ICs
All of the ICs described below are supplied in the DIP-8 package form. You can distinguish them by the text that is written on their top face, which includes their type number.
NE555
A 555 timer is an IC that can provide an adjustable square wave. The classic “555” name originates in the internals of the chip, where three internal 5 kΩ resistors are used to determine the characteristics of the output square wave. 555 timers are traditionally used with two resistors and two capacitors to create an astable oscillator circuit.
TLC272
The classis 272 chip is an operational amplifier, which is an active device that can amplify electrical signals. It is meant to be used with a feedback system containing for example resistors, capacitors or inductors. Different feedback systems can be used to achieve different behaviour. Most often you will find feedback systems to achieve a buffer, (inverted) amplification and active filters.
MCP6002
The MCP6002 opamp is a dual (i.e. two in one device) general purpose opamp with a rail-to-rail input and output. Rail-to-rail in and out means that the input voltage and the output voltage can be as high as the supply voltage. The supply voltage is often referred to as rail.
INA126
The INA126 chip is a so called instrumentation amplifier (INA). Instrumentation amplifiers are active components that can amplify electrical signals. Unlike the opamp, it does not need a feedback circuit, as it has one on the chip. INAs are well known for their differential gain and common-mode-rejection capabilities. This allows them to amplify very small signals while rejecting any common-mode signals. Please see the datasheet for typical applications and other necessary details.