Difference between revisions of "Signal Sources and Amplifiers"

Revision as of 17:36, 13 September 2013

Introduction

In order to record an experimental signal with high fidelity 3 issues need to be considered.

• Type of Signal to be measured
• Characteristics of the signal sources
• Type of Amplifier used to record the signal

Signal Types

There are 4 types or classes of electical signal sources which occur in various experimental situations. It is important to understand the characteristcs of these signal sources in order that they can be matched to the correct amplifier/recording system without degrading the contents of the signal source.

PLEASE NOTE: In discussing the characteristics of signal sources reference will be made to "Source Impedance" which in its most general form consists of a combination of 3 electrical elements: Resistance,Inductance and Capacitance. In most cases one of these elements will predominate, most commonly resistance. So when the term "Source Resistance" is used it implies that the impedance of the source is mainly resistive in nature. At DC or low frequencies Impedance is mainly resistive and the other elements, capacitance and inductance only come into play at higher frequencies. http://en.wikipedia.org/wiki/Electrical_impedance

These 4 classes are listed and discussed below:

Single ended - Floating

This is a brief description of a Single ended - Floating electrode. It works like this... Blah blah blah.

Single ended - Grounded with Common mode voltage

blah blah blah

Balanced - Floating

blah blah blah

Balanced - Grounded with Common mode voltage

blah blah blah

Source Characteristics

• Source Impedance
• Source Voltage
• Source Frequency content

Amplifier types

• Single ended - Grounded
• Single ended - Isolated
• Balanced - Grounded
• Balanced - Isolated