Speed on display: The mechanism behind digital speedometers on bikes

The digital wave has swept across almost all the aspects of our lives, and transport is also no exception. The two-wheeler technology has significantly advanced with digital speedometers. Moreover, the increased trend of purchasing a two-wheeler has even fanned further advancements in bike instruments. The security can be easily ensured with bike insurance from Zurich Kotak General Insurance. This is essential as you have to mandatorily maintain a valid two-wheeler insurance if you maintain a bike.

Bike speed display

It is very essential to keep a close monitor on the current speed rate of the concerned bike, to avoid any mishaps. The spinning wheels of the bike remain connected with the easy pointer display on the handle. It is quite a tricky concept but nonetheless, manageable.

Digital speedometer display mechanism

The digital speedometer always displays the speed of the bike in kmph. It is a uniquely designed opaque disc, efficiently mounted upon the spindle that remains attached to the front wheel. The periphery of this disc bears ten equidistant holes. On one side of this disc, there remains an LED and on the other side in sync with the IR LED along with a special phototransistor.

Digital speedometer circuit

The phototransistor conducts if any hole appears between the phototransistor and the IR LED. So, the voltage at the phototransistor collector and the inverting unit of the special LM324 becomes low while the output of this LM324 goes high.

The rotation of this speedometer cable tends to become a square-wave pulse because of the LM324 pulse. The frequency of this particular wave type is proportional to the bike speed.

Testing

With a specific resolution of 1 kmph, a standard speedometer can measure up to 99 kmph. However, this range can be further enhanced up to 999 kmph, if another additional stage is added with each IC of 7490, 74175, and 7447 along with a 7-segment display. The necessary voltage supply is acquired from the 12V power supply of the concerned two-wheeler.

The wheel circumference is taken into consideration while making this calculation and alignment.

Speedometer mechanism

A standard digital speedometer effectively works by utilising a special sensor for measuring the rotation of the bike wheels in motion for efficiently converting it into a speed reading. The special sensor sends the necessary signals to the electronic control of the vehicle or the ECU. It processes the relevant information and in turn, displays the current speed on the vehicle dashboard.

Components of a digital speedometer

A digital speedometer is composed of LCD, electric circuit and magnetic sensors. These magnets are connected to the outer shaft through dual magnetic sensors on both sides. A specific electrical pulse is generated within the circuit every time the magnet crosses those sensors.

Summarising:

We can briefly understand the basic mechanism of the digital speedometer displays of modern-day bikes. However, you must ensure to maintain valid bike insurance irrespective of the model or mechanism of the concerned two-wheeler.

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