Question

An essay about researchers experiences in designing DC power supply circuit and audio amplifier circuit to preform a speaker?

Answer 1

DC POWER SUPPLY

A basic power supply circuit will fundamentally require three main components for providing the intended results.
1. Transformer,

2. Diode

3. Capacitor

The transformer is the device which has two sets of windings , one primary and the other one is the secondary. Mains 220v or 120v is fed to the primary winding which is transferred to the secondary winding to produce a lower induced voltage there.

The low stepped down voltage available at the secondary of the transformer is used for the intended application in electronic circuits, however before this secondary voltage can be used, it needs to be first rectified, meaning the voltage needs to be made into a DC first. For example if the transfornmer secondary is rated at 12 volts then the acquired 12 volts from the transformer secondary will be a 12 volt AC acros the relevant wires.

Electronic circuit can never work with ACs and therefore this voltage should be transformed into a DC.

A diode and capacitor combination is one device which effectively converts an AC to DC, there are three configurations through which basic power supply designs may be configured.

1.Using a single diode (Half wave)

2.Using a two diodes (center tapped)

3.Using a four diodes (Bridge rectifier)

(not mentioning details and diagrams, just in brief)

AUDIO AMPLIFIER CIRCUIT

We know that a speaker converts Electrical energy into mechanical energy and produce a sound wave, and we also know that, the microphone does exactly opposite thing which produces electrical wave from the sound signal.

Amplifier is the generic term used to describe a circuit which produces and increased version of its input signal. However, not all amplifier circuits are the same as they are classified according to their circuit configurations and modes of operation.

The classification of an amplifier as either a voltage or a power amplifier is made by comparing the characteristics of the input and output signals by measuring the amount of time in relation to the input signal that the current flows in the output circuit.

However, by altering the position of this Base bias voltage, it is possible to operate an amplifier in an amplification mode other than that for full waveform reproduction. With the introduction to the amplifier of a Base bias voltage, different operating ranges and modes of operation can be obtained which are categorized according to their classification. These various mode of operation are better known as amplifier class.

Audio power amplifiers are classified in an alphabetical order according to their circuit configurations and mode of operation. Amplifiers are designated by different classes of operation such as class “A”, class “B”, class “C”, class “AB”, etc. These different amplifier classes range from a near linear output but with low efficiency to a non-linear output but with a high efficiency.