Review retrieval 3 º ESO

Types of levers: First grade: R, PA, F. Second grade: PA, R, F. Third grade: PA, F, R. Worm, use transmitting rotary motion between two shafts that form an angle of 90 degrees (always input and output gear). Description: Has a single tooth-shaped wire thread. The gear is a toothed wheel. Each time a turn just a cog goes with it. Features: The relations of transmission of motion through right angles, high cost and mov. without noise. pinion-rack system: This is a straight-tooth pinion, a rack engarnazado. When the pinion turns, the rack moves with mov. rectilinear. This mechanism allows transforming tambn mov. rectilinear of the rack in a mov. Circular of the pinion, ie in a mov. reversible.Screw-nut system: Consists of a screw and a nut whose inner diameter matches the diameter of the screw. If the screw rotates and maintains fixed the orientation of the nut, this is moving mov. rectilinearly by the threaded shaft, and vice versa. Biela-crank: This consists of a handle and a bar (rod). By turning the wheel, the crank transmits mov. circular rod, which experiences a back and forth (tambn works in reverse). Crankshaft: If you put a series of rods in a single angled shaft, each shaft elbows serves as a crank, and the set is called a crank. Transforms the mov. rotation of a shaft in the mov. alternative of step of the different rods. It can also convert mov rods swaying in a mov. shaft.Cam: It’s a wheel with a projection that pushes a follower in its wake. The cam converts mov, rotation of the wheel in a mov. alternative linear follower, which runs along the cam prfil when this tour. Excenter: Consists of a wheel whose rotational axis does not coincide with the center of the circle. Transforms the mov. rotation of the wheel in a mov. alternative linear rod. Eccentricity is called the distance between the center of the circle and the axis of rotation of the eCentre. Electrical quantities: Quantity of Electricity: Coulomb (C). Current intensity: Ah (as measured by the ammeter) 1A = 1C/1segundo. Resistance: Ohm (measured with the Ohmmeter). Voltage: Volts (V). Ohm’s Law: I = V / R, V = I * R, R = V / I. Electrical Voltage: V * I = watts, P = (I * R) * I = I2* R, K = V * I * t = W * h current (features): Tensions low, low intensity, thin wire, electrons flow in one direction and intensity constant in time. Alternating Current: Tensions high the current flows in both directions, the intensity is not constant over time, changes continuously.

Tolerance is the difference between the value of real or nominal resistor. It can be defined as the range between the max values. or min. a resistor. Potentiometers: In the variable resistors can change its value in ohms using the cursor. It is used to adjust the volume, brightness of audiovisual devices, …LDR: This is the resistance that varies with the amount of light they receive (+ light, – resistance). Thermistor: NTC (+ t ª, – R) PTC (+ t ª, + R). Diode is an electronic component made of mat. semiconductor that only allows the passage of electric current in one direction. An LED is a diode that emits light when current passes by. The limit switches are a type of buttons that are operated by a lever pushed porr an item in motion. Normalmete may be open (NO) or closed (NC). The switches direct current through one path or another. Thecapacitor is a component capable of storing electric charge comprising 2 flat and parallel metal plates separated by an insulator. If the plates are connected to the electric poles No rightholder belongs the same load of each of opposite sign. When you disconnect the generator plates can not have + conddensador cargo and acts as a generator. The transistor is em important component electric + and + used. This consists of 3 layers of mat. semiconductor where we put 3 terminals and then encapsulate for k can be mounted on a circuit. PNP: This consists of the collector (P), base (N) and issuer (P). NPN: C (N), B (P) and E (N). Database: Elements: The record (row) conntiene all information on the various aspects of the same person or subject. The field (column) are the different categories in which sse divides the contents of a register. The database is the collection of data collected and stored according to specific criteria. The table is the obj. a basic foundation. While there may be several tables deistintas in one database, each can be considered the base + elementary. The form contains the same data as a table, but in a way + distributed is orderly and easy to use. Tri-fold change or enter all the information you want. TheConsultation is the process + powerful to interrogate the database. With them we have organized and Disponibe the data we use to + frequency. The report is a summary containing one or + tables. The realization of reports submitted on paper will allow the data we have stored in tables organized.