Troubleshooting 36

State three precautions that should be observed when selecting, connecting, and testing filter capacitors.

Make sure you don't plug filtering capacitors in backward because they will explode. You must drain the charge from the capacitors before you assume the circuit is dead. There can be a shock risk when using high voltage and capacitors even when off.

green

Oxygen

Explain what is meant by the term rectification as it applies to a power supply.

Rectification is the process of changing DC to AC in a power supply circuit it also helps define which type of rectifier circuit it is full-wave or half-wave.

How many diodes are required for a three-phase, full-wave bridge rectifier?

Six diodes are required for a three-phase, full-wave bridge rectifier circuit.

Explain the principle of operation of a switching power supply.

Switching the power supply you chop the unregulated dc at a high rate, then you use it to reconstruct the dc signal for the output load.

black

nitrogen

blue

nitrous oxide

white

vacuum

purple

wagd

brown

helium

What is the main advantage of using a voltage-multiplier circuit?

A voltage multiplier is cheaper than a step transformer.

The amount of reverse voltage that the diodes must withstand.

Center-taped rectifier circuits have to deal with twice the reverse voltage.

What are dc-to-dc converters used for?

DC to DC converters are well regulated and are used to change voltage levels in dc.

Explain what is meant by the term filtering as it applies to a power supply.

Filtering is used in power supplies to smooth out the ac ripple to make a purer dc waveform.

Compare half-wave and full-wave rectifier circuits with regard to the value and amount of pulsation of the dc output voltage.

Half wave rectifier circuits have dc voltage stops because it's only a half of a pulse and at frequency. Full-wave rectifier circuits have small ripples but no stoppages and is going to be at twice the supply frequency.

Compare a full-wave, center-tapped, bridge rectifier circuit with regard to: the number of diode voltage drops along the path from the transformer to the load.

The center-taped rectifier circuit has one voltage drop. The bridge rectifier circuit has two voltage drops. Full-wave rectifier circuits have two voltage drops.

State five functions that a transformer may be required to perform in its role as part of a power-supply circuit.

The five functions that transformers perform as a part of a power supply are, steps down voltages, supplies a variable ac voltage, steps up voltages, electrically separates and isolates primary circuit from the secondary circuit, and supplies separate voltages that are out of phase with each other.

State the function of a power supply.

The function of a power supply is to take the input voltage and convert it into the correct type and value that is need for the circuit.

What special overcurrent protection feature is built into most IC voltage regulators?

The integrated circuit regulator has an internal thermal shutdown circuit that helps the chip from getting overheated due to a short circuit or overload.

What is the main disadvantage encountered with switching power supplies?

The main disadvantage is the RF noise generated by the switching network.

What is one limitation of the voltage multiplier circuit?

The main limitation is the fact that there is very poor voltage regulation in a voltage multiplier circuit.

What electronic device is commonly used as a rectifier in power supplies?

The most common electric device in a rectifier circuit is the diode.

State two advantages of a three-phase, half-wave rectifier over a single-phase, full-wave rectifier

The three-phase half-wave rectifier circuit has two advantages less ripples and higher average voltage output than a single-phase full-wave rectifier circuit.

What are the two main advantages of switching power supplies over conventional linear power supplies?

The two main advantages are more output for the amount of input and it is more efficient by 85 percent.

Name two electric devices commonly used as filters.

The two most common electronic devices is a capacitor connected in parallel and choke connected in series with the load along with a capacitor.

Explain the difference between a regulated and an unregulated power supply.

The unregulated dc power supply does not deliver pure dc and changes with load. When you have a voltage regulator connected to a rectifier circuit this is called a regulated power supply.

What type(s) of transformer or alternator system(s) can a three-phase bridge rectifier be operated from?

You can use wye or delta systems to operate a three-phase bridge rectifier.

yellow

air

gray

carbon dioxide