Digital Electronics for Computer Science | Lesson 1

Electronics for Computer Science:

Lesson 1

Introduction:

‘We electrocuted some silicon, and tricked it into thinking.’

Harvard’s CS50 Low Level C programming Video

Given that a computer is a digital-electronic appliance, a slight knowledge of digital electronics is, therefore, necessary when commencing Computer Science.

‘Voltage,’or ‘Electromotive Force,’ is ‘the force necessary to displace electrons in the direction of Real Current.’

Or:

‘Voltage,’ or ‘Electromotive Force, ’ is ‘the force necessary to displace holes in the direction of Conventional Current.’

In physics, ‘work’is defined as ‘displacement in the direction of the applied force.’

A battery, when disconnected from a circuit, is energy in potential. When we connect a battery to a circuit, we apply electromotive force. This force causes free electrons to be displaced in the direction of real current. This force causes holes, or 'positive charge,' to be displaced in the direction of conventional current.

Ohm's Law:

Given 1 volt of Electromotive force, and 1 Ohm of resistance, 1 Coulomb of Charge - or the charge of 6.241509×10^18 electrons - will pass an arbitrary point on a circuit every secend. 1 Coulomb of Charge passing a point on a circuit every second is defined as 1 Ampere of Current.

Hence:

E = IR

This is Ohm's Law.

Electromotive Force = Intensity multiplied by Resistance.

Voltage is equal to Amperage multiplied by Resistance.

Voltage=Amperage*Ohmage

I=E/R

Intensity = Electromotive Force Divided by Resistance

Amperage is equal to Voltage divided by Resistance.

Amperage = Voltage/Reistance

R=E/I

Resistance is equal to Electromotive Force divided by Intensity.

Ohmage = Voltage/Amperage

Force in newtons and Power in watts:

In the above scenario - of one volt causing one ampere of current to flow in a circuit given one ohm of resistance - one joule of energy is dissipated as heat every second. Energy is the ability to do work. Energy is the ability to displace in the direction of applied force. In electronics, energy is the ability to displace the charge of electrons in the direction of applied force.

The SI unit of force is the Newton. In a frictionless environment, one newton of force will displace a kilogram in the direction of the applied force, such that it begin to accelerate at the rate of one meter per second per second. In such a frictionless environment, should we remove the newton of applied force after a time of one second had elapsed, then the kilogram of mass would cease to accelerate, but would, because of inertia, continue to travel in the direction of the initially applied force at the velocity of 1 meter per second forever.

Newton's Second Law of Motion states that Force is equal to Mass multiplied by acceleration.

Hence:

F=ma

1N=1kg*1meter per second per second

One Watt is equal to one joule of energy dissipated every second.

Wattage can also be termed 'power.' Another formula relevant to our study of Electronics is:

P=EI

Power (measured in watts) is equal to Electromotive Force (measured in volts) multiplied by Intensity (measured in Amperes).

Power=Electromotive Force*Intensity

Wattage=Voltage*Amperage

1W = 1V*1A

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