ElectronicsClass

Electronics Class

This class is targeted at the beginner who wants to learn electronics. It would make a fine prerequisite to the Microcontroller Course or the HAMClass

tease

These images form a slide show and a gestalt introduction to electronics. In which we map the techniques available to hackers and their surrounding requisite building blocks.

• [[1]]mindmap

My hacking started with music and production. it wasn't exacly the tech; more for the ride.

• [[2]] WMUC main studio

Complicated behaviour arises from iteration of simple models. Learning how to operate something like this is simpler and more subtle than it looks.

• [[3]] wheatstone broadcast console

Easier to see is block diagram form; a gestural view of a complex system. WMUC recording suites and broadcast control rooms. Computing.

• [[4]] signal diagram

Why study DC/baseband/RF electronics; anachronism?

• [[5]] chill on the roof.

Space shuttle shots; APRS , RACES, field day. Social technical effects require proficiency.

• [[6]] W3EAX tower

Small systems scale into big ones. 40,000 people at Operation ceasefire (united for peace& justice) '05 at the national mall. Standing between SS, Park police and thousands of protesters.

• [[7]] ceasefire stage
• [[8]] ceasefire 40k

No always smooth sailing.

• [[9]] mars needs bolts

Building whimsey.

• [[10]] lightup dance floor

Computer control over physical objects. microcontrollers + christmas tree lights.

• [[11]] dance floor controller

Not always smooth. Electrical compatibility != political compatability

• [[12]] hhr - phear the transaxle

More small systems iterated.

• [[13]] fireworks diagram

DIY Ignition source in Berlin. in a pinch you don't need a parts catalog.

• [[14]] igniter controller

Apologies to Dakami

• [[15]] fireworks crates

Simple systems, RC control, Robots and igniters.

• [[16]] wm greek fire

Recently robotics have become accessible to experimenters. Bluto cuts, welds and hugs.

• [[17]] Welding robots!

Required Materials

(see also: our Suppliers page)

---

• Multimeter $4
  • Source: Harbor Freight

---

• Soldering Iron (25-30w) $10
  • Source: Harbor Freight

---

• Solder ( 22ga )
  • Source: Harbor Freight
  • Source: Radio Shack
  • Or ANYWHERE, really.

---

• Bread Board ( or AshClassBoard ) $10
  • Source: Mouser
  • Source: Digi-Key

---

• wire 24ga

---

• 30ga solid core wire

---

• Resistors 10kohm

---

• variable resistor 10kohm linear $1

---

• switch [[18]]

---

• leds (various)

---

• capacitor 470uf (ish) [[19]]

---

• pn2222 transistor $.03

---

• 1/8 male phono jack

Read The Fine Data Sheet:  They hide secrets in the documentation.

Metering

There are many like it but this one is mine.

• Naming of parts
• Should be a VOM - Volt Ohm Meter
  • metering modes
    • restistance - Ohms of resistance
    • voltage - Volts
    • Current - Amps/Milliamps - check the leads
    • diode check - see [Diodes]
  • leads - plugged into the right ports?
• Continuity testing
  • set the meter to the lowest resistance mode (200ohms or auto resistance)
  • or perhaps Diode check; or even beeping
  • reads "off scale" when the leads are unconnected, this is an open circuit
  • firmly touch leads together -loopback test
  • reads near 0 if the leads are crossed
• Voltage testing
  • set meter to 20Vdc or VautoDC
  • touch leads to metered points
  • the reading on the meter is the difference in voltages between the leads
  • Try AC mains!! - safety second.

SwitchLab

• use the continuity meter to diagram the electrical layout of the switch.
• solder switch to the board.
• test under power with meter voltage setting

Relays/Switches

Codespeak

• SPDT - single pole dual throw
• DPST - dual pole single throw
• 4P10T - ???

- Map this mystery switchLab

Wire

The basic wire is a pipe through which electrons can flow from the lowest voltage side to the highest (conventional current) up to the physical limits of the wire.

