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
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.
The present circuit of a motorcycle electronic turn signal beeper has been specifically 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.
R1, R2, R3 = 10K,
R4 = 33K,
T1 = D1351,
T2 = BC547,
T3 = BC557,
C1, C2 = 33uF/25V
D1 = 1n4007,
COIL = Buzzer coil
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.