# Learn Electronics/Appendix

This is a ruf draft. Some chapters are likely to be removed others may be added. The idea is to keep a structure as Theory->Some Exercises->Experiment. This may not be possible for all chapters. Please add comments, more topics or new chapters. --Patrik 12:16, 20 July 2005 (UTC)

# Part 1 DC: Direct Current

## What is electricity?

What is electricity physicaly, What is voltage, current and resistance?

## Voltage, current and Resistance. Ohm’s Law.

Math. relation between U, I and R. Where it applies, where it doesn’t. Examples of magnitudes of values for U, I and R.
Experiment: measuring current and voltage in a simple circuit. (battery + small light bulb). Introduces how to measure these quantities.

## The Resistor.

What is a resistor, how does it looks like, how does it work. simple circuits with resistors (serie, parallel, and combinations) and how to solve them.
Expermiment: measuring resistance. Check if your calculation is correct with a ohm meter.

## Resistance of wires.

How to calculate the resistance of a certain lenght of wire. Loses in wires.
Experiment: Calculate the resistance of a piece of wire and the check your result.

## The Voltage divider.

What it is, how it works, how to calculate it. How a load (resistor from divider to ground) modifies its output. The pot-meter.
Experiment: building a voltage divider and check out the math and the load. Try out a voltage divider build with a pot-meter.

## Special resistors.

Light Dependent Resistors, Temperature dependent resistors.
Experiment: Measuring resistance of these resistors in different conditions.

## The Capacitor.

What is a capacitor. contruction, uses. Capacity (what it is, where it depends on) Charging and discharging. The RC circuit (charge and discharge graph. The meaning of the value of R*C (or tau), meaning of 5 tau.
Experiment: measuring and drawing the charge and discharge graph of an RC circuit. Check if tau (calcutated) is correct. Same for 5 tau.

## Semiconductors.

What are semiconductors. the PN junction. Diode, led and zener diode.
experiment: simple circuit (battery, diode and resistor), measure in which direction the diode blocks and in which it conducts. Same experiment with led, Getting a fixed voltage with a zener.

Next chapters of this part are optional. They may be kept for a differend part or something. These chapters may benefit from having AC to explain them completely.

## Transistors in DC.

What’s a transistor, how does it work, transistor models, basic circuits. Why its beta (HFE and Hfe. how much the transistor amplifies the basis current) is pretty useless for designing circuit (it varies too much in real life transistors. this is commonly noted as a value “between 100 and 300” or simular.).
Experiment: test a few transistor circuits. Measure the beta of a few transistors of the same type.

## Light-sensitive semiconductors.

Phototransistor, opto-couplers, photo-diode.
Experiment: Measuring some values in simple circuits with phototransistor and photodiode. building a light meter. Simple circuit with an optocoupler.

## The Field Effect Transistor or FET.

What’s a FET, how does it work. different types, uses, basic circuits. FET- transistor (dis)simularities. (dis)advantages.
Experiment: Simular experiments as the transistor.

# Part 2 Digital Electronics

## What is digital electronics

what does digital means, benefits of digital technology (in contrast to analog electronics), limits and problems of digital electronics.

## Digital Numbers and Math

What are binary numbers, how to add, substract, multiply and divide them. what are shifts. Boolean operators.

## Boolean algebra

boolean algebra, Demorgan

## Karnaugh diagrams

diagrams for simplifying digital equations

## Real Life Digital Cicuits: TTL IC's

What are IC's, what is TTL, voltage levels, how to interface them, push-pull and open collector outputs, fan-in and fan-out.
Experiment: build a digital circuit, build a larger digital circuit, apply boolean algebra to symplify and build simpler circuit, verify they are equal. Measure on which voltage levels a gate switches.

## CMOS IC's

What is CMOS. How CMOS differs from TTL, how to interface them, voltage levels, how to mix TTL and CMOS.

## Latches and Flipflops

basic Latch with gates, master-slave flipflop, J-K-Flipflop, D-flipflop.
experiment: Build a basic batch.

## Shift Registers

What are shift registers, how are they constructed

## Digital Oscillators

What, how, examples
Experiment: Build a oscillator with a 555 timer IC.