Electricity, Electronics and Power Supply System in Railway

[GENERAL POWER SUPPLY] As the current major power distributor in Philippine railways, MERALCO provides _____kV power supply to existing Railway Operators.

[LOGIC GATES] All digital systems can be constructed by only three basic logic gates. These basic gates are called the AND gate, the OR gate, and the ___ gate.

[CURRENT] There are 2 types of current supplied to rolling stocks.

This current seems to be better, but it cannot transmit electricity over long distances. It can only provide power up to about 3 km length for one direction. Many ground equipment is required, but train equipment will be small. Suitable for routes with a large number of trains.

Overhead contact line system (OCLS) is a railway power-supplying method that uses the overhead lines, either an assembly of flexible wires for overhead catenary system (OCS) or long bars of rigid conductors for rigid suspension system, which are situated above the rail tracks to supply electricity to rolling stocks. There are three (3) elements which are the Messenger Wire, Contact Wire, and ______.

A _____ is a device used on electric power systems and telecommunication systems to protect the insulation and conductors of the system from the damaging effects of lightning.

All trains are provided with a battery to provide start up current and for supplying essential circuits, such as emergency lighting, when the line supply fails. The battery is usually connected across the DC control supply circuit. The batteries are grouped to the _______ of the rolling stock.

• Auxiliary Power Supply

• High-Voltage Circuit

• Low-Voltage Circuit

The switching devices required for a low, medium or high voltage electrical circuit. It consists of switching and protection devices such as fuses, circuit breakers, isolators, disconnect switches, relays and other devices that control the flow of electricity.

[ELECTRONICS LOGIC] For the Train Doors Opening Command to function, conditions must be met. Basic conditions are: (1) Speed is at 0 kph, and (2) Mechanical/Friction Brakes are applied. For the command to turn-on, the first logic gate to be introduced to the logic circuit shall be ______.

• AND

• OR

• NOT