashing lights especially in individuals susceptible to seizures.

Operate the LED police flasher responsibly and be mindful of its impact on those with sensitivities.

With these circuit connections, you can construct a customized red blue police light flasher circuit that provides an engaging visual display.

Conclusion:

Building a red and blue police light flasher circuit for your toy automobile is similar to building a little nightclub!

A IC 555 is a specific kind of chip that you will use to make the red and blue LEDs flash on and off alternately, just like actual police lights.

It is an enjoyable project, but it is best completed with an adults assistance because there are some small components involved.

References

Emergency vehicle lighting