The most basic and crude form of power supply design is the one which uses a single diode and a capacitor. Since a single diode will rectify only one half cycle of the AC signal, this type of configuration requires a large output filter capacitor for compensating the above limitation.

Power System A source of electricity, such as a battery, provides electrical energy in the circuit. Unless the circuit is complete, that is, making a full circle back to the electrical source, no electrons will move. Generally, there is some appliance that uses electricity in the circuit.

DC-DC power supplies allow you to plug in electrical devices into car outlets or similar sources that supply direct current, or DC, power. These power supplies are not the most commonly used, though.

Power Supplies

• Transformer – steps down high voltage AC mains to low voltage AC.
• Rectifier – converts AC to DC, but the DC output is varying.
• Smoothing – smooths the DC from varying greatly to a small ripple.
• Regulator – eliminates ripple by setting DC output to a fixed voltage.

The formula used to determine the AC voltage required from the transformer is as follows:

1. Vdc= Output voltage.
2. Vreg=Voltage drop of the regulator =3v.
3. Vrec=Voltage drop across diodes=1.25V.
4. Vrip=Ripple voltage=10% of Vdc.
5. Vnom=115V.
6. Vlowline=95V.
7. .9=Rectifier efficiency.

Standard Formula for Calculating Filter Capacitor

1. C = I / (2 x f x Vpp)
2. C = I / 2 x f x Vpp (assuming f = 100Hz and load current requirement as 2amp))
3. C = I / (2 x f x Vpp)

Constructing Dual Power Supply Circuit:

1. Step-I: Converting 220v AC into 12v AC using Step Down Transformer.
2. INPUT: 220V ac, 50 Hz.
3. OUTPUT: Between outer terminal and middle terminal: 12V ac, 50 Hz.
4. Step – II: Converting 12v AC into 12v DC using Full Bridge Rectifier.
5. Here, full bridge rectifier is used.
6. INPUT: 12V ac.

4 Steps to Convert 230V AC to 5V DC

1. Step Down the Voltage Level. The step-down converters are used for converting the high voltage into low voltage.
2. Convert AC to DC.
3. Smoothing the Ripples using Filter.
4. Regulating 12V DC into 5V DC using Voltage Regulator.

12v to 5v converter using a voltage divider: You can run two LEDs in series across the resistor R2 while taking input from 12V lead-acid battery or a 12v adaptor as an input. Components required: One 12v battery, 1.8k resistor, 1.3k resistor, connecting wires. This circuit is a voltage divider schematic.

The UPS converts the AC to DC by the help of the rectifier and again converts the DC power into AC power by the help of an inverter. The block diagram od UPS is shown below. The basic feature of the offline/standby inverter is to provide the backup power and protect the system from the power surges.

Standardised voltages

6500 KW-8500 KW in 8 hours. Electric locomotives are more efficient and eco-friendly than diesel locomotives. A diesel locomotive has a mileage of 4–6 litres per kilometre which varies as per the load and geographical conditions like elevation.

Here are the world’s fastest high-speed trains in commercial service, ranked by speed:

1. Shanghai Maglev: 267 mph.
2. Fuxing Hao CR400AF/BF: 249 mph.
3. Shinkansen H5 and E5: 224 mph.
4. The Italo and Frecciarossa: 220 mph.
5. Renfe AVE: 217 mph.
6. Haramain Western Railway: 217 mph.
7. DeutscheBahn ICE: 205 mph.
8. Korail KTX: 205 mph.

DC motors

Some locomotive can run on either DC or AC supply, or both. This is because DC can only provide low voltage electric, to increase the power (output) of the locomotive, the current (A) have to be higher. However, if the current is too high, the fuse will broken. In order to reduce this risk, both pantographs will up.

In a diesel–electric locomotive, the diesel engine drives either an electrical DC generator (generally, less than 3,000 horsepower (2,200 kW) net for traction), or an electrical AC alternator-rectifier (generally 3,000 horsepower (2,200 kW) net or more for traction), the output of which provides power to the traction …