Introduction

What electronic circuits need in order to work?
In order to work, electronic circuits need energy.

In most cases, what component provides the energy for an electronic circuit?
In most cases, the energy for an electronic circuit is provided by a power supply.

What does a power supply do?
A power supply changes the available electric energy to the form required by various circuits required by an electronic system.

What does a power supply convert Alternating Current (AC) voltage to?
A power supply converts AC voltage to a steady DC level.

What does AC stand for?
AC stands for Alternating Current.

What does DC stand for?
DC stands for Direct Current.

What is done to the Direct Current (DC) output voltage before it is made available to the electronic system?
Before the DC output voltage is made available to the electronic system, it is filtered to be accurate.

How is the Direct Current (DC) voltage maintained?
The DC voltage is maintained automatically through regulation.

What is the most common electrical power source that a power supply converts?
The most common electrical power source that a power supply converts is the power from the local power company.

What is the voltage and frequency of the power from the local power company?
The voltage and frequency of the power from the local power company is 115 volts and 50 or 60 Hz.

What are the four blocks of a basic power supply?
The four blocks of a basic power supply are:

  1. The transformer - It steps up or steps down the voltage to that required by the system.
  2. The rectifier - It changes the AC input to a pulsating DC output.
  3. The filter - It smooths out the direct current.
  4. The regulator - It eliminates the decrease in output voltage when a load is applied.

What is an example of a block diagram for a basic power supply?
An example of a block diagram for a power supply is:

AC
Input
Transformer
Bridge
Rectifier
Capacitive
Filter
Zener
Regulator
DC
Load

Situation 1: Transformer

What does a transformer consist of?
A transformer consists of two or more coils linked together by magnetic flux.

What are the names for the coils of a transformer?
The names for the coils of a transformer are:

  • The primary winding.
  • The secondary winding.

How do the coils determine whether a transformer steps down or steps up a voltage level?
The coils determine whether a transformer steps down or steps up a voltage level by the ratio of turns between the primary winding and secondary winding.

What is a turn?
A turn is a single loop of wire around a core.

What is the ratio of turns between the two windings of a transformer called?
The ratio of turns between the two windings of a transformer is called the turns ratio.

What turns ratio is needed for a transformer to step down the input voltage?
For a transformer to step down the input voltage, the primary winding needs to have more turns than the secondary winding.

What turns ratio is needed for a transformer to step up the input voltage?
For a transformer to step up the input voltage, the secondary winding needs to have more turns than the primary winding.

What is the equation that represents the relationship between the primary winding's voltage and the secondary winding's voltage?
The equation that represents the relationship between the primary winding's voltage and the secondary winding's voltage is:

What are the variables in the equation for the relationship between primary winding's voltage and the secondary winding's voltage?
The variables in the equation for the relationship between the primary winding's voltage and the secondary winding's voltage are:

  • - The number of turns.
  • - The voltage in volts.
  • - The current in amps.
  • - Indicates that it pertains to the primary winding.
  • - Indicates that it pertains to the secondary winding.

What is the equation for the relationship between the primary winding's voltage and the secondary winding's voltage also called?
The equation for the relationship between the primary winding's voltage and the secondary winding's voltage is also called the:

  1. Transformer equation.
  2. Turns ratio equation.