REFRIGRATED CENTRIFUGE DENGAN PARAMETER TIMER DAN MODE PRESET

Refrigerated centrifuge is a tool used to separate compounds that have different
molecular weights by utilizing centrifugal force and cold temperatures. In general,
refrigerated centrifuges still have drawbacks, namely the absence of automatic
features. This automatic feature or can be called preset mode is very much needed
because it can simplify the work of laboratory users, namely laboratory users only
select the desired preset without setting the timer and speed first. In this study,
modifications of the refrigrated centrifuge with timer parameters and preset modes
were carried out using a 20x4 character LCD, requiring an L298N motor driver to
control PWM and motor speed, then Arduino itself as a processor whose data will
be displayed on the LCD. In this modification of the tool the author optimizes the
motor rotation by setting a speed of 1500 - 4000 RPM and a preset mode which
consists of 7 presets and time settings ranging from 0 - 60 minutes, for settings
using the select, start, and reset buttons. In this tool, the largest error value is
found in preset 1 (2000 RPM) which is 5.1%. And on the timer measurement, the
largest error value is found in preset 1 (5 minutes) which is 0.58%. It can be
concluded that the refrigerated centrifuge can be used properly because the error
in the speed and timer parameters in the preset mode is still less than the tolerance
value limit, which is ±10%