The purpose of this research is to design and realization of an electronic circuitthat is able to control the water level in a tank. The circuit shows a tank water level in decimal numbers and controls the volume of water in the tank. So that when th
e level of water drops below a specific value that is preselected using a probe, the pump water works. When the water level reaches to another limit value, the pump stops working.We used for water level control a container which is made by transparent glass with volume of 15 L. the container is divided in nine levels. In addition to this purpose, because of large applications for realized electronic board, The circuit measures the speed of rotation of DC motorsin a wide range (0001 to 9999) cycles during a chosen period of time that ranges from 1 sec to 110 sec and display the speed of rotation in decimal numbers that appears on four displays. Moreover, the circuit contains a switch reset/start, for display clear and restart of measurement.
This study was carried out on samples of tap water, for several values of distance between the probes, and power supply. We found a quick response in showing levels and high efficiency in performance. We measured the number of special motor cycles for several values of the power supply during 30 s and 60 s, and the relation between the number of cycles and applied voltagewas drawingwe found it a linear relation.
Induction motors are the most widely used electrical motors due to their reliability,
low cost and robustness. However, induction motors do not inherently have the capability
of variable speed operation. Due to this reason, earlier dc motors were a
pplied in most of
the electrical drives. But the recent developments in speed control methods of the induction
motor have led to their large scale use in almost all electrical drives.
Out of the several methods of speed control of an induction such as pole changing,
frequency variation, variable rotor resistance, variable stator voltage, constant V/f control,
slip recovery method etc, the closed loop constant V/f speed control method is most widely
used. In this method, the V/f ratio is kept constant which in turn maintains the magnetizing
flux constant so that the maximum torque remains unchanged. Thus, the motor is
completely utilized in this method.
This research aims to study the effect of rotation speed and armature
current density or load current of micro dc motors on the commutation
current, especially on the final phase where electrical spark occurs on the
motor collector. A relationship
of how electrical spark time and density or
energy is related to rotation speed and armature current density, will be
deduced. This research was supported by special laboratory experiments,
and ended up with useful scientific results.
