Lectures in mathematics

1. INTRODUCTION / CYFLWYNIAD
Electrical and Electronic Principles
[ICE-1301]
Dr Mohammed Mabrook
Email: m.f.mabrook@bangor.ac.uk
Room: 224
Ext: 2702
Dr Daniel Roberts
Email: d.r.g.roberts@bangor.ac.uk
Room: 221
Ext: 3855
Dr Roger Giddings
Email: r.p.giddings@bangor.ac.uk
Room: 231
Ext: 2751

2. Electricity / Trydan
 What is Electricity? / Beth yw Trydan?
 It is both Voltage & Current / Mae’n Foltedd a Cherrynt
 Electricity is the flow of charge through a Conductor → Insulators do not allow currents!
 Trydan yw llif gwefr drwy Ddargludydd → Nid yw Ynysyddion yn caniatáu cerrynt!
 Charge of Electrons / Gwefr electronau → 𝒆 = −𝟏. 𝟔 × 𝟏𝟎−𝟏𝟗
𝑪
Coulomb / Cwlomb
http://www.biography.com/peopl
e/charles-de-coulomb-9259075
Charles
Coulomb
(1736-1806)

3. Electricity / Trydan
 Why is an Electron called an Electron?
 Pam a elwir Electron yn Electron?
ἤλεκτρον Elektron

4. Current / Cerrynt
 Unit of charge? / Uned gwefr?
 Q
 Current is the flow of Charge per unit time.
 Cerrynt yw llif Gwefr bob uned amser.
 𝑰 =
𝑸
𝒕
← Simplified Version / Fersiwn Syml
 𝑰 =
𝒅𝑸
𝒅𝒕
← Units / Unedau = 𝑚𝐴 − 10−3
𝜇𝐴 − 10−6
𝑛𝐴 − 10−9
𝑝𝐴 − 10−12

5. Current / Cerrynt
 You can think of it as a flow – The current is ‘flowing’.
 Gallwch feddwl amdano fel llif – Mae’r cerrynt yn ‘llifo’.
 Flow of positive
charge (Current)
 Llif o wefr bositif
(Cerrynt)
 Flow of Electrons
 Llif o Electronau

6. Voltage / Foltedd
 You can think of it as the ‘Push’, or the ‘Potential’ that causes the current to flow.
 Gallwch feddwl amdano fel y ‘Gwthiad’, neu’r ‘Potensial’ sy’n achosi’r cerrynt i lifo.
 It is NOT a flow, it’s a POTENTIAL!
 NID yw’n llif, mae’n BOTENSIAL!
 Voltage is equal to energy per unit charge.
 Mae Foltedd yn hafal i egni bob uned gwefr.

7. Resistance - R / Gwrthiant - R
 In metal conductors, electron movement is impeded by thermally induced vibrations of
the lattice, and this hindrance to the flow is termed Resistance.
 Mewn dargludyddion metel, mae symudiad electronnau yn cael eu rhwystro gan
ddirgryniadau thermol o’r ddellten, ac mae’r rhwystr yma yn cael ei alw yn Wrthiant.
 Defnition – A circuit element has a resistance of 1 Ohm if a potential difference of 1 Volt
applied across it causes a current of 1 Amp to flow.
 Diffiniad – Mae gan elfen o gylched gwrthiant o 1 Ohm os yw gwahaniaeth potensial o 1
Folt sy’n cael ei gymhwyso drosto yn achosi cerrynt o 1 Amp i lifo.

8. Ideal Resistor
Gwrthydd Perffaith
𝐼
𝑉 𝑅
I ∝ V
R =
V
I
∴ V = IR
OHM’s LAW!
DEDDF OHM!
Ohm’s Law / Deddf Ohm
𝐼
𝑉
I =
V
R
𝐺𝑟𝑎𝑑𝑖𝑒𝑛𝑡 𝐺𝑟𝑎𝑑𝑑𝑖𝑎𝑛𝑡 =
1
R
𝑦 = 𝑚𝑥 + 𝑐
Slope / Gradient
Graddiant
‘y’ Axis Intercept
Rhyngdoriad
Echel ‘y’

9. Conductance - G / Dargludiant - G
 The ability to conduct electrical current is termed Conductance.
 Yr allu i ddargludo cerrynt trydannol yw Dargludiant.
𝐺 =
1
𝑅
Conductivity
Dargludedd
𝜎 =
1
𝜌
Resistivity
Gwrthedd

10. Passive Sign Convention / Confensiwn Arwydd Goddefol
“Whenever the reference direction for the current in an element is in the direction of the voltage
drop across the element, use a positive sign in the expression that relates the voltage to the
current.”
“Pryd bynnag fydd y cyfarwydd cyfeirio ar gyfer y cerrynt mewn elfen yng nghyfeiriad y gostyngiad
foltedd ar draws yr elfen, defnyddiwch arwydd bositif yn y mynegiad sy’n perthnasu’r foltedd i’r
cerrynt.”
𝑉
𝑠 𝑅
𝐼
𝑉𝑅
+
−

11. Passive and Active Circuit Elements
Elfennau Cylched Goddefol a Gweithredol
 Passive Circuit Elements Absorb and ‘Store’ Energy.
 Mae Elfennau Cylched Goddefol yn Amsugno a ‘Storio’ Egni.
 Dissipation (Heat Loss, Vibration) / Afradlonedd (Colled Gwres, Dirgryniad);
 Temporary Energy Storage (Capacitor, Inductors) / Storfa Egni Dros Dro
(Cynhwysydd, Anwythydd);
 Examples: Resistors; Inductors; Capacitors; Relays; Transformers /
Enghreifftiau: Gwrthyddion; Anwythyddion; Cynhwysyddion; Relái;
Newidyddion;
 Each has an Equivalent Circuit / Mae gan bob un Gylched Gyfatebol.

12. Passive and Active Circuit Elements
Elfennau Cylched Goddefol a Gweithredol
 Active Circuit Elements Deliver Energy.
 Mae Elfennau Cylched Gweithredol yn Dosbarthu Egni.
 Current and Voltage Sources (Act as Energy Sources / Ffynonellau Cerrynt a
Foltedd (Gweithredu fel Ffynonellau Egni);
 Examples: Battery; Generator; Fuel Cell; Solar Cell / Enghreifftiau: Batri;
Generadur; Cell Danwydd; Cell Solar.
 Each has an Equivalent Circuit / Mae gan bob un Gylched Gyfatebol.