Monday, September 5, 2011

ilyas post 4

Fault finding problem:

When doing a fault finding problem i came across wire point  3 this is what happens when it was cut off.
point 3 The yellow LED keep turning on always.
The pin10 will get 0v and a pin9(signal voltage) is always higher than the pin10. Therefore, the current flows through the yellow LED and pin11(earth) of voltage rail and the yellow LED always turns on.


Heres a video clip i recored after i fixed into the and when i connected it to a car it shows when the car is running lean normal or rich.



Electronics Components 

Zener Diode


A Zener diode is a special kind of diode which allows current to flow in the forward direction same as an ideal diode, but will also permit it to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage, "Zener knee voltage" or "Zener voltage." The device was named after Clarence Zener, who discovered this electrical property.
A Zener diode exhibits almost the same properties, except the device is specially designed so as to have a greatly reduced breakdown voltage, the so-called Zener voltage. By contrast with the conventional device, a reverse-biased Zener diode will exhibit a controlled breakdown and allow the current to keep the voltage across the Zener diode close to the Zener breakdown voltage. For example, a diode with a Zener breakdown voltage of 3.2 V will exhibit a voltage drop of very nearly 3.2 V across a wide range of reverse currents. The Zener diode is therefore ideal for applications such as the generation of a reference voltage (e.g. for an amplifier stage), or as a voltage stabilizer for low-current applications.

Capacitor  


In a way, a capacitor is a little like a battery. Although they work in completely different ways, capacitors and batteries both store electrical energy. It does this by providing ground when there is an open circuit (switch is open). This storage of electrical charge prevents voltage spikes from happening. A capacitor consists of two metal plates very close together.When connected to a battery or a power source electrons flow into the negative plate and charge up the capacitor. This charge still remains when the battery or the power source is removed. The amount of charge a capacitor can store depends on the capacitance of the capacitor (measured in Farads F). Capacitors are also used in circuits to smooth-en out the current flow. This allows for the circuit to have a constant smooth flow of current. 
for more information please visit this to find out how it really works 
http://electronics.howstuffworks.com/capacitor1.htm


Relays

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal (with complete electrical isolation between control and controlled circuits), or where several circuits must be controlled by one signal. 
Relays allow one circuit to switch a second circuit which can be completely separate from the first. For example a low voltage battery circuit can use a relay to switch a 230V AC mains circuit. There is no electrical connection inside the relay between the two circuits, the link is magnetic and mechanical.

http://www.kpsec.freeuk.com/components/relay.htm

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

Hybrid electrical vehicle 


What makes a hybrid car so fuel-efficient? It's quite simple — they only burn gasoline when needed. That's because, as the term implies, hybrid cars have two different power plants under the hood: a powerful electric motor and a conventional gasoline engine. The electric motor, powered by a stack of rechargeable batteries, is the primary workhorse for moving the car during slow-speed driving — such as through a residential neighborhood or in stop-and-go urban traffic.
During coasting and slow-down phases when a driver lightly taps on the brakes, the car's wheels are automatically engaged to an electrical generator. The generator creates an extra "load" to assist the brakes in slowing the car down, but more importantly, it converts the car's mechanical energy back into electricity to recharge the car's batteries.
At higher speeds, such as steady highway cruising, computers automatically switch on the gas-burning engine, which then takes over as the primary driving force of the car. Typically, the small engine is designed with variable valve timing intelligence, or VVT-i, and other advances to ensure that the fuel is burned most efficiently and completely.
But both the electrical motor and gas-powered engine can also operate in conjunction. For example, if more power is needed to merge onto a highway or pass a tractor-trailer truck, the on-board computers will automatically activate the electric motor to provided the needed acceleration boost.
Hybrid proponents say the power combination offers consumers the best of both an electric car and a conventional gas-fueled vehicle. At complete stops — say, in rush-hour highway traffic where most car engines are spent idly wasting fuel — the car isn't using any gas at all. But like a pure-electric car, once a driver steps on the "gas" pedal, the electric engine comes to life and instantly propels the car forward.


Here is a video i presented in class and it shows the new and futur of BMW .
Must Watch Good Video.




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