Electronics Videos
I want to do a series of videos on electronics, really focusing on the parts in the basic lab setup.
Focus on making things - showing stuff on a breadboard is great.
Basic Electronics
Voltage, Resistance, Current and Ohms Law
Hook up a resistor and LED to a 9V.
- Current: electricity flowing through a point
- Resistance: how much something resists current (and voltage)
- Voltage: electrical pressure, electric potential. Measured between two points. There is a drop between any two points.
- V=RI
Find the voltage drop across the LED
Power
P = RI2
Short out the LED.
Resistor Networks
In a circuit everything acts like a resistor or a voltage source. It may change over time, but it's always true.
Voltage divider.
Resistors in series.
Resistors in parallel.
AC/DC
Just a definition, don't get into history or details.
AC changes direction, but waveform can vary. Generally a sine wave
DC always goes in one direction, but can also vary.
Using a multi-meter
To measure current, resistance and voltage.
Soldering and Power Supply
Over these videos, we'll build the basic power supply.
Breadboarding
Just a few videos to talk about how a bread board works. Do a few resistor networks with LEDs.
Basic Components
Resistors
Talk about different kinds.
Pull up and pull down resistors.
Buttons, switches and pots
Diodes
Talk about the voltage drop.
Zener Diodes
Zener current is about 10mA
Caps
Inductors
We don't have any in the lab, but they're important to understand. We can make some with coils of wire.
Transformers
Just concept. Expand homemade from previous as demo.
Relays
Again, we don't have any (and we won't build any), but helps lay groundwork for transistors.
BJT
- Bv = Ev + 0.7v
- Bi*50 = Ci
MOSFETs
These are easier to understand than BJT so start here.
Full on acts like a relay, but without any of the inductance.
Linear mode acts like a voltage controlled pot.
Gotcha
- Conducts reverse
- gate is relative to source
Easy to use N low side, tricky high side. P is more expensive.
Basic ICs
IC Intro
IC quadrants
Most of the cost of an IC is in the design and setting up manufacturing, not in the production. So ICs that are more versatile can sell more bringing their costs down. Also, a simpler design brings down the cost.
If we plot versatility against complexity we get 4 groups
- High versatility, high complexity: micro-controllers
- low versatility, low complexity: peripherals (shift register, memory, mux/demux, stepper driver)
- low versatility, high complexity: alarm clock IC, radio IC
- high versatility, low complexity: 555, op amp
IC Packages
Dip, surface mount.
Impedance
Used for reading voltage. Mosfet is high impedance.
555
555 Intro
Not a timer. Not just 3 circuits
551/Schmitt Trigger
V+, T, O, G
Compare to heater logic. Show how we can shift the center with resistor divider, but cannot change the range.
552
Add reset. Circuit can now go High and stay high and we can reset it.
553
T → Th, Tr
This lets us set the range. Also (assuming this is right) define that Th take precedent.
554
Show astable mode on 553.
554 moves discharge transistor inside.
555
Add ctrl, use it to translate between 5v and 3.3v.
Standard Circuits
Monostable, bistable and astable circuits.
Also show the diode trick to get astable mode below 50% on.
Op Amps
Basic Rules
Difference between + - is multiplied by thousands or millions. The actual value is not important.
Comparator circuit.
Voltage follower
Simple negative feedback. First with voltage divider, then with zener.
Amplifier
Basic 1+(Rf/Rg) amplifier.
Logic Probe
Build logic probe.
Audio Amps
Power loss in linear amp.
PWM and switching power supply.
Use 555 to build audio amp.
Power Supply
Build second power supply using op amps. Talk about heat sinks. Good chance to get into perf board techniques a little more
Microcontrollers
Basics
Use the Arduino to build a bunch of breadboard experiments.
Show the shift registers and lcds
Off board
Build an arduino on a breadboard. Program it with the arduino and the ftdi chip.
Perf board
Build an arduino project on a perf board.