CAPACITOR
A capacitor also called condenser is a passive two-terminal electrical component which stores energy in an electric field by a layer of insulating film. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric (insulator). Capacitors used as parts of electrical systems, for example, consist of metal foils separated.
When there is a potential difference (voltage) across the conductors, a static electric field develops across the dielectric, causing positive charge to collect on one plate and negative charge on the other plate. Energy is stored in the electrostatic field. An ideal capacitor is has a single constant value, capacitance, measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them.
The capacitance is greatest when there is a narrow separation between large areas of conductor; hence capacitor conductors are often called "plates," referring to an early means of construction. In practice, the dielectric between the plates passes a small amount of leakage current and also has an electric field strength limit, resulting in a breakdown voltage, while the conductors and leads introduce an undesired inductance and resistance.
Capacitors are widely used in electronic circuits for blocking direct current while allowing alternating current to pass, in filter networks, for smoothing the output of power supplies, in the resonant circuits that tune radios to particular frequencies and for many other purposes.
| Circuit Number | Capacitance (uF) | Resistance (Ohms) | Observed Time (ms) |
| 1 | 100 (uF) | 1000 Ohms | 500 ms |
| 2 | 100 (uF) | 100 Ohms | 45 ms |
| 3 | 100 (uF) | 470 Ohms | 250 ms |
The current flow and charge time are directly proportional to each other.
RELAYS
A relay is a device which switches on a high amperage device using a low amperage one. This low amperage circuit is called a control circuit. The control circuit has a coil of wire that creates a magnetic field around it when the circuit is powered and earthed. The switching circuit (higher amperage circuit) will has a set point of contacts that are switched on and off by having the magnetic field pull (attract) the points over to connect with another set of points.
The control circuit of the relay usually gets its power from the battery. It will also have a switch that will turn on and off the circuit. This switch can either be on the positive side of the circuit or the negative side of the circuit. The circuit can be switched by either a switch, a sensor with a switch inside it, or an ECU (electronic control unit) that does the switching based on a logic circuit.
The switching circuit (high amp circuit) also gets its power from the battery and this circuit is connected to the component.
TRANSISTOR
It’s a device which is used to amplify and switch electric signals. It uses a small amount of current to open the gate for a high current and voltage flow. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current flow in the other pair of terminals. Semi-conductor is a device which has either extra electrons or extra protons. There are 2 types of transistors NPN and PNP. NPN, as the name suggest has 2 layers of –vely charged semi-conductor and 1 layer of +vely charged semi-conductor. The PNP has 2 +vely charged and 1 –vely charged.
MOSFETS
Metal–oxide–semiconductor field-effect transistor
It is a transistor used for amplifying or switching electronic signals. The basic principle of this kind of transistor was first proposed by Julius Edgar Lilienfeld in 1925. In MOSFETs, a voltage on the oxide-insulated gate electrode can induce a conducting channel between the two other contacts called source and drain. The channel can be of n-type or p-type.
