Electronics

AC/DC

• DC –  Direct Current
• AC – Alternating Current – United States – 120v 60Hz

Wall outlet power AC current is easier to transport a waveform

Electronics use DC current because it is easier to produce a specific result

Digital circuits 1 and 0 

 Ohms Law – V=IR

• Voltage (V) Is the analog of water pressure
• Resistance (R) Describes the restriction of flow
• Current (I) Is the rate of flow volume/unit time

Ground

• Necessary for any circuit to work.
• Charge and Ground
• Ground is where electricity wants to be.

Kirchhoff’s Laws

Kirchhoff’s Law of Voltage (KVL)

The sum of voltages in a loop or circuit is zero.

Kirchhoff’s Law of Current (KCL)

The sum of current in and out of a node is zero.

Power

• P=IV
• P=I²R
• P=V²/R

A Resistor Capacitor (RC) Circuit

https://en.wikipedia.org/wiki/RC_circuit

Electronic Components

Schematics

R	Resistor
C	Capacitor
L	Inductor
D	Diode
LED	Light-emitting diode
Q	Transistor
SW	Switch
IC	Integrated circui

Capacitor

https://en.wikipedia.org/wiki/Capacitor

Measured in farads (symbol: F)

• 1 mF (millifarad, one thousandth (10⁻³) of a farad) = 1000 μF = 1000000 nF
• 1 μF (microfarad, one millionth (10⁻⁶) of a farad) = 0.000 001 F = 1000 nF = 1000000 pF
• 1 nF (nanofarad, one billionth (10⁻⁹) of a farad) = 0.001 μF = 1000 pF
• 1 pF (picofarad, one trillionth (10⁻¹²) of a farad)

Crystal Oscillators

https://en.wikipedia.org/wiki/Crystal_oscillator

Diode

https://en.wikipedia.org/wiki/Diode

Inductor

https://en.wikipedia.org/wiki/Inductor

An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it.

A light-emitting diode (LED)

https://en.wikipedia.org/wiki/Light-emitting_diode

Resistor

https://en.wikipedia.org/wiki/Resistor

Measured in ohms  (symbol: Ω)

Resistors in series

R=R1+R2

Resistors in parallel

R = R1R2/R1+R2

Sensors

IR Receiver

Transistor

https://en.wikipedia.org/wiki/Transistor

A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. 

Mosfet

https://en.wikipedia.org/wiki/MOSFET

Photoresistor

https://en.wikipedia.org/wiki/Photoresistor

Potentiometer

https://en.wikipedia.org/wiki/Potentiometer

Surface Mount Package Sizes

Metric	Imperial	Dimensions	Dimensions	Typical Resistor Power Rating (W)
0201	008004	0.25 mm x 0.125 mm	0.010 mm x 0.005 in
03015	009005	0.3 mm x 0.15 mm	0.012 in x 0.006 in	0.02
0402	01005	0.4 mm × 0.2 mm	0.0157 in × 0.0079 in	0.031
0603	0201	0.6 mm × 0.3 mm	0.024 in × 0.012 in	0.05
1005	0402	1.0 mm × 0.5 mm	0.039 in × 0.020 in	0.1 or 0.062
1608	0603	1.6 mm × 0.8 mm	0.063 in × 0.031 in	0.1
2012	0805	2.0 mm × 1.25 mm	0.079 in × 0.049 in	0.125
2520	1008	2.5 mm × 2.0 mm	0.098 in × 0.079 in	Typical inductor and ferrite bead package
3216	1206	3.2 mm × 1.6 mm	0.126 in × 0.063 in	0.25
3225	1210	3.2 mm × 2.5 mm	0.126 in × 0.098 in	0.5
4516	1806	4.5 mm × 1.6 mm	0.177 in × 0.063 in
4532	1812	4.5 mm × 3.2 mm	0.18 in × 0.13 in	0.75
4564	1825	4.5 mm × 6.4 mm	0.18 in × 0.25 in	0.75
5025	2010	5.0 mm × 2.5 mm	0.197 in × 0.098 in	0.75
6332	2512	6.3 mm × 3.2 mm	0.25 in × 0.13 in	1
6863	2725	6.9 mm × 6.3 mm	0.27 in × 0.25 in	3
7451	2920	7.4 mm × 5.1 mm	0.29 in × 0.20 in

Surface mount technology (SMT) Used in Apple products

• 0201 Resistors
• 0201 Capacitors
• 0402 Resistors
• 0402 Capacitors
• 0603 Resistors
• 0603 Capacitors

Electronics Oven

Board Preheat: 260 Degrees Celsius for one hour

Solder Paste Properties

Common solder is an alloy from metals tin, silver, lead, and copper. The melting points of these metals are:

Metal	Melting temperature
tin (Sn)	232 °C
silver (Ag)	961.8 °C
copper (Cu)	1,084.6 °C
lead (Pb)	327.5 °C
bismuth (Bi)	271 °C

The alloys, however, have lower melting temperatures than the pure metals:

Alloy	Melting temperature
Sn63 Pb37	183 °C
Sn62 Pb36 Ag2	179 °C
Sn96.5 Ag3 Cu0.5 (SAC305)	217–219 °C
Sn96 Ag4	221 °C
Sn92.5 Ag3.5 Cu1 Bi3	213 °C
Sn42 Bi58	138 °C

For soldering with lead, the Sn63Pb37 alloy is almost universally used. For lead-free soldering, the alloy Sn96.5Ag3Cu0.5 is the most common. The alloy is also known as the abbreviation SAC305.

Profile Recommendations

The table below is a starting point for a profile for a batch oven. The optimal profile also depends on the PCB, and therefore the suitability of a profile must be verified with actual measurements.

Zone	Lead (Sn63 Pb37)	Lead-free (SAC305)
Preheat	to 150 °C in 60 s	to 150 °C in 60 s
Soak	from 150 °C to 165 °C in 120 s	from 150 °C to 180 °C in 120 s
Reflow	Peak temperature 225 °C to 235 °C, hold for 20 s	Peak temperature 245 °C to 255 °C, hold for 15 s
Cooling	-4 °C/s or free-air cooling	-4 °C/s or free-air cooling