Electro-Magnet Case
Electro-magnet
It is easy to build an electromagnet. There are 2 things need to prepare for electromagnet that is insulated copper wire and an iron core. All you need to do is wrap some insulated copper wire around an iron core. In this assignment, the turn of copper wire is around 1500. When an electric current flows in a wire it creates a magnetic field around the wire. Unlike bar magnets, which are permanent magnets. The magnetism of the electromagnets can be turned on and off just by on or off the power supply. By adding more turns to the coil and increase the current flowing through the coil to make the electromagnet stronger.
Photo detector and photodiode
An infrared light emitting diode (IR LED) is a device that creates light with a wavelength just slightly longer than what the human eye can see. These devices emit light in the near infrared range, meaning that they produce light that is closer to the visible light spectrum than microwaves, which are the next longest wavelength.
The function of a photo detector is to detect the intensity of infrared light and take that information and transfer it to a format usable by other products. A photo detector transfers the information into electrical energy. Photo detectors are sensors of light or other electromagnetic energy. A photodetector consists of a photodiode and accompanying circuitry that produces a current in response to light. Photo detector and photodiode act like a feedback in this experiment.
This circuit works by comparing the signal from the sensors with the first op-amp and send out a voltage proportional to the difference or “error”. The compensation network acts like a high pass filter which is the error signal sent through. This is required to stabilize the control loop. If without a feedback or control system, the load will stick to the electromagnetic due to the system being unstable.