A digital speedometer is a device which gives the current speed of a moving object. It can generally be seen in motor vehicles. Like the older models, this device is essential in operating vehicles too, because it gives the person in control of the vehicle/machine awareness of his/her speed so he/she can maintain the correct velocity and avoid crashing with something along the road.
The digital speedometer has a couple of advantages over its ancestor, the analogue speedometer. One of the advantages is that digital ones produce more accurate and reliable readings. This is because digital speedometers use speed sensors which actually reads the vehicle’s moving rate, and then sending results to the speedometer’s microprocessor, which is responsible for the display. Another advantage is that digital speedometers display the speed measurement in numbers, which is a lot more readable than the clock-like display of analogue ones. Drivers suffering from deteriorated vision would surely prefer digital ones as they would no longer need to stare at the pointers and the somehow unclear lines between the digits on the clock-like display.
There had not been a lot of revisions in the digital speedometer. As a matter of fact, only a couple of new parts have been added to make it do its duties properly. As I’ve mentioned in the previous paragraph, it has and should always have a microprocessor that comes with an IC1 and an IC3. The IC1 acts as a mini computer and regulates the voltage of the speedometer while the IC3, a mini drive, gives a lot of special functions like latch, reset functions, and gating signal functions. As for the speedometer’s display, a 2 column LCD mini-monitor which can show up to 16 characters is provided.
Outside the mini-computer system is the IC4 and a detector which measures the rate of the wheels’ rotation. A magnet is attached to a wheel for sensing. It will pass by the detector once in every rotation of the wheels; each rotation is equivalent to a single detection. The detector will then generate pulses depending on the number of detections it has made (the ratio is 1:1). The pulses will then be computed by the IC1, after which the digits indicating the speed (miles or kilometres) per hour will appear on the LCD. An interesting feature has been added to the latest models too, that is, the ability to calculate how far the vehicle has travelled from the last time the engine had been started up to the last time it had stopped.
It is a fact that both the analogue and digital speedometers cannot give the exact rate at which a vehicle runs. The digital speedometer however has the edge over analogue ones in terms of accuracy, as it is the “upgrade” of its predecessor. They may have some differences, but they share a common purpose, that is, to give guidance to the driver for safe driving.