2-Pin Motorcycle Turn Signal Flasher Indicator Circuit with Beeper

A simple construction procedure of a motorcycle electronic 2 pin turn signal indicator with beeper circuit has been thoroughly explained in this article.

Normally, the electro-mechanical types of turn signal indicators are not reliable due to low consistency and vulnerability to changing weather conditions.

The present design easily withstands the above parameters and more importantly consists of an attached buzzer indication facility.

The inclusion of an audible signal makes it sure that once the required deviating turn is completed by the vehicle; the driver remembers to switch off the unit and save precious battery power

Conventionally a turn signal indicator will require three output terminals for its correct operation. Uniquely the proposed circuit works with just a couple of terminals, and moreover incorporates a built-in buzzer.
Here we explain a simple motorcycle electronic turn signal with beeper circuit.

Video Test Result

Introduction

Also popularly known as “flasher with buzzer,” turn signal actuators are indispensable piece of devices for every vehicle.

The device is particularly used for switching or flashing the side indicator lights (left or right) of a vehicle while making a turn or a deviation from its normal path.

Basically the flashing of the lamps acts like a warning signal and makes it easier for the other vehicles to identify the track of the indicating vehicle.

This averts a possible collision and misunderstanding between vehicles. The device thus specifically helps in avoiding accidents and mishaps.

Nowadays many folks prefer the above devices accompanied with an audio indication like a buzzer or a beeper which may produce a rhythmic note with the light switching.

This facility proves to be useful in two ways, first: it assures the driver regarding the perfect working of the entire system and second: when the necessary deviating move or a turn is completed, the audio note keeps reminding the driver that the unit is still ON and needs to be switched off, thus saving precious battery power and false indications.

Cheapest 2-pin Flasher Buzzer for 2 Wheelers

The present circuit of a motorcycle electronic turn signal flasher with beeper has been exclusively designed by me and tested thoroughly, in fact I have already sold more than 90,000 pieces of them in the market and the demand keeps growing. The circuit described here is very unique because of the following reasons:

· Its 2-pin design makes it compatible with almost all 2 wheeler wiring system.

· Since it is electronic and solid-state becomes very long lasting and weather proof.

· A built-in high quality piezo buzzer makes it a better choice with the folks.

Parts List

• R1, R2, R3 = 10K,R4 = 33K,T1 = D1351,
• T2 = BC547,
• T3 = BC557,
• C1, C2 = 33uF/25V
• D1 = 1n4007,
• COIL = Buzzer coil

Circuit Operation

Let’s try to understand its functioning with the following points:

From the circuit shown alongside we see that the whole circuit is built around just three inexpensive active components T1/T2 and T3.

A few other passive components in the form of resistors and capacitors are used to initiate the flashing action and sustain it as long as power remains switched ON to the circuit.

When power is first switched ON, capacitor C1 slowly charges via R1.

The moment it reaches its full charge, T3 is able to conduct and provides some sort of an initial biasing voltage to T1/T2.

T1/T2 partially conduct and in the process turns ON T3 much harder through R2, because now T3 receives full biasing through R2, T1 and the lamps switch ON.

The lamp now receives full power through T1/T2 and ignites.

But around this time C1 almost instantly discharges through R1, T1/T2 and the lamps, blocking the emitter of T3.

T3 immediately stops conducting, so does T1/T2 and the lamp shuts-off influencing a fresh cycle to begin. The lamps thus start flashing.

D1 and C2 are placed to filter out any AC component or spike that may be present in the auto electrical while it’s in motion.

The circuit of this motorcycle electronic turn signal beeper also incorporates a small yet powerful buzzer circuit connected in parallel to the supply line.

During the flashing process, at the instants when the lamp is turned ON the buzzer stops sounding and vice versa. This happens because the lamps suck out almost all the power from the circuit and the buzzer is not able to receive the required voltage and is able to beep only when the lamp shuts off in between.

2-pin Flasher using a Single IC 4093

A single gate of the Schmitt Nand IC 4093 works like a 1Hz free-running-multivibrator and the remaining three gates in parallel function like a buffer stage to turn the BUZ1 1 power mosfet ON/OFF. Zener diode shields the entire flasher circuit from voltage transients.

At power switch on, the status of the gates are such that the mosfet remains switched off and C1 starts charging through D1, R2 and the automotive lamp. Throughout this period, C2 gets charged via RI, finally turning ON the multivibrator, and switching the mosfet and the series lamp ON.

The Power to the 2 pin flasher circuit is delivered throughout this time period is through the charged C1. Capacitor C2 now begins discharging by means of R1; the opposite course of action starts transpiring, the mosfet is now turned off, making it possible for C1 to begin charging up again so that the cycle keeps repeating.

About Swagatam

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials.
If you have any circuit related query, you may interact through comments, I'll be most happy to help!