• Condunctor vs. Insulators
• Current limit via wire gauge [20]
• Voltage limit via insulation.
• Magnetic and Electric fields surround an energized wire (what?!)
• And wire will respond with current when moved through magnetic flux
  • Lentz law
  • Siemens, mho, ohms

Electromagnetics

• Einstein's "spukhafte Fernwirkung"
• Quantum Electrodynamics
  • Electron and photons interact - somehow
• Gauss, Maxwell and
• Permanent magnets useful - locked domains
  • Ferro materials, Ni, Co, Sr, Rb, Nb, Nd, Cr and Fe.
  • Except when they aren't - curie temperature.
• Hall effect - sensing - spaceship drives
• Motors, linear, rotary, vibrational, direct ( magnetohydrodynamic)
• Radios
  • EM probe demo
  • EM spectrum
    • DC, ELF, SLF (submarines, blue whales), AF, LF,HF, (Short wave), VHF, UHF, Microwave, weird stuff, gamma rays (the incredible hulk, gian ants).

Soldering

Hold the cold end.

Soldering ( for our purposes ) is the process of joining electrical contacts with a low melting point metal to make a mechanically and electrically strong connection.

• Restrain long hair/clothing/jewelry.
• Clean both parts of waxes, oils or debris.
  • Ethanol/Methanol/SLX
  • Flux/Rosin/Dry
• Mechanically fit connections together
• Clean and wet the iron
  • Tip should be immaculate and bright
• Heat both parts until hot
  • Cheat, use another heating element
    • quartz floodlight, sterno, propane or mean stare.
  • but not too hot - see blue smoke lab
• Apply just enough solder to wet the contact surfaces
• Wait for the connection to shine smoothly
• remove the iron an test the connection
  • yes it's hot stupid.
  • the meter should find near 0 ohms of resistance between the two parts even when mechanically stressed.
  • the meter should read "off scale" to everything that should be isolated
• Splice practice
  • Western Union Splice
  • Pigtail Splice

Speakermaking lab

materials:

• junk wire, lots of it
• magnet ( stronger is better )

Test stuff:

• multimeter
• signal generator, (or music source)
• power amp

Construction:

• Make coil of wire 24ga 1" dia, 50-400 turns.
  • use a form, marker, tp tube, pvc pipe
  • Measure impedance > 1.5 ohm
• Stick coil of wire to diaphram
• Make stator/armature
  • stick magnet to something - not too ferrous
• stick diaphram near armature (correct axis??)
• connect to amplifier; apply Rock!

Exercises for suckers:

• Use the lentz law to calculate the force generated by thingy.
• Why 8ohm speakers in the house?

Resistor

Not like the NYC variety

Resistors impede the flow of electrons across them; usually to protect components from excessive current.

• Ohm's law
• Diagonal IV curve.
• symmetric

ResistorLab

• solder resistors, meter and record;
• compare to ohms law math

BlueSmokeLab

Get this out of the way early (and often)

• turn off the switch
• Solder the 30ga wire ends on to the lab 0 area
• stow fingers away from wire
• turn on switch

Power

• Measured in watts (usally)

* .01w laser pointer
* .25w cell phone
* 1w 
* 15w car stereo
* 25w soldering iron
* 100w light bulb
* 1500w hair dryer
* 200 horsepower (750w/hp)
* 3 tons of Air conditioner capacity (3.5kw/ton)

• The notion of instant work
• Energy or work is expressed in joules (watt*second). Or perhaps (Kw*H)
• Power(watts) = Current (Amps) * Volts

Electromechanical relay is a switch that's controlled electrically.

pros

• Easy to design for
• debugging (listen for satisfying click)
• excelent isolation
• high power control/$

cons

• high drive current (mostly)
• noisy (mostly)
• slow
• moving parts (eeew)

a typical relay - map this mystery relay lab

Diode

ScaryDataSheetLab

• a favorite led [21]
• LED ( Light emitting diode ) are diodes with a clear case.
• electrons only permitted to flow in one direction: cathode to anode
  • there are exceptions [diode breakdown voltage]
• discontinuous IV curve
• diode logic
• the cathode is marked
• the diode check function of the meter can reveal the correct polarity of a mystery diode with a suspect cathode mark.

Light Emitting Diode

• the short lead is the cathode
• LED's need current limiting (see BlueSmokeLab)

LEDLab

• solder in 1kOhm resistor for the led , although you may use another if you can justify the value
• Solder in the LED, with the short lead towards the ground.

Capacitor

470uf electrolytic cap

wikipedia capacitor

Transistor

PN2222 N channel transistor

little amplifierlab

• class A amp
• DC blocking caps
• bias resistors
• fixed gain
• inverted waveform

Digital Logic

• AND C = A & B
• OR C = A | B
• NOT C = !A
• NOR C = !(A|B)
• NAND C = !(A&B)
• MUX C = select A(n) based on B(n)

IC

LM386 Audio Amplifier [22]