Red Blue Police Light Flasher Circuit

This article teaches you how to build a flashing LED light for 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.

Usually red and blue LEDs are used to create the flashing pattern.

Circuit Building:

Parts List:

Constructions details of above circuit is mentioned below:

• Assemble all the components as mentioned in the above circuit diagram.
• Verify the voltage and current requirements of the LEDs you select to make sure they work with the power source.
• On the PCB arrange the two 555 ICs.
• Attach pins 1 to GND pin 8 to the positive supply and connect pins 2 and 6 to both ICs.
• 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.
• Add the capacitor by connecting pins 6 and 2.
• For the second 555 IC2 repeat these steps.
• To modify the flash rate and color switching frequency try changing the values of the resistor and capacitor.
• While R2 and C2 will effect the frequency of color changes R3 and C3 will affect the flash rate.
• Assemble two LED categories.
• Wire one group to the 555 IC1s output pin 3 and the other group to the second IC2s output.
• Connect the LEDs cathodes to the negative power source.
• Try adjusting the quantity and color of the LEDs.
• Make sure the overall current stays below the 555 circuits 200mA maximum output current.
• To keep the LED current from going beyond its maximum limit change the value of R1.
• Connect the power source to the PCBs positive and negative supplies.
• The circuit is powered by any 12V supply that falls between 9 and 15V.

Formulas:

Below are following formulas for Red Blue Police Light Flasher Circuit:

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 flashing timing.

The following formula is used to calculate 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

Calculating the duty cycle of the signal and the percentage of time the LEDs flash is carried out using the following formula:

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:

The complex design of the circuits is not taken seriously by these basic formulas.

The calculated values could not exactly match the circuit’s actual timing and properties.

Warning: Caution Regarding Health Impacts:

Be aware of the possible negative effects flashing lights may have on your health particularly if you are at risk for strokes.

Use the LED police flasher sensibly and consider how it may affect people who are sensitive.

One can create a personalized red -blue police light flasher circuit with these circuit connections which offers an eye-catching visual display.

Conclusion:

Constructing a circuit for your toy car that flashes red and blue police lights is like constructing a miniature 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 which need expert supervision.

References

Emergency vehicle lighting